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VOLUME IV ISSUE 1 NEWS 2018

TATA INSTITUTE OF FUNDAMENTAL RESEARCH

CELEBRATING THE UNITY OF SCIENCE : ICTS TURNS 10

4–7 January, 2018 | Discussion Meeting ICTS at Ten This is the tenth year of ICTS—TIFR since it came Over the course of this meeting, speakers from into existence on August 2, 2007. ICTS has now around the world gave broad perspective talks grown to a team of fifteen faculty members across different themes in the theoretical sciences: studying various areas in the theoretical sciences. Astrophysics and Cosmology, String theory and Over 150 programs and discussion meetings have Quantum Gravity, Mathematics, Theoretical ICTS at Ten been held. Computer Science, Condensed Matter and Celebrating the unity of Science Statistical Physics, and Physical Biology. A discussion meeting, ICTS at Ten, was held to celebrate the occasion. It was an opportunity to These areas reflect ICTS’ present profile as well The talks were held at the Chandrasekhar reflect on the journey thus far, and to go ahead as the directions it would grow into in the coming auditorium of the ICTS Campus located in north with renewed energy into our second decade, years. The talks, by a galaxy of distinguished Bangalore and were attended by over 200 through a small celebratory scientific gathering. researchers, shed light on some exciting frontier participants. ■ The theme of the meeting was ‘Celebrating the questions in these areas. Unity of Science’.

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Below here and on the next page, are a few 7 January, 2018 | Public Lecture and Panel Discussion 11 January, 2018 | ICTS Vishveshwara Lecture 14 January, 2018 | Public Lecture & Movie glimpses from the discussion meeting, ICTS at Ten. The Usefulness of Useless Knowledge Exploring the Universe with Gravitational The Science of the Man n the afternoon of Sunday, the 7th of January, ORobbert Dijkgraaf, IAS, Princeton delivered Waves: From the Big Bang to Black Holes from the 9 Dimensions the public lecture on ‘The Usefulness of Useless Knowledge’ emphasizing the role of fundamental research, which seems useless at times but often later turns out to play a significant role in technologies serving humankind.

The lecture was followed by a panel discussion on:

• Global spread of science in the 21st century – what are its dynamics and how is it going to happen?

• Role of three entities in society in funding scientific research – funding coming from Govt, individual philanthropy and corporate sectors and how can they be most effective in doing so.

• Fundamental science in India – what role it has played in India and what role should it play. As well as the role of Science education.

The panel was moderated by Rajesh Gopakumar and the panelists were introduced by Spenta Wadia. The panelists were Manjul Bhargava (Princeton University), Jennifer Chayes (Microsoft n the 11th of January, ICTS witnessed Thorne talked about the two types of waves n 14th January, there was a talk by Hirosi Research, New England), David Gross (KITP, Santa Oa gathering of over 1500 students and that can propagate across the universe: OOoguri, Fred Kavli Professor of Theoretical Barbara), (Co—Founder, Infosys Narayana Murthy members of civic society who had come to attend Electromagnetic waves and gravitational waves. Physics and Mathematics, Director of Walter Burke Technologies) and K. VijayRaghavan (NCBS—TIFR the first ICTS Vishveshwara Lecture (the public Galileo initiated electromagnetic astronomy 400 Institute for Theoretical Physics, Caltech on ‘The & Secretary, DBT, Govt. of India). ■ lecture series through which ICTS celebrates the years ago by pointing a telescope at the sky and science of the man from 9 dimensions’, followed by life and work of C. V. Vishveshwara) delivered discovering the moons of Jupiter. LIGO recently a 3D dome movie screening of ‘The Man from the by Kip S. Thorne, Feynman Professor of initiated gravitational astronomy by observing 9 Dimensions’. This was a special premiere of this Theoretical Physics at Caltech and 2017 Nobel gravitational waves from colliding black holes. spectacular movie in India at the Sky Theatre, JN Laureate in Physics on ‘Exploring the Universe Thorne described this discovery, the 50 year Planetarium, Bangalore. The Chief Guest for this with Gravitational Waves: From the Big Bang to effort that led to it, and the rich explorations that special event was Sudha Murty from the Infosys Black Holes’. lie ahead. ■ Foundation. ■

The list of speakers can be found at www.icts.res.in/discussion-meeting/icts-at-ten All the ‘ICTS at Ten’ lecture videos are available on the ICTS YouTube channel – www.youtube.com/channel/UCO3xnVTHzB7l—nc8mABUJIQ

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spacetime has a fixed geometry and there is no force is negative, in contrast to the observed positive For example, initially it described only static of gravity. Yet Maldacena showed that they admit cosmological constant, or "dark energy"), it is states, but subsequent work by Veronika Hubeny, QUANTUM ENTANGLEMENT AND a radically different alternative description, which natural to speculate that, even for our universe, the Mukund Rangamani, and Takayanagi generalized is classical, has a dynamic spacetime geometry, and apparently smooth, classical spacetime is really just a it to dynamical processes. Their version has been includes the force of gravity. And there is another representation of a collection of a very large number used, for example, to better understand how THE GEOMETRY OF SPACETIME important difference: the GR description has an of strongly interacting quantum—mechanical certain systems thermalize. The formula has been MATTHEW HEADRICK extra dimension of space compared to the QM degrees of freedom; to speculate, in other applied extensively to holographic models of description. For example, in certain cases the QM words, that space, time, and gravity are emergent real—world systems, such as nuclear matter and system lives in ordinary three—dimensional space phenomena. superconductors, in order to understand their lmost since quantum mechanics and general correlations that are intrinsic to the state, rather combining GR and QM, in other words of finding a while the GR description has four spatial dimensions. physics better. At a more fundamental level, one relativity were discovered around a hundred than reflecting any statistical description or lack consistent quantum theory of gravity, is famously We emphasized above that entanglement is one of A In others cases, the QM has two dimensions (lives school of theorists, led by Mark Van Raamsdonk, has years ago, theoretical physicists have been struggling of knowledge on our part. Such correlations are difficult, and has been partly solved by string theory. the features of QM that most sharply distinguishes on a plane), while the GR, like our world, has three. posited that entanglement should be viewed as the to unify them. Step by step, this struggle has borne called entanglement. Entanglement is at the root "Partly" means that, while string theory in principle it from classical mechanics. If we take a holographic Such a relationship is analogous to a hologram, in basic building block of holography, and attempted fruit, often in surprising ways and with unexpected of many of the counterintuitive features of QM; this is a fully consistent quantum theory of gravity, and system and consider it in the QM description, then which a pattern on a piece of two—dimensional film to build up GR from this starting point. A notable implications. Forty years ago, string theory, the was emphasized by Einstein, who called it "spooky while we can use it to do certain calculations that its different parts will naturally be highly entangled gives rise to the appearance of a three—dimensional success has been the derivation of the Einstein first genuine quantum theory of gravity, was found. action at a distance". It also plays a central role in simultaneously involve QM and GR (for example, with each other. Does that entanglement manifest object. For this reason, the correspondence between equation, the fundamental equation governing GR, Twenty years ago, a remarkable discovery came out technologies powered by quantum mechanics, involving scattering of gravitons, the particles that itself somehow in the GR description? Given that QM and GR discovered by Maldacena is called from the Ryu—Takayanagi formula. of string theory: quantum mechanics and general such as quantum cryptography and quantum carry the force of gravity), we do not yet have a GR is classical and therefore does not admit the ‘holographic’. relativity are not actually two separate theories, but computation. complete understanding of the theory. For this possibility of entanglement, one might think that More generally, Ryu and Takayanagi's discovery rather, in some sense, two sides of the same coin. reason, string theory has not yet answered many of Before proceeding, we should emphasize one point: it cannot. Surprisingly, however, the answer is yes. has revealed a deep and rich connection between We now turn to general relativity (GR). This theory, This connection between quantum mechanics and the thorniest questions at the intersection of QM It may at first sight seem shocking that a quantum Not only does the entanglement manifest itself in GR and quantum information theory. By now, which is necessary for an accurate description of general relativity goes by the name ‘holography’. Ten and GR, such as the black—hole information puzzle system can ever appear to be classical. In fact, this GR, it does so in a beautiful, geometrical way. In this connection has been extended far beyond systems on the scale of the solar system and larger, years ago, theorists studying holography discovered or the nature of the big bang. We also don't yet is the least surprising aspect of holography. After 2006, Shinsei Ryu and Tadashi Takayanagi proposed just entanglement to touch on such concepts as radically alters our notions of space and time: these that there is a direct and beautiful relation between know whether the real world is actually described by all, any macroscopic object, such as a tennis ball, a formula for the degree of entanglement between quantum error correction, tensor networks, and are united in a single four—dimensional continuum, entanglement, a central concept in quantum string theory, or by some other quantum theory of being composed of electrons and other particles, is two parts of a holographic quantum system, algorithmic complexity. In fact, interesting new whose geometry is variable and dynamic, responding mechanics, and spacetime geometry, a central gravity. strictly speaking governed by QM, yet in describing quantified by a certain entropy. According to their developments in quantum information theory to the matter embedded in it, while dictating concept in general relativity. In this article, I will its motion quantum effects get washed out and formula, this "entanglement entropy" is given by have already been spurred by its connections how that matter moves. This interaction between In 1997, building on investigations of black holes attempt to convey a bit of the story of holographic classical mechanics is perfectly adequate. The the area of a certain minimal surface in the spatial to holography. String theorists and quantum spacetime geometry and matter gives rise to the in string theory, Juan Maldacena discovered a very entanglement, and why it is so exciting. systems considered by Maldacena similarly contain a geometry on the GR side. A minimal surface is one information theorists now routinely meet at force of gravity. surprising direct connection between QM and GR. very large number of physical degrees of freedom; in with the smallest possible area subject to some conferences and collaborate on papers, a state of I will start by explaining a few essential aspects He showed that certain quantum—mechanical Although clearly a part of modern physics, GR is this case, a very large number of fields. Such systems boundary condition; for example, a soap bubble affairs that would have been hard to imagine fifteen of quantum mechanics and general relativity. theories are———in a very peculiar sense———also labelled by physicists as a "classical" theory, by which had already been studied by theorists for decades, stretched across a loop of wire will arrange itself years ago. Quantum mechanics (QM), which is necessary for governed by GR. The QM theories in question are we mean that it does not obey the rules of QM: the and the fact that the collective behavior of these into a minimal surface. The mathematical problem an accurate description of systems on atomic and similar to the one that governs the strong nuclear In my view, the discovery of holographic variables specifying the geometry of spacetime, as fields is well described by classical mechanics was of finding minimal surfaces is called the Plateaux smaller length scales, radically alters our notion force which binds quarks inside atomic nuclei (called entanglement and its generalizations has been one well as the positions and momenta of particles in already anticipated in the 1970s by Gerard 't Hooft. problem. Ryu and Takayagani thus asserted that, of the state of a physical system. While a particle quantum chromodynamics). In these theories, of the most exciting developments in theoretical spacetime, take on definite values. The problem of However, concrete and useful descriptions of this in holographic systems, quantifying entanglement in classical mechanics has, at any instant of time, physics in this century so far. What other new collective behavior were lacking before Maldacena. translates into a Plateaux problem. The area here both a definite position and a definite momentum, concepts are waiting to be discovered, and what The fact that this description in some cases is GR, is measured in Planck units, the fundamental units according to the famous Heisenberg uncertainty other unexpected connections? We can’t wait to find with an extra dimension of space, was completely of quantum gravity. In relating the entanglement principle in QM it can have neither. This uncertainty out. unexpected, and remains deeply mysterious. entropy to a surface area, Ryu and Takayanagi leads to the strange phenomenon of entanglement. were inspired by the relation discovered by Jacob Matthew Headrick is a theoretical physicist and a Entanglement is a kind of correlation between In the type of quantum theory considered by Bekenstein and Stephen Hawking in the 1970s, faculty member at Brandeis University, USA. ■ different parts of a quantum system, for example Maldacena, not only are there a large number of giving the entropy of a black hole by the area of its in the positions of different particles. In classical physical degrees of freedom, but they interact very event horizon in Planck units. (See the figure for an mechanics, correlations between different parts of a strongly with each other. Theories with strong illustration of the Ryu—Takayanagi formula.) system occur only in a statistical sense, when we are interactions are very difficult to study by traditional ignorant of the true state of the system. Consider, theoretical methods. However, their equivalence to Since 2006, the study of holographic entanglement for example, a distribution of possible positions GR makes them relatively tractable, because classical has multiplied in many directions. Since Ryu and of a pair of particles. If in that distribution the theories are almost always much easier to deal Takayanagi essentially guessed their formula, particles are always close to each other, then their with than quantum ones. Holography has therefore rather than deriving it, a major thrust initially was positions are statistically correlated. On the other proven incredibly useful for modelling a wide to check its validity by comparing its predictions hand, in any actual state, every physical variable variety of strongly—interacting quantum systems, both against first—principles calculations and has a definite value, including those specifying the Fig. 1: According to the holographic correspondence, certain two—dimensional quantum—mechanical (QM) systems are equivalent from colliding atomic nuclei to high—temperature against known general properties of entanglement. states of the parts (for example, the position of each to three—dimensional general relativity (GR). The plane where the QM system lives is the top boundary, shaded in blue, of the GR superconductors. Conversely, holography also It passed all of these tests with flying colors, individual particle); since there is no uncertainty, space. The latter space is warped, with distances being larger than they appear near the top and smaller near the bottom. According provides a new perspective on GR and gravity. While and this process deepened our understanding of there is no room for correlations. In QM, however, to the Ryu—Takayanagi formula, if we divide the QM plane into two parts, then the degree of entanglement between them is given the GR theory that governs holographic systems is holographic entanglement considerably. Another the fact that even in a fixed state physical variables by the area of the minimal surface anchored on their mutual boundary———here, the red circle. Because of the warped geometry, not exactly the same as the one that governs our major thrust has been to generalize the formula, in do not take on definite values opens the door to this minimal surface, shown in orange, hangs down rather than stretching flat across the circle as one might expect. universe (in particular, the cosmological constant order to make it as broadly applicable as possible.

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First Observational Evidence the bodies. In the last of the equalities I have used by a sensitive detector built here on Earth, even First concrete evidence for the existence of Kepler’s second law v2 = GM/r. We can rewrite the if the merger occurs billions of light years from gravitational waves came from radio observations centripetal force as: F = G (v/c)⁴. Since v is less than Earth. Other potential sources of gravitational GRAVITY’S FATAL ATTRACTION F of a binary pulsar system called PSR 1913+16, c, the centripetal force is always smaller than G , waves include supernovae, rapidly spinning neutron B. S. SATHYAPRAKASH F discovered by Russel Hulse and Joseph Taylor in coming close to it when v ~ c. stars, stochastic backgrounds produced in the early 1976. This binary consists of two neutron stars, each Universe etc. The question then was what sort of To make v close to c you would need to put together he 2017 Nobel Prize in physics was awarded Enter Einstein Soon after proposing his new theory of gravity, of mass approximately 1.4 times that of Sun, in an detectors would be sensitive enough to detect such binary companions in a very tight orbit. But most to Rainer Weiss, Barry Barish and Kip Thorne In the end, Einstein was able resolve precession of Einstein showed that his equations of general elliptical orbit around each other, with a period of sources. T astronomical binaries (planetary orbits, binaries ‘for decisive contributions to the LIGO detector and perihelion of Mercury in 1915 with his new theory of relativity naturally gave rise to the phenomenon about P ~ 7.75 hours. General relativity predicts that of main sequence stars, binary white dwarfs etc.) Laser Interferometer Detectors the observation of gravitational waves.’ What is gravity, the general theory of relativity. In this theory, of gravitational radiation. However, not even due to loss of energy and angular momentum to would begin to touch each other far before v can As gravitational waves propagate through space, LIGO, what are gravitational waves and why was a all forms of matter and energy can produce gravity Einstein was convinced of their physical reality or gravitational waves the orbital period should change approach c. However, in the case of black—hole they stretch and squeeze space in the same manner Nobel Prize given for their observation? These are including gravitational energy itself. This nonlinearity how one might detect them. This was because by 76.5 microseconds each year. and neutron—star binaries, together referred to as as the Sun and Moon cause tidal deformation of the questions I wish to pursue in this article and tell of gravity, Einstein showed, could fully explain the the formulation of a relativistic theory of gravity Because PSR 1913+16 is in an elliptical orbit it is compact binaries, v can get close to c for very tight Earth. Consequently, the distance between a pair you how gravity’s fatal attraction leads to ‘cosmic orbital motion of Mercury. required mathematical objects (e.g., the metric possible to use the point of closest approach, or orbits; it is only in such cases that gravitational waves of free test masses would oscillate in harmony as cannibalism.’ tensor) endowed with more degrees of freedom Einstein’s theory has had deeper impact on periastron, as a reference point to monitor the produced are the largest ever possible, but they gravitational waves pass by. As with tides, the bigger than were physically necessary so that the theory A Brief History of Gravity: Tycho Brahe to our understanding, not just of gravity but the change in the orbital period of the system. If the would remain in this phase for only a few minutes or the separation of test masses, greater will be the could be used by all observers, whether they were in Urbain Le Verrier very structure of space and time. According to orbital period is constant, as one would expect seconds. But how would you put a binary in a tight extent of deformation caused by the waves. By an inertial or non—inertial reference frame2. General Gravity is the oldest force known to us. It took Newton, space is rigid, time intervals are absolute, in Newtonian gravity, the two stars would be at orbit? monitoring the distance between free test masses relativistic equations are valid for all observers but meticulous observations by Tycho Brahe and his and physical interactions that take place in the periastron after any integer multiple of the period one can, in principle, detect gravitational radiation. there is a prize to pay: one has to deal with many Binary black holes and neutron stars could form from assistants in the 16th century to discover that immutable arena of space and time don’t affect it P measured at some reference time. So, after a time However, even the most powerful events cause a spurious quantities and recognizing the true physical R an astronomical binary of massive stars. Central planets, instead of being random wanderers, followed in anyway. In Einstein’s special relativity, space and T=n P , the binary should have completed n orbits miniscule change (less than 1/1000 of the diameter degrees of freedom took decades after the theory R regions of stars are very hot. They burn hydrogen, predictable paths. One of Brahe’s assistants was time are unified and could transform into each other. or n P − T should be zero, where P is the actual of a proton) in distance between test masses that was formulated. A A helium and other elements to produce high energy Johannes Kepler, whose careful analysis of the data In particular, observers who are in relative motion period – the time interval between two consecutive are separated by a few kilometers. Detecting such radiation at their cores. The resulting radiation revealed the three laws of plenary motion that we assign different time and length intervals between Theoretical work by Herman Bondi, Felix Pirani and periastron passages. If, however, the period length changes is a formidable technical challenge. pressure holds stars from collapsing against their still teach today: (1) planets follow elliptical paths the same physical events. Although space and time Igor Robinson in the late 1950’s resolved conceptual decreases then n P – T would be negative. As shown A own gravity. A binary black hole or neutron star Rainer Weiss was among the first to realize that with the Sun at their focus, (2) a line connecting a are unified, the spacetime itself is a rigid structure in difficulties that plagued theorists for decades, by in Figure 1, the data shows a steady decrease in the could form when massive stars exhaust their nuclear Michelson interferometers, that are routinely used planet and the Sun sweeps out equal areas in equal special relativity. showing that wave degrees of freedom in general orbital period, exactly as predicted by Einstein’s fuel and cannot hold out against their self—gravity to measure the speed of light in a physics lab, could times, and (3) the square of the period of a planet relativity were not spurious but carried real physical theory of gravity. Upon unifying special relativity with gravity, any longer. But a compact binary that forms in this be used to detect gravitational waves. He also is proportional to the cube of its semi—major axis. energy, and linear and angular momentum from their Einstein found that the structure of spacetime, in Strongest Sources way would be initially very wide and an extremely recognized the hurdles that one must overcome in These laws paved the way for Newton to discover his sources to infinity. American physicist Joseph Weber particular how it is curved, was determined by mass In general relativity, the magnitude of curvature weak source of gravitational waves. However, this making a sensitive detector and how they might be theory of gravity. was the first to appreciate their significance. He built and energy. John Wheeler captured the essence produced is proportional to mass and energy density loss of radiation can make the two compact objects mitigated. The basic principle behind these detectors bar detectors for observing gravitational waves from What made these deductions possible was not of Einstein’s general relativity by famously saying of matter. The constant proportionality is G/c4, spiral in towards each other and after hundreds of is to measure the differential change in length of the cosmic events. The sensitivity of his detectors was just the design and construction of astronomical ‘matter tells spacetime how to curve and in turn where G is Newton’s gravitational constant and c is millions of years get so close that their speeds would interferometer arms using a high—power laser and not good enough to observe radiation from even the instruments (such as, the quadrant and sextant), spacetime tells matter how to move.’ What is this the speed of light. It has dimensions of 1/force. This reach the speed of light and they would merge mirrors suspended at the ends of the arms as test most catastrophic events such as supernovae in our but their precise and periodic calibration. The curvature of space and time? force is enormous: GF ≡ c4/G 1044 N. It implies that together in a big burst of radiation. masses. Weiss and Thorne were among key scientists own galaxy. latter allowed positions of planets to be recorded only when stresses in a system are large enough to who proposed to build the Laser Interferometer Warped and Dynamical Spacetime ≃ For a short duration at the time of merger the to phenomenal accuracies of an arc minute or produce forces this big can we expect the warpage Gravitational Wave Observatory (LIGO, for short). Warpage of space causes proper distances1 between luminosity in gravitational waves from a binary black less. Measurement accuracies have been critical 0 of spacetime to be perceptible. So, what sort of From the beginning, they realized that this will not test masses to change, e.g. a pair of test masses hole, no matter how massive they are, exceeds the for breakthroughs throughout the history of systems experience this force? As stated before, be just a fundamental physics experiment to detect appear to come closer together as they fall towards −5 luminosity of the entire Universe in light. So, these science. Indeed, astronomical observations made accelerated masses generate gravitational waves. gravitational waves to prove their existence but an the center of the Earth. Curvature of time is to sources are literally the most powerful sources in over more than one—hundred years showed that observatory that could help us understand how the do with the rate at which clocks tick, e.g. clocks −10 Therefore, let us consider a binary system of stars the Universe. For this reason, Kip Thorne argued, Mercury’s elliptical orbit around the Sun was not physical universe works by using this new radiation at the bottom of Eiffel Tower would tick slower of total mass M, with rotational speed v. The the final few minutes and seconds of binary black fixed but exhibited apsidal precession. A systematic as an observational tool. The idea was similar to relative to those at the top. Moreover, changes in −15 centripetal force experienced by the two stars is holes and neutron stars will be the most powerful analysis of the data led Urbain Le Verrier in France extending astronomical observations from optical the distribution of mass and energy, in particular F = Mv2/r = v4/G, where r is the distance between sources of gravitational waves and could be detected to conclude in 1859 that Newtonian gravity could to infrared radiation, radio waves, x—rays, gamma— accelerated masses, would cause the warpage −20 not fully account for the measured precession of of spacetime to change as well. The change in 575 arc seconds per century. He worked out that warpage, according to Einstein, propagates from the −25 the tidal tug of the outer planets contributed 532 source at the speed of light and these will be seen as arc seconds. To explain the apparent discrepancy −30 causing change in proper distance between free, test between observation and theory, Le Verrier Cumulative period shift (s) masses. These propagating ripples in the curvature proposed the existence of an unseen planet even −35 of spacetime are called gravitational waves and the closer to Sun than Mercury that could produce the amplitude of the waves is measured by the strain necessary tug. However, no such object was ever −40 h = ΔL/L they cause in the distance L between free found and the precession of perihelion remained a 1975 1980 1985 1990 1995 2000 2005 masses. puzzle for half—a—century. Year Fig. 1: The plot shows cumulative shift of periastron time, which decreases in time due to decrease in the orbital period Fig. 2: LIGO Hanford (left), LIGO Livingston (middle) and Virgo (right) interferometers. LIGO detectors both have 4km arms while Virgo has 3km arms.

www.icts.res.in www.icts.res.in PHYSICAL REVIEW LETTERS week ending PRL 116, 061102 (2016) 12 FEBRUARY 2016 properties of space-time in the strong-field, high-velocity the coincident signal GW150914 shown in Fig. 1. The initial regime and confirm predictions of general relativity for the detection was made by low-latency searches for generic nonlinear dynamics of highly disturbed black holes. gravitational-wave transients [41] and was reported within three minutes of data acquisition [43]. Subsequently, matched-filter analyses that use relativistic models of com- II. OBSERVATION 8 | ICTS NEWS | VOLUME IV | ISSUE 1 2018 pact binary waveforms [44] recovered GW150914 as the 9 On September 14, 2015 at 09:50:45 UTC, the LIGO most significant event from each detector for the observa- Hanford, WA, and Livingston, LA, observatories detected tions reported here. Occurring within the 10-ms intersite

rays but also neutrinos and cosmic rays. masses are 29 and 36 solar masses. In Figure 3, And Then There were Three on the sky by triangulation, which requires at least the largest gravitational—wave frequency we see LIGO ended O1 in Jan 2016 and began its second three detectors to accurately pin point the source. LIGO was built at two sites in the United States, is about 250 Hz and this corresponds to an orbital observing run (or O2) in November 2016. Between With the two LIGO detectors it was not possible to Livingston LA and Hanford WA, under the leadership frequency (which is half of the gravitational—wave November and July LIGO discovered two more binary localize the source to better than about 1200 square of Barry Brish, who served as its director from 1996 frequency) of 125 Hz. From Kepler’s law, we black hole mergers, GW170104 and GW170608 (see degrees. When Virgo joined LIGO in August 2017, to 2006. With 4 km arms, LIGO is the largest and conclude that the radius of the orbit, for a total mass Table I). Virgo joined O2 in August 2017. Addition the very first source they jointly detected was the most sensitive detector in the world. France and Italy of 65 solar masses, is about 240 km. of a third detector to the network was a landmark merger of a pair of black holes of 25 and 30 solar jointly built Virgo, near Pisa, Italy. Virgo is also an event as at least three non—collocated detectors masses at a distance of about 540 Mpc and the interferometric detector and consists of 3 km arms. The orbiting masses must therefore be at best half are required to fully reconstruct the properties of an source was localized to within 60 square degrees. Figure 2 shows aerial views of these detectors. of orbital radius, or 120 km. At the present time, the incident gravitational waves. LIGO and Virgo have Moreover, for the first time it was possible to only objects that we know that are so massive and so far observed six binary black hole mergers. The measure the polarization of the waves, which turned First Observation and Discovery occupy so little space are black holes. This does not LIGO and Virgo were operated during 2006—2010 characteristics of the observed systems are shown in out to be consistent with the prediction of general mean they are not anything else. It will take many and jointly took data for over a year. During the Table I and their masses and waveforms in Fig. 4. relativity. years before we can be certain that objects this big initial operation, they failed to make any detection. are not some other exotic objects. The mass of the It is immediately apparent that the Universe is awash Observation of a Binary Neutron Star Inspiral This was not surprising as theoretical calculations merged black hole was determined to be 62 solar with a spectrum of black hole masses. From the LIGO and Virgo were built to observe coalescence of had indicated that it would be necessary to improve mass. This is 3 solar mass less than the total mass observed population of black holes, we can hope neutron stars, the final few minutes in the life cycle the sensitivity beyond initial LIGO to make a firm of the progenitor binary and was entirely converted to one day learn how black hole binaries form and of a system similar to PSR 1913+16. The merger of detection. Coalescence of binary black holes and to gravitational radiation – pure oscillation of evolve. However, it is queer that black hole effective such a system, it has long been speculated, would neutron stars are very rare phenomena and occur spacetime. spins (see Table I) are all clustered around a value of not just produce a burst of gravitational waves only once in about a million years in a typical galaxy. zero. The effective spin is the mass—weighted sum but the aftermath of the merger would result in Therefore, it was essential that the detectors Indeed, LIGO’s debut event constitutes a triple of the black hole spins projected in the direction of a cosmic firework in the entire electromagnetic were sensitive enough to observe sources from a discovery: the first direct detection of gravitational the orbital angular momentum. It is possible that the spectrum, from gamma—rays and x—rays, all the cosmological volume that contained millions of waves, first observation of a black hole binary and companion black hole spins are titled randomly with way to optical, infrared and radio waves. Of great galaxies before a detection could be made. first recording of the birth of a new black hole. respect to the orbital angular momentum, but this importance among these is the radiation that is Before LIGO’s discovery, astronomers believed that Both LIGO and Virgo began upgrading around 2010. would not lead to a low value of effective spin for produced by the formation and decay of heavy black holes that formed from stars could not be FIG.Fig. 1. 3: The gravitational—wave gravitational-wave event event GW150914 GW150914 observed observed by bythe the LIGO LIGO Hanford (H1, left column panels) and Livingston (L1,(right right every observed system. It is also possible that black elements (heavier than iron; lanthanides, for column panels) detectors. Times are shown relative to September 14, 2015 at 09:50:45 UTC. For visualization, all time series are filtered After the upgrade, LIGO began its first observing column panels) detectors. Times are shown relative to September 14, 2015 at 09:50:45 UTC. For visualisation, all time series are heavier than about 20 solar masses. LIGO’s discovery with a 35–350 Hz bandpass filter to suppress large fluctuations outside the detectors’ most sensitive frequency band, and band-reject run (or O1) in September 2015 and in the very first hole spin magnitudes are intrinsically very small but example) by rapid neutron capture process, in the filtered with a 35—350Hz bandpass filter to suppress large fluctuations outside the detectors' most sensitive frequency band, and has already caused a paradigm shift in how we now filters to remove the strong instrumental spectral lines seen in the Fig. 3 spectra. Top row, left: H1 strain. Top row, right: L1 strain. it is not easy for stars to turn into non—spinning hot and high energy eject that is produced in the band—reject filters to remove the strong0.5 instrumental spectral lines seen in the spectra. week of its operation observed gravitational waves GW150914 arrived first at L1 and 6.9þ−0.4 ms later at H1; for a visual comparison, the H1 data are also shown, shifted in time by this think black holes might form in the Universe. black holes; they have to get rid of their large aftermath of the collision of the two neutron stars. amountTop row, and left inverted: H1 strain. (to accountTop row, forright the: L1 detectors strain GW150914’ relative orientations). arrived first Secondat L1 and row: 6.9 Gravitational-wave ms later at H1; for strain a visual projected comparison, onto each the from the inspiral and merger of a pair of black holes detectorH1 data in are the also 35– 350shown, Hz band.shifted Solid in this lines time show by this a numerical amount relativityand inverted waveform (to account for a system for the withdetector's parameters relative consistent orientations). with those in a galaxy 1.3 billion light years from Earth. The During the first observing run in 2015, LIGO angular momentum before they collapse. Finally, Detailed calculations showed that neutron star recoveredSeconds fromrow: Gravitational—wave GW150914 [37,38] confirmed strain projected to 99.9% onto by each an independent detector in calculation the 35—350 based Hz band. on [15] Solid. Shaded lines areas show show a numerical 90% credible regions for two independent waveform reconstructions. One (dark gray) models the signal using binary black hole template waveforms signal first arrived in Livingston and 7 milliseconds observed two other black hole binary mergers, a it is plausible that we are observing the merger of collisions could well be the environments in which relativity waveform for a system with parameters consistent with those recovered from GW150914 confirmed to 99.9% by an [39]. The other (light gray) does not use an astrophysical model, but instead calculates the strain signal as a linear combination of later in Hanford. highly significant event GW151226 on December 26 primordial black holes, in which case small intrinsic heavy elements like gold, silver, platinum, uranium, sine-Gaussianindependent wavelets calculation.[40,41] Shaded. These areas reconstructions show 90% credible have a 94% regions overlap, for two as shownindependent in [39]. waveformThird row: reconstructions.Residuals after subtracting One (dark the filteredgrey) models numerical the relativity signal using waveform binary from black the hole filtered template detector waveforms. time series. TheBottom other (light row: Agrey) time-frequency does not use representation an astrophysical[42] model,of the and a statistically less significant event LVT151012 spins are natural. The observed population is still etc., found here on Earth are produced. The signal observed in Livingston and Hanford strainbut instead data, showing calculates the the signal strain frequency signal as increasing a linear combination over time. of sine—Gaussian wavelets. These reconstructions have a 94% on October 12 (see Table I), confirming that the small and measurement errors are large and so we overlap. (after shifting the Hanford signal to account for In fact, binary neutron star mergers were believed to first discovery was not a one—off, rare event, and cannot make definitive conclusions yet about the Third row: Residuals after subtracting the filtered numerical relativity waveform from the filtered detector time series. be progenitors of short gamma—ray bursts (SGRBs), 061102-2 the time—delay and swapping the sign because formation mechanism of these black holes. Bottom row: A time—frequency representation of the strain data, showing the signal frequency increasing over time. that LIGO had begun a new observational era in Hanford’s interferometer arms are oppositely intense flashes of high energy gamma radiation that astronomy. oriented relative to Livingston) is shown in Figure Gravitational wave detectors can localize sources last for only a second or two and yet could be seen GW150914 LVT151012 GW151226 GW170104 GW170609 GW170814 3. Also plotted is the prediction of general relativity that best fits the data. Starting from a frequency of Signal— 30 Hz, the signal lasted for about 200 milliseconds to—noise 24 10 13 13 13 15 Ratio and 10 gravitational wave cycles (or just 5 orbits). Primary The amplitude of the signal grows until it reaches a 36 23 14 31 12 31 weight frequency of about 300 Hz, after which the signal dies out exponentially. The only interpretation for Companion 29 13 8 19 7 25 mass the sudden disappearance of the signal is that two bodies that produced the signal merged with each Remnant 62 35 21 49 18 53 mass other and thus stopped rising ripples in the curvature of spacetime. Effective —0.06 0.03 0.21 —0.12 0.07 0.06 spin From the frequency at which the signal amplitude Remnant peaked we can deduce the total mass of the system 0.68 0.66 0.74 0.64 0.69 0.70 spin and this turns out to be about 65 solar masses. Distance in From the rate at which the signal’s frequency 420 1020 440 880 340 540 Mpc increases from 30 Hz to 250 Hz we can compute a

Table I: Properties of binary black holes detected so far. GW170814 was detected by both LIGO and Virgo, all others were detected combination of the component masses called the 3 Fig. 4: Black holes observed in gravitational waves. The left panel shows masses of binary companions and of the merger remnant. The right panel shows gravitational waveforms for the first by the two LIGO detectors. All masses are given in units of solar mass. chirpmass , which turns out to be 28 solar masses. These two measurements imply that the component four detections as observed by LIGO. www.icts.res.in www.icts.res.in 10 | ICTS NEWS | VOLUME IV | ISSUE 1 2018 11

at billions of light years from Earth. Although gamma constellation of Hydra, and measured the distance to first black holes form and how did they grow to ray observatories like SWIFT, INTEGRAL and FERMI be about 40 Mpc. FERMI and INTEGRAL gamma—ray become millions to billions of solar masses found have detected scores of SGRBs, there has been no observatories recorded a short burst just 1.7 s after in nuclei of galaxies? What drove the expansion of THE SCIENTIFIC LEGACY OF conclusive observation of the expected afterglow the merger thus confirming the long—held view that the Universe throughout cosmic history, is it dark in other parts of the electromagnetic spectrum. No SGRBs came from the coalescence of neutron stars. energy (cosmological constant or its variants) or one knew for sure but simultaneous observation of The event was identified by optical and infrared modification of general relativity that can explain the STEPHEN HAWKING (1942—2018) gravitational waves (which would carry the telltale telescopes within 10 hours of the merger, placing the recent accelerated expansion of the Universe? These RAJESH GOPAKUMAR & SPENTA R. WADIA signature of the inspiral and merger of neutron event in the galaxy NGC4993. These observations are among questions upon which gravitational wave stars), gamma—rays and other radiation could settle also confirmed the formation of heavy elements detectors such as the Einstein Telescope and Cosmic Biographical Details th the matter. that was predicted more than five decades before. In Explorer, detector concepts that are currently being Stephen Hawking, born 8 January 1942, at Oxford total, more than 70 astronomical groups around the studied, could provide some insights. in an academic family had an early aptitude and August 17, 2017, just a little over a week before world followed up GW170817 and confirmed that inclination towards science. He studied physics the LIGO and Virgo detectors were shut down Acknowledgements the event produced x—rays, UV, optical, infrared and and chemistry at university in Oxford though he to commission further sensitivity improvements, I would like to thank my colleagues in the LIGO radio waves, just as astrophysicists had predicted seems not to have excelled as a student, instead finally saw the observation of a binary neutron star and Virgo Scientific Collaborations for many useful years before. spending much of his time at the college boat club! merger. This event literally shook the world. Dubbed discussions on gravitational waves and for Figures He went to Cambridge for his Ph.d. hoping to study GW170817, it is the loudest event recorded by our Not everything is hunky and dory. Many puzzles 2—4 used in this article. cosmology with Fred Hoyle but instead was assigned detectors so far and came from the merger of a pair remain: for a GRB that occurred so close, the to Dennis Sciama. It was at this time that he was Further Reading of neutron stars of masses roughly in the range1.2 intensity was far too weak, raising questions about diagnosed with ALS or Lou Gehrig’s disease — a 1. GW170817: Observation of Gravitational Waves and 1.6 solar masses. LIGO and Virgo localized the nature of the gamma—ray jet and the central degenerative motor neuronal disorder. Though he from a Binary Neutron Star Inspiral B. P. Abbott et the source to within 28 square degrees in the engine that produced it. The aftermath of the merger was given a couple of years to live at age 22 or so, his al. Phys. Rev. Lett. 119, no. 16, 161101 (2017) should have produced a highly oblate, bar—like object disease progressed slower than predicted. Hawking BETWEEN THE that also emits gravitational waves. This radiation 2. Observation of Gravitational Waves from a Binary overcame an initial depression to plunge fully is not expected to be strong but we do not know Black Hole Merger B. P. Abbott et al. Phys. Rev. into his research soon making a mark for himself, SCIENCE how weak that might have been and if it conforms Lett. 116, no. 6, 061102 (2016) winning the prestigious Adams Prize at the time of with theoretical predictions as no post—merger his thesis in 1966. He remained at Cambridge as a 3. Multi—messenger Observations of a Binary oscillations have been detected. We also do not know fellow of Gonville and Caius College for much of his PARAMESWARAN AJITH was named the Neutron Star Merger B. P. Abbott et al. Astrophys. how long the bar—shaped merger remnant lasted research career, except for a stint as the Sherman 2017 CIFAR Azrieli Global Scholar. He is the J. 848, no. 2, L12 (2017) as an unstable, hyper—massive neutron star, before Fairchild Distinguished Professor at Caltech from only Indian researcher among fifteen early collapsing to a black hole, assuming a black hole 4. Binary Black Hole Mergers in the first Advanced 1970 to 1975. He was elected at age 32 as a Fellow career researchers to receive this prestigious did eventually form. More sensitive detectors are LIGO Observing Run, B. P. Abbott et al. Phys. Rev. of the Royal Society of London and appointed in two—year appointment. required to resolve these and other questions such X 6, no. 4, 041015 (2016) 1979 to the celebrated Lucasian Professorship of as how stiff neutron stars are, their size compared to Mathematics (held by Newton, Babbage, Dirac ABHIRUP GHOSH received the Ramkrishna their mass and the composition of their cores. 5. The basic physics of the binary black hole merger and others) at Cambridge. He held this post till his Cowsik Medal of TIFR. This medal is GW150914, B. P. Abbott et al. Annalen Phys. 529 retirement in 2009. Despite a progressive loss of his given across the TIFR system for the best Future of Gravitational—Wave Astronomy (2017) motor abilities and being increasingly confined to his paper published in the last three years to In just two years since their first operation, Advanced wheelchair and later forced to communicate through researchers under the age of 35. Abhirup was LIGO and Advanced Virgo have made discoveries References a voice synthesiser, he maintained a remarkably awarded for his work on a test devised by him that have given us a wealth of new information 1 Proper distance between two bodies is the distance productive scientific career which continued with and collaborators, of Einstein’s general theory about dynamical spacetime. They have established a between them in a reference frame in which they are research publications almost till a few months before of relativity using the measurements of LIGO. new window for observing the Universe and begun both at rest. his demise on 14th March, 2018. to transform our understanding of the formation 2 In comparison, Newton’s laws of mechanics are RAMA GOVINDARAJAN was awarded the and evolution of black holes. When they reach their Below we first sketch the important scientific valid only in inertial frames; in non—inertial frames Platinum Jubilee Award of the Aerospace design sensitivity, LIGO and Virgo will routinely contributions by Hawking hoping to convey to one would need to add fictitious forces to get department of IISc. This is awarded to the observe the gravitational—wave sky and discover a broad scientific audience the path—breaking Newton’s laws to work. alumni of the department, who have made new processes and phenomena in the local Universe. nature of his discoveries. We also felt that a fuller significant contributions in the field. It is no surprise that 2017 Nobel Prize was awarded 3 The chirp mass Mc of a binary composed of masses understanding of his scientific legacy and in 3/5 –1/5 to the pioneers of this exciting new discovery. m1 and m2 is Mc = (m1 m2) (m1 + m2) . According particular, the lasting impact of his work is best SUVRAT RAJU was awarded the to general relativity the rate at which the signal’s brought out by placing it in the broader context of Even more sensitive detectors would be required Swarnajayanti Fellowship from the frequency increases depends predominantly on this current research on some of the questions that were to solve some of the most enigmatic questions in Department of Science and Technology combination of the component masses. at the heart of Hawking’s quest. fundamental physics, nuclear physics, astronomy (DST) to advance the research on and cosmology. What is the nature of highly ‘information paradox’. B.S. Sathyaparakash is an astrophysicist and a The Major Scientific Contributions of Hawking deformed horizons and are black holes the true 1 professor at Penn State University, USA & Cardiff In a foreword in 1993, to a collection of his papers , end states of gravitational collapse? What is the Hawking writes ‘With hindsight, it might appear that SPENTA WADIA was named the ICTS University, Cardiff, UK. ■ structure of neutron star cores and is there a there had been a grand and premeditated design Homi Bhabha Chair Professor of the Infosys state of stable matter beyond nucleons that can to address the outstanding problems concerning Foundation. hold out against gravitational collapse? When did the origin and evolution of the universe. But it was

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not really like that. I did not have a master plan; The work culminated in a very general result He also made an important contribution to the holes together with the entropy assigned to the rather I followed my nose and did whatever looked by Hawking and Penrose (1970), who showed, so—called ‘no hair theorem’, building on earlier black holes, is always non—decreasing. However, interesting and possible at the time.’ However, it is under very general conditions, that singularities work of Werner Israel and Brandon Carter. This Bekenstein did not have any reliable way to fix the very striking to see the coherence of ideas as well as are unavoidable (in either the past or the future) aimed to show that a black hole (in four dimensional constant of proportionality to the area. steady progression of thinking in Hawking's work. in solutions of Einstein equations. A crucial role spacetime) is completely characterised by its mass, Bekenstein’s proposal was strenuously opposed by Scientifically, the most productive period of his life in the proof was played by the Raychaudhuri charge and angular momentum (and not by more Hawking since assigning an entropy meant black was from the late sixties through the mid—late equation, derived more than a decade earlier, which detailed characteristics of the kind of matter that holes could also have a temperature and this was eighties, peaking with the remarkable discoveries demonstrated the focussing effect of gravity on went into forming it, for instance). Hawking’s result classically impossible since they could not emit of the mid—seventies that he is most celebrated matter which made the formation of singularities here on axisymmetric solutions being given by the radiation and only absorb it. During a Moscow visit for. In this section, we trace this remarkable inevitable. The use of a local energy condition Kerr metric helped, together with later work by in 1973, Hawking was influenced by the Soviet trajectory with broadbrush strokes. It begins with capturing the positivity of matter energy density David Robinson, to firm up this statement. But it astrophysicists, Ya. Zeldovich and Alexei Starobinsky, his fundamental work on singularities in the classical showed that the essentially attractive nature of was the area theorem which led Hawking, in work who had described a classical phenomenon called theory of general relativity in the sixties. This leads gravitation was ultimately what was responsible. The with Jim Bardeen and Brandon Carter, to further superradiance from rotating black holes and to pioneering work on general properties of black generality of the Hawking—Penrose result helped to formulate the ‘four laws of black hole mechanics’ in heuristically argued from the quantum uncertainty holes, at first in the classical theory, but eventually not only settle the controversy on singularities but analogy with the four laws of thermodynamics. The principle as giving rise to a similar phenomenon. incorporating quantum effects and raising the also highlighted the power of the new techniques of area theorem was the analogue, in this work, of the Hawking attempted to rigorously incorporate conundrums that have not been fully resolved to this global analysis that were brought to bear. second law of thermodynamics whereby entropy quantum effects in the background of a rotating day. monotonically increases. But there was also a first These continue to play an influential role in classical black hole. To his surprise he found a nontrivial law which in analogy with the thermodynamic law Realising that these effects might also be present in general relativity and the textbook by Hawking and spectrum of radiation even for a non—rotating ∆E = T∆S (in its simplest form without additional the early universe led to insights on how these small Ellis which approached the subject from this point of (Schwarzschild) black hole. Moreover, the spectrum potentials and work terms) read as fluctuations are eventually responsible for structure view is now a classic. was exactly thermal (with a Planckian distribution of formation at the largest scales. This, in turn, led ∆M = ∆A (1) the frequencies) with a temperature — the Hawking Shortly, thereafter, Hawking realised that the that such a cosmological event horizon can be Classical properties of black holes to wrestling with the really difficult problems of temperature perfectly thermal nature of black hole radiation also assigned an effective Hawking temperature (directly 휅 Given the generic nature of black holes and since the Here the mass of the black hole played the role of ħc3 quantum gravity i.e. the quantum fluctuations of T = created a further tension in the ability to have a proportional to the surface gravity k and h as before) tools now existed to address their general behaviour, thermodynamic energy while the surface gravity H 8πG Mk (2) spacetime itself. The striking proposals on the wave N B consistent quantum description of black holes. His as well as an entropy proportional to the area of the this is what Hawking next turned his attention onto. (measuring the acceleration due to gravity at function of the universe and related approaches to Here M is the mass of the black hole and the rest are observation was based on the fact that in quantum two dimensional surface (with the same constant of The focus, however, shifts now from the singularity the horizon of the black hole) played the role avoiding the singularities associated with the big 휅 fundamental constants such as the speed of light (c), mechanics a state with a thermal density of radiation proportionality as in the black hole case). This area is to the event horizon. The event horizon is one of the of temperature T (in addition, to the area being bang, while incomplete in themselves, ultimately Planck’s constant (ħ), Boltzmann’s constant k ) and is a mixed state (or density matrix) as opposed to a inversely proportional the value of the cosmological most enigmatic and perhaps (at least, in the popular like the entropy, as observed earlier. There is a B may well be embedded in a full edged understanding Newton’s constant of gravitation (G ). This beautiful pure state. constant parameter . This cosmological entropy imagination) defining feature of a black hole. It is straightforward generalisation to include additional N of quantum cosmology. formula for the temperature was proportional to can be viewed as a measure of the ignorance of the the region of spacetime which typically cloaks the work terms.). Moreover, was constant over However, the unitary time evolution of quantum Λ ( ∞ 1 ) as foreshadowed by the laws of observer to the degrees of freedom beyond her G M The singularity theorems black hole singularity and is entirely shielded from the entire horizon and this was like in the zeroth N mechanics (which is central to ensuring that the sum 휅 black hole mechanics but fixed the constant of horizon. Many of the known (and physically interesting) an external observer. This is because even light rays law of thermodynamics where the temperature 휅 of all quantum probabilities add up to one) prevents proportionality in terms of the Planck’s constant. exact solutions of Einstein equations possess what is are subject to the strongly focussing gravitational is a constant at equilibrium. Finally, there was an pure states from evolving into density matrices. When these ideas were put forward, de Sitter (dS) Thus it demonstrates the intrinsically quantum known as a singularity. This is a region of spacetime field within the event horizon and cannot escape analogue of the third law in that it is apparently There arises then a paradox of how a black hole spacetime was more of a historical toy example of nature of the phenomenon. beyond which the spacetime cannot be continued outside. By bringing his powerful techniques to bear impossible to reduce to zero for a black hole which can be formed from the collapse of matter a cosmological spacetime. It is rather remarkable because the curvature (which is a measure of the on the nature of the event horizon, Hawking was through a finite sequence of processes. However, in prepared in a pure state can evolve into a thermally that forty years later, dS spacetime is central to 휅 This immediately led, via the second law of black strength of the gravitational field) goes to infinity able to prove a number of results, striking in their their paper Hawking and others stressed this was hole mechanics, to the constant of proportionality radiating object. In fact, eventually a black hole can modern cosmology. With the discovery of a dark or ‘blows up’. Associated physical quantities like generality. He could show that in four spacetime only an analogy and that the actual temperature of in the entropy formula of Bekenstein to be fixed— to completely evaporate leaving only the radiation energy component and current day acceleration, the density and pressure also blow up. This is also a dimensions, the two dimensional surface which a black hole was zero since it could absorb radiation be what is now called the Bekenstein—Hawking behind. This puzzle about which we will have more Universe is expected to approach de Sitter spacetime signal of the breakdown of predictability of the defines the event horizon at any given slice of time but not emit anything. formula to say in the next section is called the ‘Information in the future as galaxies dilute away in the expansion. A classical Einsteinian description. The solutions which always has the topology of a sphere. He was further S = k (3) Paradox’ and continues to be actively debated to the Moreover, the initial phase of the universe is believed Quantum Properties of Black Holes BH B 4G ħc3 exhibit such behavior include the Robertson—Walker able to show that the area of this surface, no matter N present day. to have had a period of exponential expansion known Jakob Bekenstein, on the other hand, took seriously metric for describing the expanding universe, the how complicated, must always increase (with as inflation, whose signals have been measured the observation that black holes can apparently Thus Hawking showed that Bekenstein’s proposal Schwarschild and Kerr solutions for describing time) if the matter obeyed the positivity of energy Quantum effects in cosmological spacetimes did make sense if quantum effects were taken in the tiny anisotropies of the cosmic microwave violate the second law of thermodynamics since Hawking, together with Gary Gibbons, realised in spherically symmetric and rotating black holes, conditions mentioned above. This is what is often background radiation that bathes us all. Thus there one can throw a cup of hot tea into the black hole into account. Classically a black hole appears respectively etc. In the sixties there was a dominant referred to as the area theorem. As we will see this 1977 that certain cosmological spacetimes which to be featureless and black but it actually has a is good reason to believe that the very early universe and its entropy disappears from the rest of the have an exponentially accelerated expansion (known school of thinking which felt these singularities were will play a central role in the developments to follow. was also described by a dS spacetime! universe while the black hole being a unique object quantum mechanical entropy and a resultant black artifacts of highly symmetric solutions which would Incidentally, Hawking also has a paper from that as de Sitter (dS) spacetimes) also exhibit features (the ‘no hair theorem’) cannot carry any entropy body spectrum of radiation. This underscores the not be present in more generic, realistic cases. time in which he uses this theorem to put an upper similar to the thermodynamics of black holes. The Thus when inflation was proposed in the early (either before or after the cup of tea was thrown centrality of quantum mechanics in deciphering the However, in a series of papers, Roger Penrose, limit on the efficiency of conversion of mass into important similarity to the black hole case is the 1980s, Hawking was one of the first (together with into it). Taking inspiration from the Hawking area nature of black holes. Hawking’s calculation opened employing novel mathematical techniques began gravitational radiation, when two black holes collide, presence of an event horizon, now associated to Vyatcheslav Mukhanov and others) to realize that theorem he proposed that black holes do have a portal onto the quantum behaviour of gravity. We to question this dogma at least in the context of to be ( 1 – 1 ) or about 30 per cent. In the light of a given observer. An observer in a dS spacetime is quantum fluctuations in dS spacetime could be √2 a thermodynamic entropy proportional to the flesh out the significance and further developments black holes formed from collapsing matter. Hawking the recently measured collision of black holes by the only able to see a part of the spacetime even if she important. He realized that the scalar field which area. He proposed a generalised second law of of this crucial insight in the following section since (together with George Ellis, initially) tried to adapt LIGO instrument, this is no longer such an abstract waits infinitely long since the enormous acceleration was believed to drive the inflationary expansion thermodynamics in which the total entropy, namely, it also played an important role in the evolution of these to the cosmological setting. theoretical calculation (the observed efficiency was takes regions of spacetime out of causal contact could give rise to quantum fluctuations that would the usual thermodynamic entropy external to black Hawking’s thinking. only about 5 per cent)! with her. What Gibbons and Hawking realised was give the right level of inhomogeneity to be the origin

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Quantum theory and Einstein gravity Thus we will not describe the string theory answer As we have discussed earlier, the inevitability of to the first question but concentrate instead on the focusing singularities that indicate a break—down of second question4. General Relativity. In particular, the past singularity String Theory Microstates, Black Hole Entropy and raises fundamental questions about the notion of Hawking Radiation space—time in the initial instants at the birth of the In order to see how string theory addresses this universe. How would these singularities be resolved question we turn to an analogy to help explain in a quantum theory? We have also discussed his the basic point. Consider a fluid like water which work on the relativistic quantum field theory of is described by the dissipative Navier—Stokes elementary particles in the presence of a black hole equations. This description is essentially in terms that led to the notion of thermodynamic entropy of a smoothly evolving velocity field of the fluid. It for black holes and the ‘information paradox’. In is one of the great discoveries of science (from the deriving both these results the gravitational field 20th century) that underlying this continuum (field) (i.e. the metric of spacetime) was treated classically. description of the fluid are microscopic interacting However a complete theory would also require a molecules obeying the laws of quantum mechanics, consistent quantum treatment of gravity as well. and that the thermodynamic entropy of the system In fact, there can be no statistical mechanical can, in principle, be calculated using Boltzmanns

accounting of the black hole entropy without such formula S = kB log Ω where Ω stands for the number a microscopic quantum description of gravity. The of microstates. program to quantize gravity using the Einstein— We need the quantum mechanics of atoms Hilbert action as a starting point began in the early of all the large—scale structures we observe today in capping—off the geometries in the past–like and molecules to properly account for the They demonstrated that the Boltzmann entropy of give technically tractable models in which the 1960s 2 and references therein. Just as a photon is a the clustering of galaxies. replacing a conical tip by a spherical cap. This would thermodynamics of water! Returning to black this system is identical to the Hawking—Bekenstein ‘information puzzle’ can be directly addressed. [5] quantum of the electromagnetic field, the graviton, a lead to a particular ‘wave function of the universe’, holes we could ask: Are there quantum microstates entropy, including the precise proportionality factor Towards a Quantum Understanding of Gravity massless spin two particle, was viewed as a quantum which weights the various geometries at future times in string theory which would account for the that Hawking had derived. This demonstrated for the Quantum Gravity as a Quantum Field Theory: The The problem of addressing the quantum fluctuations of the gravitational field. The strength of the (now in Minkowski signature). Bekenstein—Hawking entropy upon using first time that black holes are composed of micro— AdS—CFT Correspondence of the gravitational field, i.e. spacetime itself, is a emission and absorption of gravitons is characterized Boltzmanns formula? states that are not contained in Einstein’s theory of A much more comprehensive view of the microstate notoriously difficult one, as we briefly explain in While very original, the parallels between non— by the dimensionless ratio E , where E is the E 1 General Relativity. The latter appears as a mean field counting of black hole entropy was enabled by pl ħc5 2 the next section. Hawking tried to develop his own Abelian theory and gravity do not quite hold at the typical energy of the gravitons and E = 19 pl ~10 String theory microstates: In 1995 Joseph Polchinski GN description of the physics of the micro—states in the insight of the AdS/CFT correspondence of approach to this question in full realization that it path integral level. Unlike non—Abelian theories, GeV. This says that at energies E~E or equivalently pl (building on earlier work by Jin Dai, Rob Leigh terms of a metric field, much as in the Navier—Stokes Maldacena in 1997. This relates all quantum was not complete or perhaps even fully consistent. the action for gravitational configurations can take time intervals t ~1048 secs, quantum fluctuations pl and Joe Polchinski, as well as Petr Horava) gave analogy. gravitational phenomena in asymptotically Anti de The ideas proposed by him and his collaborators arbitrarily large negative values. This is associated of spacetime are so large that the theory breaks δ a precise understanding of a class of nontrivial Sitter (AdS) space—times (with the opposite sign of have nevertheless been influential. In some ways, with the overall size factor of the metric. This makes down. Unlike the case of electromagnetism where Hawking radiation: Extremal black holes do not classical solutions, now called D(irichlet) p—branes, the cosmological constant from the dS spacetimes Hawking was guided by the, then recent, successful the sum over the configurations much less well quantum mechanics regulates the singular behaviour Hawking radiate. But the Hawking radiation of a in superstring theory. These are special types of mentioned earlier) holographically through a application of non—perturbative techniques to defined in gravity. Nevertheless the no—boundary of the 1=r coulomb potential, in gravity this does not ‘near extremal’ black hole could be microscopically domain walls, carrying generalised electric/magnetic unitary non—Abelian theory on the boundary of studying quantum field theories, like non—Abelian proposal and similar ideas in quantum cosmology may happen! modelled by in terms of a slightly excited D1—D5 charges, and of spatial dimension between 0 (points) the spacetime. Thus spacetime emerges due to the theories (which are at the base of the standard have a role to play as a semi—classical approximation and 9, labelled by p. These domain walls are the system coupled to gravitons by Avinash Dhar, Furthermore, such a quantum field theoretic strongly coupled and highly entangled quantum model that describes all the forces of nature other to a more fundamental description. end points of open strings, with their oscillations Gautam Mandal and Spenta Wadia, as also Sumit approach to gravity could not give the unusual area field theory on the boundary — a remarkable new than gravity). This was based on the path integral and interactions described by the emission and Das and Samir Mathur, Curt Callan and Andy Addressing the Puzzles of Black Holes and dependence (as opposed to the extensive, volume conceptual paradigm in physics! In particular, it or Feynman approach to quantum theory. Here absorption of open strings. At low energies these Strominger. After some effort the statistical formulas Quantum Gravity dependence) of the black hole entropy on its size means that the ‘mean field’ description of many one sums over all possible configurations (‘paths’), for Hawking radiation rates agree with those derived are described by non—Abelian gauge fields (of the (all?) strongly coupled quantum field theories is the is Hawking’s work on the quantum aspects of (as measured by the extent of event horizon). each weighted by a phase factor e h where S is same variety that appear in the standard model of from general relativity, including details such as black holes gave a very quantitative target, for Thus a simple minded quantization of matter gravitational field that lives in one higher dimension. the so—called action of the configuration. Many elementary particles). At the same time they are the grey body factor. Hence in a toy model of black physicists trying to understand the quantum nature and gravity runs into seemingly insurmountable This correspondence in now 20 years old and is still of the nonperturbative effects in non—Abelian massive and source gravity. In summary, D—branes holes in superstring theory the information paradox of gravity, to aim for: come up with a complete problems. The question then arises whether there is a beacon in our search for the complete theory of theories were uncovered by considering a so called are heavy, gravitationally interacting objects but presented in Hawking’s 1975 paper could be analysed and mathematically consistent theory which can a more fundamental theory that (1) is valid at E~E quantum gravity. It gives a concrete case study of a ‘Euclidean’ theory in which time is taken to be pl whose dynamics can be described by non—Abelian in all detail. It is important to emphasise that the microscopically account for the Bekenstein—Hawking and whose low energy ( E 1) limit is Einstein’s non—perturbative theory of quantum gravity in a imaginary and therefore the above weighting factor E above result could be derived in the favourable pl gauge fields. This crucial observation underlies large class of spacetimes. —s entropy of black holes. This had a profound impact theory and (2) is rich enough to account for all the actually becomes e h. ≪ the microscopic accounting of black hole entropy circumstance where the black hole is a bound state on the development of string theory, a framework of microstates that can explain black hole entropy and in string theory and the more general AdS/CFT of D—branes. For example the discussion does not In this concrete setting, phenomena like black hole Hawking advocated a similar Euclidean approach theoretical physics that has many of the ingredients Hawking radiation consistent with the principles of correspondence outlined in the next section. apply to a Schwarzschild black hole. But at the same evaporation obey the rules of quantum mechanics. to quantum gravity involving now a sum over all of being a quantum theory of gravity and achieved quantum statistical mechanics? The answer to both time it should be stressed that geometrically these Thus, in principle, the information loss puzzle for (Euclidean signature) metric configurations. One of a measure of success towards understanding the these questions is yes in the sense we explain below. Bekenstein—Hawking Entropy = Boltzmann black holes are not much different from the charged black holes in AdS spacetimes has a resolution. This the intentions was to bypass the issue of singularities questions raised by Hawking’s work. We summarize Whether this framework of string theory is indeed Entropy: This was the basis for the landmark paper cousins of Schwarzschild black holes. Also these are is what led Hawking in 2004 to concede that he that arises in the classical theory. To this end he this narrative below to give a glimpse of how what nature chooses is something that remains in 1996 of Andrew Strominger and Cumrun Vafa. not isolated examples and there is a plethora of such was wrong regarding the breakdown of quantum made the ‘no—boundary’ proposal with Jim Hartle, Hawking’s ideas have developed in contemporary to be established but the very fact that there is a They considered a particular (extremal) black hole solutions for which the Strominger—Vafa calculation mechanics in the presence of a black hole. However, which essentially mentions that one should sum over physics. consistent framework which is able to address both solution in type IIB string theory and showed that it has been generalised to with amazing success. It the question remains to pinpoint how exactly all Euclidean configurations which are smooth at the the above questions makes it compelling to consider can be viewed as a bound state of D1 and D5 branes. is also important to note that is these examples Hawking’s arguments, made within the framework putative singularity. In a sense, they were smoothly and sheds considerable light on Hawking’s results.

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of real fermions with disorder. This shows how the by mankind was genuinely inspirational. He followed Science Special Section: TWAS Science Frontiers, Vol Rajesh Gopakumar is a theoretical physicist and physics of black hole entropy imply certain universal up the success of his bestseller with a number of 95, No. 9, p. 1253—1267, 2008; arXiv:0809:1036 director of ICTS. characteristics for down to earth physical systems! other books which updated and elaborated on The 4 String theory and the conundrums of quantum Spenta Wadia is a theoretical physicist and the Brief History of Time. A very engaging series of Hawking’s visit to India gravity, Rajesh Gopakumar Current Science, Vol. 109, founding director of ICTS. books aimed at sparking the interest of children Hawking visited India on the occasion of the Strings No. 12, p. 2265—2270, (2015) in science was co—authored with his daughter This article was originally written for Current Science, 2001 meeting that was held at the Mumbai campus Lucy Hawking. In addition, the large number of 5 Microscopic formulation of black holes in string Vol. 114, No. 7, 10 April 2018. of TIFR. It was the first meeting of this series to documentaries on his science and work as well as theory, J. R. David, G. Mandal and S.R. Wadia, hep— All images are from Stephen Hawking's visit to India be held outside of North America and Western the Hollywood film ‘The Theory of Everything’ made th/0203048, Phys. Rept. 369, 549 (2002) in 2001, courtesy of Tata Institute of Fundamental Europe and it was an international recognition of the him the universally recognisable face of theoretical Research (TIFR), Mumbai. ■ contribution to string theory from 6 physics. It is clear that his story will continue to From AdS / CFT correspondence to hydrodynamics, Giuseppe Policastro, Dam T. Son, Andrei O. Starinets, India. He participated in this meeting as an invited inspire many future generations to dedicate their JHEP 0209 (2002) 043, hep—th/0205052 speaker together with other eminent scientists like lives to the quest to answer the mysteries of the David Gross and Edward Witten. universe. 7 The fluid/gravity correspondence, Veronika E. Hubeny, Shiraz Minwalla, Mukund Rangamani, [hep— Hawking very much had a zest for life. During the References 1 th] arXiv:1107.5780, Conference: C10—06—01.1, conference banquet we celebrated his 59th birthday Hawking on Big Bang and Black Holes, Stephen p.817—860 Proceedings and he danced with his wife — swirling his chair Hawking, Advanced Series in Astrophysics and around and back and forth. A vivid memory of his Cosmology—vol 8, World Scientific, 1993 8 Holographic Entanglement Entropy, Mukund visit is the warmth and care he showed towards 2 One—loop divergences in the theory of gravitation, Rangamani, Tadashi Takayanagi, [hep—th] the many, many people from all walks of life who G. ’t Hooft and T. Veltman, Ann. Inst. Henri Poincare, arXiv:1609.01287, Published in Lect.Notes Phys. 931 met him. Children from TIFR’s housing colony had a Vol. XX, no. 1, 1974, p 69—94. (2017) pp.1—246 of the mean field theory of Einstein equations, break to show the positivity of the entropy current in uid meeting with him, which was so inspiring for them. 7 9 A bound on chaos, Juan Maldacena, Stephen H. down. Probing deeper has led to an investigations dynamics . Hawking’s visit to India was made possible by Mr S. 3 String Theory: A framework for quantum gravity of quantum entanglement and non—locality in and various applications, Spenta R. Wadia, Current Shenker, Douglas Stanford, [hep—th] JHEP 1608  A formula for quantum entanglement entropy of D. Shibulal of Infosys Technologies, an alumnus of quantum gravity, and the correspondence of degrees (2016) 106, arXiv:1503.01409 a region A in a strongly coupled field theory was TIFR. He so generously and so promptly agreed to of freedom inside and outside the horizon of a black pay for the expenses involved in bringing Hawking 3, 4 proposed by the Ryu—Takayanagi, hole. to India. Without this it would not have been for Area (γ ) S = A Hawking to travel to India as many other potential Hawking’s work and non—gravitational physics A (5) 4ħGN AdS—CFT correspondence displays the power of the donors from Mumbai did not come forward. Anand string theory framework in unifying diverse physical where Area(A) is the minimum area surface Mahindra provided a special vehicle for Stephen. (co—dimension two) A in AdS space—time, whose phenomena. We list in the following a few remarkable One important outcome of Hawking’s visit was that boundary is the same as that of the region A. formulas of strongly coupled quantum systems science and its mysteries were in the public eye Even though the form is superficially that of the that follow from this correspondence. In all of them for a week or more. His visit also helped highlight Bekenstein—Hawking form, there needs to be no Hawking’s results play a central role and powerfully the string theory contribution from India, in India. horizon and or even a black hole. It exhibits a deep demonstrates how far—reaching and profound Hawking’s presence in the country was quite a connection between quantum information theory their impact has been – even on physics which have sensation and the media was in full swing about him, and Hawking’s formula8. apparently little to do with gravity. including joining him for a walk along Marine drive.  A universal form for the ratio of viscosity to the  Black holes scramble information most efficiently. R. K. Laxman’s cartoon of Hawking appeared in the entropy density of a strongly interacting relativistic In the quantum field theory this corresponds to Times of India; Hawking also gave a public lecture at fluid is obtained by perturbing a static black hole the ‘buttery effect’ that describes how a small the Shanmukhananda Hall in north Mumbai and the by an in—falling wave. In the boundary field theory disturbance in the far past spreads through the huge hall was filled to capacity! this generalises thermodynamics to dissipative system characterised by an exponential growth e t. Hawking and Science Popularisation The exponent λ is the analogue of the Lyapunov λ hydrodynamics, and AdS—CFT relates the viscosity Hawking was indeed a great global ambassador for to the absorption cross section (at zero frequency) exponent for many body systems and it is most fundamental science. Through The Brief History of of the wave incident on the black hole, easily calculated in the gravity theory to be, Time and subsequent popular science works and A ħ = abs = = (4) λ = Ҡ (6) public engagements, Hawking was able to create a s 16πG s 16πG s 4πk � � N N B worldwide connect with the cosmic questions that where Ҡ = 2πk T is the surface gravity and T is the In the above we have used the Bekenstein—Hawking B physicists wrestle with. His book sold more than temperature of the black hole. This inspired the entropy formula. This has proved very influential in ten million copies and was translated into over 40 proof thatҠ = 2πk T is the maximum value (‘chaos understanding the physics of the strongly interacting B languages. He was easily the most well—known bound’) of such an exponent in a unitary quark—gluon plasma [6]. These ideas led to a precise living scientist for the general public for more than two decades. His life story of a brilliant mind trapped derivation of relativistic hydrodynamics and transport quantum system 9. An example of a quantum in a failing body and yet able to transcend these coefficients from the Einstein equations in AdS, and mechanical system that has a maximum value of limitations to do creative work of the highest order also to the discovery of new terms in superfluidity. the exponent λ is the Sachdev—Ye—Kitaev model Another application was to use the area theorems on some of the most fundamental questions asked

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Turbulence from Angstroms to Light Years S. Chandrasekhar’s fluid dynamics Stephen Hawking's Legacy in Fundamental Kavli Asian Winter School on Living matter KAAPI WITH KURIOSITY Strings, PROGRAMS This program is aimed at Master's– and PhD–level students who wish to be SPEAKERS Particles exposed to interesting problems in biology that lie at the biology-physics Claudia Bank, Instituto Gulbenkian de Ciência, Oeiras URBASI SINHA is an associate professor at the interface. Besides familiarity with basic biology, they will be expected to have an Ramray Bhat, Indian Institute of Science, Bangalore Light and Matter Physics group at the Raman Research Institute in adequate background in physics and/or mathematics. The school will consist of Bengaluru, India. She joined RRI in 2012 and is now heading the Quantum and Cosmology 20 January 2018 to 25 January 2018 ✦ Organizers — 22 January 2018 ✦ Speaker — Anne-Florence Bitbol, Université Pierre-et-Marie-Curie, Paris Katepalli Raju Physics formal lectures as well as informal tutorial sessions. Information and Computing (QuIC) laboratory at RRI. The lab specializes Albert Goldbeter, Université Libre de Bruxelles, Brussels in experiments on quantum information processing including quantum Olivier Hamant, École normale supérieure, Lyon computing and quantum communication, primarily using single and The topics to be covered in the lectures are based on these themes and can be Sandeep Krishna, NCBS–TIFR, Bangalore Kaapi with Kuriosity is a monthly 2018 entangled photons. She is also an associate faculty member at the Institute outlined in terms of four questions: public lecture series organised The Kavli Asian Winter School (KAWS) The Kavli Asian Winter School 2018 will Vijaykumar Krishnamurthy, ICTS–TIFR, Bangalore for Quantum Computing (IQC), University of Waterloo, Canada, and the by the International Centre for on Strings, Particles and Cosmology focus on the following topics (a) Do physical constraints impede or favour the adaptation of evolving systems? Sunil Laxman, InSTEM, Bangalore Centre for Quantum Information and Quantum Control, University of Theoretical Sciences (ICTS–TIFR), is a pan-Asian collaborative effort of (b) To what extent can evolutionary outcomes be explained in terms of the Subramony Mahadevan, Indian Institute of Science, Bangalore Toronto, Canada. One of her noted pieces of work was a novel in collaboration with the high energy theorists from China, Conformal Bootstrap short–term behaviour of physical systems? Vidyanand Nanjundiah, Centre for Human Genetics, Bangalore experimental test of the Born rule for probabilities in Quantum Mechanics. Jawaharlal Nehru Planetarium India, Japan and Korea to give young Luis Alday (Univ. of Oxford) ✦ (c) How may mathematical models help in understanding fundamental principles Utpal Nath, Indian Institute of Science, Bangalore and (Dean of NYU Tandon School of 24 April 2018 Speaker — and other educational researchers in Asia an opportunity Cosmology Rama Govindarajan Shravan Hanasoge Sreenivasan Rajesh Gopakumar Stuart Newman, New York Medical College, Valhalla of spatio–temporal organisation in living systems? In recognition of her scientific achievements as well as outreach activities, institutions in Bengaluru. to come together and learn about the Nima Arkani-Hamed (IAS) (d) Can quantitative experiments and large–scale data provide new conceptual Clément Nizak, ESPCI Paris she was awarded the Homi Bhabha Fellowship in the year 2017 and has latest developments in high energy Scattering Amplitudes insights on living matter? Andràs Paldi, École pratique des hautes études, Paris most recently been named the recipient of the 2018 ICTP-ICO Gallieno theory, from leading experts on the Freddy Cachazo (PITP) Abdur Rahaman, NISER, Bhubaneswar ictstifr Denardo Award in Optics. subject. Supersymmetric gauge theories These questions will be illustrated in a range of contexts from molecular Olivier Rivoire CIRB, Collège de France, Paris Dates Shiraz Minwalla (TIFR) evolution to ecology through cell and tissue dynamics. Ramanujam Srinivasan, NISER, Bhubaneswar 08 January to This school is aimed towards advanced ictstifr Bulk reconstruction Zorana Zeravcic, ESPCI Paris 18 January, 2018 graduate students, postdoctoral fellows and active researchers in the field. Kyriakos Papadodimas (CERN) ✦ ICTStalks Living Matter Engineering; The Eugene Kleiner Professor for (ICTS-TIFR) Venue — Infosys Campus, Electronic SYK Model ORGANIZERS Venue This is the 12th in a series of Asian Vladimir Rosenhaus (KITP) Vidyanand Nanjundiah Ramanujan Lecture Hall, 16 – 26 April, 2018 icts.res.in/outreach Winter Schools that have been + A special lecture by David Gross (KITP) Olivier Rivoire ICTS Bangalore FASCINATING WORLD organized on a rotating basis between QFT dynamics in 2+1 dimensions CONTACT US China, Japan, Korea and India. We Nathan Seiberg (IAS) [email protected] Registration deadline Ramanujan Lecture Hall, [email protected] welcome students from all of these ICTS at Ten OF PHOTONS, 15 September 2017 String Field Theory participating countries as well as Ashoke Sen (HRI) PROGRAM LINK 080 6730 6000 students from outside. ✦ ICTS, Bengaluru www.icts.res.in/program/LivingMatter2018 SUPERPOSITION Contact us 16—26 April 2018 Organizers — Steering Committee Vidyanand Innovation in Mechanical Engineering; Professor of City, Bangalore [email protected] All outstation participants who get Bin Chen (PKU) & ENTANGLEMENT selected will be provided REGISTER ONLINE Rajesh Gopakumar (ICTS-TIFR) accommodation. Limited travel Program link Koji Hashimoto (Osaka Univ.) Quantum mechanics is a cornerstone of modern physics. https://www.icts.res.in/ support is available on request th Yoshihisa Kitazawa (KEK) Just as the 19 century was called the Machine Age and program/KAWS2018 Bum-Hoon Lee (Sogang Univ.) ✦ The 2018 School is generously 4—6 January 2018 Organizers — Rajesh the 20th century the Information Age, the 21st century Kimyeong Lee (KIAS) Organizers supported by the Kavli foundation. promises to go down in history as the Quantum Age. Miao Li (ITP-CAS & Sun Yat-Sen Univ.) Minxin Huang It is also partially supported by funds Jianxin Lu (Univ. of Sc. & Tech) In this talk, I will discuss key properties of quantum Sangmin Lee from Infosys foundation. Nanjundiah and Olivier Rivoire www.icts.res.in/outreach/registerwww.bit.ly/2DOeZGc systems called Quantum Superposition and Quantum Soonkeon Nam (Kyung Hee Univ.) Physics (Faculty of Arts and Science); Mathematics Sungjay Lee Entanglement. I will discuss the world of single and Hirosi Ooguri (Caltech & Kavli IPMU) Loganayagam R Advisory Board Ashoke Sen (HRI) entangled photons and also discuss ongoing work towards Suvrat Raju David Gross (KITP) Sang Jin Sin (Hanyang Univ.) quantum technology in our Quantum Information and Tadashi Takayanagi Andrew Strominger (Harvard Univ.) Spenta Wadia (ICTS-TIFR) When & where Computing lab at the Raman Research Institute, Bengaluru. Masahito Yamazaki Hirotaka Sugawara (OIST) Gopakumar and Spenta R. Wadia VISHVESHWARA LECTURES 4 pm, Sunday, Gang Yang Shing-Tung Yau (Harvard Univ.) 2125stth January,February, 2018 2018 (Courant Institute of Mathematical Sciences)) J. N.Planetarium, Sri T. Chowdaiah Road, High Grounds, Bangalore – 560 001

Image: Simulation of fossil limb skeletons. Third Bangalore School on Population ICTS has introduced a new lecture series, celebrating Stuart Newman et al. All are welcome. From left to right – Brachypterigius, Sauripterus, Eusthenopteron, Panderichthys Algorithms and Optimization INTERNATIONALINTERNATIONAL CENTRE CENTRE FOR FOR THEORETICAL THEORETICAL SCIENCES,TATA SCIENCES,TATA INSTITUTEINSTITUTE OF OF FUNDAMENTAL FUNDAMENTAL RESEARCH, RESEARCH, SHIVAKOTE, SHIVAKOTE, HESARAGHATTA HESARAGHATTA HOBLI, HOBLI, BENGALURU BENGALURU 560089 560089 ICTS at Ten Genetics and Evolution Symmetries, Duality, and the Unity of Physics the life and work of C.V. Vishveshwara – a pioneer in Celebrating the unity of Science ICTS at Ten ✦ Celebrating the unity of Science ✦ 2—3 January 2018 Organizers — Prateek Jain and 5—17 March 2018 Organizers — Deepa Agashe 8 January 2018 ✦ Speaker — Nathan Seiberg black hole physics and science outreach in India. The KAAPI WITH KURIOSITY PRESSING FOR Indian Statistical Physics

Nisheeth K. Vishnoi Participation is invited for the ICTS discussion Dates PROGRESS Community Meeting 2018 meeting ‘Turbulence - from Angstroms to 20 January, 2018 to and Light Years’. Students and postdocs are 25 January, 2018 Kavita Jain (Institute for Advanced Study, School of Natural Vishveshwara Lectures will be delivered by leading A DISCUSSION MEETING specially encouraged to apply. This is an annual discussion meeting of the Indian statistical physics community which is attended Venue Kaapi with Kuriosity is a monthly by scientists, postdoctoral fellows, and graduate students, from across the country, working in the The topics covered – ICTS Bangalore ON THE GENDER GAP IN broad area of statistical physics. public lecture series organised Basic turbulence by the International Centre for Isotropic and homogeneous turbulence Registration deadline PHYSICS This meeting would be the 5th in this series of meetings. This meeting will cover all the 8 Topics Quantum turbulence 20 October, 2017 Theoretical Sciences (ICTS–TIFR), covered at STATPHYS meetings, namely � in collaboration with the Cosmological turbulence Jawaharlal Nehru Planetarium General and mathematical aspects Boundary layers and lab flows Contact us and other educational Rigorous results, exact solutions, probability theory, stochastic field theory, phase transitions and Geophysical and astrophysical flows [email protected] Science is supposed to be an activity open to all This program is the kick-off event of the newly critical phenomena at equilibrium, information theory, optimization, etc. Sciences, Princeton, New Jersey, USA) scientists who have also contributed greatly to institutions in Bengaluru. people, regardless of their gender (or, for that constituted Gender in Physics Working Group of Out-of-equilibrium aspects Among the speakers are – If you work in this area, Statistical Physics Methods in Machine matter, their class, ethnicity or caste). However, the Indian Physics Association. Driven systems, transport theory, relaxation and response dynamics, random processes, anomalous H. M. Antia, TIFR, Mumbai kindly visit the program diffusion, fluctuation theorems, large deviations, out-of-equilibrium phase transitions, etc. page at – ictstifr the practice of science today across the globe falls Jaywant H. Arakeri, IISc Quantum fluids and condensed matter https://www.icts.res.in/ short of this ideal. The disparity between men and The discussion meeting is aimed primarily at Nonperturbative and Numerical Approaches Strongly correlated electrons, cold atoms, graphene, mesoscopic quantum phenomena, fractional Carlo F. Barenghi, Newcastle University discussion-meeting/taly2018 ictstifr women in the profession is high, especially in the physics researchers, teachers and other physics quantum Hall effect, low dimensional quantum field theory, quantum phase transition s, quantum information, entanglement, Lüttinger liquid, spin liquid, etc. Eberhard Bodenschatz, Max Planck Institute physics discipline, both in India and world-wide. professionals, as well as students of physics at Disordered and glassy systems Arnab Rai Choudhuri, IISc ICTStalks the college level and above, but is open to all Percolation, spin glasses, structural glasses, metallic glasses, jamming, glass transition, Ratul Dasgupta, IIT Bombay communicating science to the public. This discussion meeting will address the following interested audiences. algorithmic problems, etc. icts.res.in/outreach Enrico Fonda, New York University Learning questions: Biological physics Speakers/Panelists Molecular motors, single and multicellular dynamics, bacteria, swimmers, spatio-temporal Najmeh Foroozani, ICTP [email protected] ✿ What is the nature and extent of gender inequity organization, biological membranes, biopolymer folding, genomics, biological networks, Rama Govindarajan Dinakar Kanjilal Prajval evolution models, evolutionary game theory, etc. Laurent Gizon, Max Planck Institute in the physics profession? Katepalli to Quantum Gravity, String Theory and Shastri Vandana Nanal Resmi Lekshmi Soft matter Rama Govindarajan, ICTS 080 6730 6000 ✿ Sreenivasan INFOSYS—ICTS DISTINGUISHED image - Ute Kraus (Wikipedia) Background Why should practicing physicists care? Suchetana Chatterjee Suratna Das Tanusri Simple and complex fluids, active matter, molecular and ionic fluids,wetting, self-assembly, Shravan Hanasoge, TIFR, Mumbai will deliver the ✿ What has been done so far? polymers, gels, liquid crystals, microemulsions, foams, membranes, colloids, granular materials, etc. Infosys – ICTS Saha-Dasgupta Srubabati Goswami Anitha Daniel Lathrop, University of Maryland ✿ What is the way forward? Nonlinear physics Subrahmanyan REGISTER ONLINE Kurup Maitri Gopalakrishna Rohini Godbole Dynamical systems, chaos (classical and quantum), pattern formation, chemical reactions, Sanjiva Lele, Stanford University Chandrasekhar hydrodynamic instabilities, turbulence (classical and quantum), etc. lectures over three ✦ Shobhana Narasimhan Bindu Bambah Manikandan Mathur, IIT Madras 26—30 December 2017 Organizers — The outcomes from the International Conference evenings. We will Mikhail Interdisciplinary and complex systems Sulabha Kulkarni Neelima Gupte Shubashree also host a on Women in Physics 2017, organised by the Networks and graphs, epidemics, econophysics, social phenomena, traffic flow, ecology, etc. Eckart Meiburg, UC Santa Barbara Desikan felicitation session International Union of Pure & Applied Physics, will Charles Meneveau, Johns Hopkins University to celebrate Prof. Sreenivasan's Holography be presented. The planned global gender gap survey ORGANISERS Roddam Narasimha, JNCASR LECTURES Exploring the Universe with Gravitational contributions Gender in Physics Working Group of the IPA Ranjini Bandyopadhyay, Abhishek Dhar, Kavita Jain, Rahul Pandit, by the International Science Council, and Joe Niemela, ICTP to science. Suchetana Chatterjee Srubabati Goswami Sanjib Sabhapandit, Samriddhi Sankar Ray, Prerna Sharma www.bit.ly/kwk2018jan addressing sexual harassment in the workplace will Rahul Pandit, IISc Resmi Lekshmi Vandana Nanal Tanusri also be discussed. Saha-Dasgupta Prajval Shastri (Chair) O. N. Ramesh, IISc Belkin, Chandan Dasgupta, Partha Mitra and Rina RAMESH NARAYAN 16 February – 18 February, 2018 Samriddhi Sankar Ray, ICTS When & where A. Sameen, IIT Madras ✦ Joerg Schumacher, TU Ilmenau 27 January—3 February 2018 Organizers — 4 pm, Sunday, Ramesh Narayan is one of world's foremost experts on astrophysical Ramanujan Lecture Hall Poul st black holes. He is currently Thomas Dudley Cabot Professor of the Ladislav Skrbek, Charles University Mysteries Of The Higgs Boson Waves — From the Big Bang to Black Holes 21 January, 2018 Natural Sciences at Harvard University and Senior Astronomer at the ICTS, Bangalore Mahendra K. Verma, IIT Kanpur J. N.Planetarium, Smithsonian Astrophysical Observatory. In his long and illustrious Sri T. Chowdaiah Road, research career, he has made important contributions to a variety of areas John Wettlaufer, Yale University in astrophysics, including gravitational lensing, accretion disks, radio pulsars P. K. Yeung, Georgia Institute of Technology High Grounds, and gamma–ray bursts, apart from black holes. Narayan is elected Fellow Panigrahy Bangalore – 560 001 of many international societies, including the Royal Society, the American [email protected]  www.icts.res.in/discussion-meeting/ispcm2018 Association for the Advancement of Science, the World Academy of All are welcome. Sciences, the U. S. National Academy of Sciences and the Indian Academy H. Damgaard, Masanori Hanada, Anosh Joseph, 17 April 2018 ✦ Speaker — Michael E. Peskin 11 January 2018 ✦ Speaker — Kip S Thorne of Sciences.

INTERNATIONAL CENTRE FOR THEORETICAL SCIENCES,TATA INSTITUTE OF FUNDAMENTAL RESEARCH, SHIVAKOTE, HESARAGHATTA HOBLI, BENGALURU 560089

Speakers INFOSYS ICTS ALAN TURING LECTURES P. Ajith and The Alan Turing Lecture Series is a new initiative of ICTS. Loganayagam R, Aninda Sinha Toby Wiseman (SLAC, Stanford University) (Feynman Professor of Theoretical Physics at Caltech) ICTS - TIFR In this series, eminent Biologists, Computer Scientists, and Nima Arkani-Hamed Engineers are invited to deliver lectures on significant Consultation on National Education Policy IAS, Princeton developments in their areas. The first lecture in this series is aimed at a general scientific audience, while the remaining Sanjeev Arora two pedagogical lectures are aimed at specialists. Princeton ICTS at Ten Leon Balents Celebrating the Unity of Science KITP, Santa Barbara Manjul Bhargava Statistical Physics Methods in Kip Thorne won the 2017 Nobel Prize for Physics. Princeton Evolutionary William Bialek (NEP) 2017 Princeton MACHINE LEARNING Roger Blandford Stanford dynamics and Kavli Asian Winter School (KAWS) on Strings, Sourav Chatterjee The theme of this discussion meeting is the analysis of distributed/networked PARTICIPANTS Symmetry in Quantum Gravity algorithms in machine learning and theoretical computer science in the Stanford Varsha Banerjee, IIT Delhi "thermodynamic" limit of large number of variables. Methods from statistical physics Sakyajit Bhattacharya, Tata Consultancy Service, Kolkata Jennifer Chayes diversity in large (eg various mean– eld approaches) simplify the performance analysis of these Chiranjib Bhattacharyya, IISc Bangalore Microsoft Research algorithms in the limit of many variables. In particular, phase–transition like Arnab Bhattacharyya, IISc Bangalore Abhishek Dhar phenomena appear where the performance can undergo a discontinuous changes Vivek S. Borkar, IIT Bombay ✦ ICTS - TIFR as an underlying parameter is continuously varied. A provocative question to be Bikas K. Chakrabarti, Saha Institute of Nuclear Physics, Kolkata populations 2 December 2017 Organizers — Sutanu Chakrabarty, Manjul explored at the meeting is whether these methods can shed theoretical light into the IIT Madras Surya Ganguli workings of deep networks for machine learning. Sukhendu Das, IIT Madras Stanford Nivedita Deo, Delhi University Large populations, especially microbial, are continually evolving. ✦ Rama Govindarajan The discussion meeting will aim to facilitate interaction between theoretical Ambedkar Dukkipati, IISc Bangalore Particles and Cosmology 2018 Surya Ganguli, Stanford University 15 January 2018 Speaker — Understanding their evolutionary dynamics, the diversity it Hirosi Ooguri KAAPI WITH KURIOSITY ICTS - TIFR computer scientists, statistical physicists, machine learning researchers and Aditya Gopalan, IISc Bangalore mathematicians interested in these questions. Examples of speci c topics to be David Gross Manoj Gopalkrishnan, IIT Bombay generates, and how this can be sustained by ecological covered include (but are not limited to) problems such as phase transitions in KITP, Santa Barbara Suresh Govindarajan, IIT Madras interactions is a major challenge. These lectures will focus on key optimization and learning algorithms, matrix approximation, mixing in large Prateek Jain, Microsoft Research India, Bangalore Jonathon Howard networks, sub–linear time algorithms, learning theory and non convex optimization. Yoshiyuki Kabashima, Tokyo Institute of Technology questions, developing progress using ideas from statistical physics, Yale and The meeting will allow structured and unstructured interactions among the Mitesh Khapra, IIT Madras and interfacing with observations in the laboratory and nature Bhargava, Leena Chandran-Wadia Spenta R. The International Centre for Theoretical Sciences (ICTS-TIFR) began its journey on participants around the main theme. Bhumesh Kumar, IIT Bombay Shri Kulkarni nd 2 August, 2007 as a multi and interdisciplinary centre with programs, research and Caltech Anand Louis, IISc Bangalore that the enormous advances in DNA sequencing have enabled. outreach as its main goals. ICTS has now grown to have more than fifteen faculty in Rajsekar Manokaran, IIT Madras ✦ Joel Moore 8—18 January 2018 Organizers — Kaushik Mitra, IIT Madras Minxin Huang, diverse areas in the theoretical sciences. Over 150 programs and discussion meetings ORGANIZERS Lecture 1 | Monday, March 5, 4 pm to 5.30 pm (Fred Kavli Professor of Theoretical Physics and Endless Forms Most Beautiful UC Berkeley Shobhana Narasimhan, JNCASR, Bangalore have been held. The ICTS at Ten event is an opportunity to reflect on the journey thus Mikhail Belkin, Chandan Dasgupta, Partha Mitra, Rina Panigrahy Mahan Mj Hari Narayanan, TIFR Mumbai Statistical Dynamics of Complex Communities: from Random far, and to go ahead with renewed energy into our second decade, through a small Anshul Deep Singh Parmar, JNCASR, Bangalore TIFR, Mumbai DATE & TIME Matrices to Ecological Diversity celebratory scientific gathering. 26 December, 2017 to 30 December, 2017 Anand Raghunathan, Purdue University Ramesh Narayan Alpan Raval, LinkedIn Harvard VENUE Balaraman Ravindran, IIT Madras Ramanujan Lecture Hall, Srikanth Sastry, JNCASR, Bangalore Lecture 2 | Tuesday, March 6, 9.30 am to 11 am Wadia 4 - 6 January, 2018 Public Event Christos Papadimitriou ICTS, Bengaluru Kaushal Kumar Simmons, JNU New Delhi ICTS Campus, Columbia Sitabhra Sinha, The Institute of Mathematical Sciences, Chennai Processes and numbers: selection, mutation and drift On 7th January, 2018, there will be Suvrat Raju CONTACT US Aniruddha Sinha, Tata Consultancy Services, Kolkata ✦ Bengaluru [email protected] Ravi Sundaram, Northeastern University Sangmin Lee, Sungjay Lee, Loganayagam R, Suvrat Mathematics, Director of the Walter Burke Institute 25 March 2018 Speaker — a public event at Christ University. ICTS - TIFR Shannon Olsson Rajesh Sundaresan, IISc Bangalore Lecture 3 | Wednesday, March 7, 9.30 am to 11 am Robbert Dijkgraaf (IAS, Princeton) PROGRAM LINK Organisers Sriram Ramaswamy Manik Varma, Microsoft Research India, Bangalore will deliver a lecture on "The www.icts.res.in/discussion-meeting/SPMML2017 Adaptation of large asexual populations Rajesh Gopakumar IISc, Bengaluru Umesh Waghmare, JNCASR, Bangalore Usefulness of Useless Knowledge." Spenta R. Wadia David P Woodruff, IBM Research, CA DANIEL David Reitze Contact us The lecture will be followed by a Caltech Lecture 4 | Wednesday, March 7, 2 pm to 3.30 pm [email protected] panel discussion. The panellists are Sankar Das Sarma Statistics of asexual diversity and complexities of sexual Manjul Bhargava, Jennifer Chayes, University of Maryland Program Link Robbert Dijkgraaf, David Gross, dynamics www.icts.res.in/discussion Nathan Seiberg FISHER Narayana Murthy and and -meeting/icts-at-ten IAS, Princeton Raju, Tadashi Takayanagi, Masahito Yamazaki for Theoretical Physics, Caltech; Principal Investigator, (National Centre for Biological Sciences (NCBS), K. VijayRaghavan. Ashoke Sen Lecture 5 | Thursday, March 8, 9.30 am to 11 am The sessions will be streamed HRI, Allahabad Surface Group Representations and Geometric live – details will be updated This event is jointly hosted by Stanford University, USA Spatial dynamics and open questions on the program web page. ICTS-TIFR, IAS-Princeton, Infosys Madhu Sudan Science Foundation and Christ Harvard (deemed to be university) PARTICIPATION IN THE Mriganka Sur DANIEL FISHER is David Starr Jordan Professor SCIENTIFIC SESSIONS IS BY MIT INVITATION ONLY. of Science at Stanford University. Fisher 's 5-8 March 2018 Mukund Thattai research has spanned a spectrum of areas of Gang Yang ✦ Supported by Infosys Science Foundation and Simons Foundation NCBS - TIFR Ramanujan Lecture Hall, Kavli IPMU, The University of Tokyo and President, TIFR) Venue — J. N. Planetarium, Bangalore theoretical condensed matter physics including Nisheeth Vishnoi Structures EPFL, Lausanne superconductivity and earthquakes. Over the ICTS Bengaluru past fifteen years his interests have shifted to biology, including cellular biophysics, and his CONTACT US primary current focus – evolutionary and [email protected] ecological dynamics. Fisher has also been actively PROGRAM LINK involved in arms control and energy policy. 27—30 November 2017 ✦ Organizers — Siddhartha Aspen Center for Physics) www.icts.res.in/lectures/edlp2018 J—Holomorphic Curves and Gromov—Witten INFOSYS - ICTS Fascinating world of photons, superposition INFOSYS ICTS ALAN TURING LECTURES INFOSYS ICTS CHANDRASEKHAR The Alan Turing Lecture Series is a new initiative of ICTS. CHANDRASEKHAR LECTURE SERIES ICTS DISTINGUISHED LECTURE In this series, eminent Biologists, Computer Scientists, and LECTURE SERIES Engineers are invited to deliver lectures on significant Subrahmanyan Chandrasekhar Lecture Series are delivered developments in their areas. The first lecture in this series is by eminent physicists on important new developments in their Subrahmanyan Chandrasekhar Lecture Series are Gadgil, Krishnendu Gongopadhyay, Subhojoy aimed at a general scientific audience, while the remaining areas of speciality. The first lecture in any series is aimed at a delivered by eminent physicists on important new two pedagogical lectures are aimed at specialists. general scientific audience, while the remaining are targeted developments in their areas of speciality. The first lecture MYSTERIES OF at specialists. in any series is aimed at a general scientific audience, Invariants The SYK Model (Kavli Distinguished Lecture) and entanglement while the remaining are targeted at specialists. THE HIGGS The evolution of KATEPALLI SREENIVASAN NATHAN SEIBERG BOSON Gupta and Mahan Mj New York University individuality and why School of Natural Sciences, IAS, Princeton, NJ Katepalli Sreenivasan is Dean of the NYU Tandon School of Engineering and the Thirty-five years after it was postulated as a key component of the Seiberg received his Ph.D. in 1982 from the Weimann Institute ✦ Eugene Kleiner Professor for Innovation. At NYU he has the distinction of being a 16.00 − 17.30 theory of weak interactions, the Higgs boson was discovered at the ✦ ✦ University Professor, a title conferred upon scholars whose work is of Science, where he worked from 1985–91 as a Senior Scientist, 25 December 2017—4 January 2018 Organizers 8 January 2018 Speaker — (KITP — 25 February 2018 Speaker — life is hierarchically CERN Large Hadron Collider in 2012. Since that time, many decay David Gross Urbasi Sinha an Associate Professor and a Professor. During the years interdisciplinary and reflects exceptional breadth. He holds professorships in the modes of the Higgs boson have been observed, indicating couplings of Department of Physics and at the Courant Institute of Mathematical Sciences. 1989–97 he was a Professor at Rutgers University. After having 17 APRIL, 2018 the Higgs boson in good accord with the simplest theoretical structured visited the Institute for Advanced Study on several occasions as a Sreenivasan arrived at NYU after tenures at Yale, where he spent more than 20 expectations. The measurements suggest that the Higgs field has a Member and a Visitor from 1982–95, he joined the Faculty of the years and held multiple endowed professorships and chairmanships; the University nonzero amplitude everywhere in space. This field value, which gives of Maryland, where he led the Institute for Physical Science and Technology; and School of Natural Sciences in 1997. Since 1998 he has also been a Life is hierarchically structured, with replicating entities nested mass to all known elementary particles, was the result of a phase the International Centre for Theoretical Physics in Trieste, Italy, where he served as Visiting Lecturer with rank of Professor at Princeton University. transition in the early universe. However, we should not be complacent. within higher order self-replicating structures. Take, for example, director and held the Abdus Salam Professorship. He has also been a visiting RAMANUJAN HALL, multicellular life – the multicellular entity replicates, as do the cells professor at Caltech, Cambridge University, and the Institute for Advanced Study at Seiberg received many awards and honors including the John D. We do not know why this phase transition occurred. This is now a — Somnath Basu, Rukmini Dey and Ritwik University of California, Santa Barbara) (Quantum Information and Computing (QuIC) that comprise the organism. Inside cells are mitochondria that also Princeton, among other institutions. and Catherine T. MacArthur Foundation Fellowship, the Oskar central mystery of elementary particle physics, since explanations for have capacity for autonomous replication; the same is true of Klein Medal, the Dannie Heineman Prie for Mathematical ICTS, BENGALURU the Higgs field phase transition require new, hidden, particles and Sreenivasan’s research interests include fluid mechanics and turbulence, nonlinear chromosomes within the nucleus, and of genes that comprise Physics of the American Physical Society and the American Collective Dynamics of—, on— and around and nonequilibrium phenomena, and cryogenic helium. forces at distances smaller than those we have explored so far. In this chromosomes. Such hierarchical structure reflects a series of major Institute of Physics, the Fundamental Physics Prie, and the colloquium, I will describe what we know about the Higgs boson and evolutionary transitions in which lower order self-replicating entities He has been elected to the U.S. National Academy of Sciences, U.S. National Dirac Medal of the International Center for Theoretical Physics. [email protected] what we can learn about its mysteries from future, high-precision, have been subsumed within higher order structures. Typically this Academy of Engineering, American Academy of Arts and Sciences, Indian Academy Additionally, Seiberg is a member of both the American Academy measurements of the Higgs boson's interactions. involves the lower level entity “giving up its right to autonomous of Sciences, Indian National Science Academy, Indian National Academy of of Arts and Sciences and the National Academy of Sciences. Engineering, Academy of Sciences for the Developing World (TWAS), Accademia dei www.icts.res.in/lectures/higgs2018 replication” and with this “sacrifice” comes enslavement to the Lincei in Rome and African Academy of Sciences, among other such groups, and his Seiberg is a mathematical physicist, whose research has made “needs” of the higher order “corporate body”. Posed in these terms it many honors include the Guggenheim Fellowship, Otto Laporte Memorial Award and ✦ is difficult to see how evolutionary transitions unfold; how selection major contributions to understanding string theory, quantum Mukherjee Paul B Rainey Dwight Nicholson Medal of the American Physical Society, UNESCO Medal for laboratory at Raman Research Institute, Bangalore) field theory, and particle physics. His eact solutions of theories Department of Microbial Population Biology, Max Planck might shift levels and why life is hierarchically structured. Necessary Promoting International Scientific Cooperation and World Peace from the World have uncovered unepected insights, including the fundamental Institute for Evolutionary Biology, Plön, Germany for progress is clarity concerning what needs to be explained. Heritage Centre, and the Award for Scientific Cooperation of the American Filaments in Living Cells — Motors, MAPs, role of electric-magnetic duality in quantum field theories, and The speaker will argue that this is the evolution of Darwinian Association for the Advancement of Science. MICHAEL E. Laboratoire de Génétique de l’Evolution, Ecole they have led to many applications in physics and mathematics. Supérieure de Physique et de Chimie Industrielles de la Individuality — the evolution of properties of entities (variation, He has also clarified how supersymmetry can be dynamically Ville de Paris, Paris, France reproduction and heredity) that ensure participation in the process of DATES LECTURE 1 | 22 January 2018, 4 pm - 5.00 pm broken and tested, an effort now underway at the Large Hadron PUBLIC LECTURES evolution by natural selection. There has been a tendency to assume 22 - 24 January, 2018 The New Zealand Institute for Advanced Study, Massey Chandra's uid dynamics Collider. University, Auckland, New Zealand. these properties as pre-existing, but they are not – they are derived PESKIN and require evolutionary explanation. Pressing to the heart of the VENUE This talk will describe and assess S. Chandrasekhar's work in fluid dynamics from about Paul Rainey was born in New Zealand and problem, the challenge is to explain how Darwinian properties Ramanujan Lecture Hall, 1948 to 1960 and include remarks on his interactions during these years with leaders Venue — J. N. Planetarium, Bangalore LECTURE 1 (SLAC, Stanford University) completed his bachelors, masters and PhD at ICTS, Bangalore. in the field. A brief remark on Chandra's philosophy will follow. emerge from non-Darwinian entities by non-Darwinian means. This 8 January 2018 4 pm 5.30 pm the University of Canterbury. From 1989 until challenge permeates each evolutionary transition including the SYMMETRIES, TIPs and Tracks CONTACT US LECTURE 2 | 23 January 2018, 4 pm - 5.00 pm 2005 he was based in the UK where most of his emergence of life from non-life. The speaker will argue that solutions [email protected] LECTURE 2 Michael Peskin received his Ph.D. from Cornell University in 1978, time was as researcher and then professor at to this seemingly unsolvable problem arise once we consider ecology. From CMB to circulation – the search 9 January 2018 4 pm 5.30 pm DUALITY AND THE studying with Kenneth Wilson. After postdoctoral appointments at Winter School on Quantitative Systems the University of Oxford. He began He will also argue that the feedback between organismal PROGRAM LINK Harvard, CEN Saclay, and Cornell, he joined the staff of the SLAC Can Evolution be Understood Quantitatively? transitioning back to New Zealand in 2003, www.icts.res.in/lectures/cfd2018 for normal scaling characteristics and the amplifying effects of natural selection makes LECTURE 3 National Accelerator Laboratory at Stanford University, where he is firstly as Chair of Ecology and Evolution at the UNITY OF PHYSICS evolutionary transitions in individuality inevitable, and thus too, life’s After a brief introduction to the importance of scaling, normal and anomalous, we 11 January 2018 11 am 12.30 pm now a Professor of Particle Physics and Astrophysics. With Daniel University of Auckland, but then in 2007 hierarchical structure. discuss our search for normal scaling from cosmic microwave background radiation to Global symmetries and gauge symmetries have played a crucial Schroeder, Peskin is the author of "An Introduction to Quantum Field moved to the New Zealand Institute for circulation around closed contours. Circulation, in particular, has not received as much LECTURE 4 role in physics. The idea of duality demonstrates that gauge Theory", the most widely used graduate textbook on that subject. Advanced Study as one of its founding attention in turbulence as it deserves, though it plays an important role in fluid 12 January 2018 11 am 12.30 pm ✦ Lecture 1 symmetries can be emergent and might not be fundamental. 28 October—2 November 2017 Organizers — professors. Paul is currently Director of the dynamics. No special knowledge of the subject is expected. December 13, 2017, 4:00 pm – for general scientific audience. During the past decades, it became clear that the circle of ideas Department of Microbial Population Biology at VENUE about emergent gauge symmetries and duality is central in the Max Planck Institute for Evolutionary LECTURE 3 | 24 January 2018, 4 pm - 5.00 pm Ramanujan Lecture Hall, Lecture 2 different branches of physics including Condensed Matter Physics, ✦ Biology in Plön (Germany), Professor at ESPCI ICTS, Bangalore. Biology 6 March 2018 Speaker — (Stanford December 14, 2017, 4:00 pm. Turbulent mixing Quantum Field Theory, and Quantum Gravity. We will review Daniel Fisher Black Holes in Paris, and still spends some time at the these developments, which highlight the unity of physics. NZIAS, where he is a Distinguished Professor. A rich variety of features emerges when two substances mix with the aid of turbulence. CONTACT US He is a Fellow of the Royal Society of New Lecture 3 This talk is a summary of a few major themes on the topic, from the universal to the programicts.res.in December 15, 2017, 4:00 pm. Zealand and a Member of EMBO. anomalous. No special knowledge of the subject is expected. PROGRAM LINK Tanweer Hussain, Ambarish Kunwar and Prabal K www.icts.res.inlecturessdup2018 ✦ December 13 - 15, 2017  [email protected] 4—22 December 2017 Organizers — Sidhartha University) 21 January 2018 ✦ Speaker — Ramesh Narayan RAMANUJAN LECTURE HALL, www.icts.res.in/lectures/evolstruct17 ICTS BANGALORE ICTS at Ten Maiti Celebrating the unity of Science ICTS at Ten Goyal, Kavita Jain, Vijaykumar Krishnamurthy, Celebrating the unity of Science ICTS at Ten (Thomas Dudley Cabot Professor of the Natural ICTS PUBLIC LECTURE Celebrating the unity of Science    Public lecture and HIROSI OOGURI Can evolution            The Science of the Man from the 9 Dimensions   PUBLIC LECTURE & MOVIE SCREENING panel discussion   be understood and        Luca Peliti Mukund Thattai Sciences at Harvard University and Senior Astronomer  PUBLIC The science of  LECTURE      quantitatively? THE MAN FROM THE 9 DIMENSIONS ✦ Finishing his graduate study in 2 years, Ooguri became a tenured faculty member The basic laws of evolution have been known for more than a 14 January 2018 Speaker — Hirosi Ooguri at the University of Tokyo in 1986. He was a Postdoctoral Fellow at the Institute for "The Man from the 9 Dimensions" is a 3D dome theater movie on Superstring Theory, the leading Advanced Study and appointed an Assistant Professor at the University of Chicago century and there is overwhelming evidence for the facts of candidate for the unified theory of forces and matters including gravity. Professor Ooguri served before receiving his Ph.D. in 1989. He was an Associate Professor at Kyoto University as an advisor to the movie to ensure its scientific accuracy. The movie has received numerous In 2017, Princeton University evolution. Yet little is understood quantitatively about the prizes and honors including the 2016 Best Educational Production Award of the International and returned to the United States as the youngest Full Professor at UC Berkeley in Press published The Usefulness ✦ Planetarium Society and the 2017 Best Full Feature Film and Best 3D Show of the Immersive Film LECTURE SERIES of Useless Knowledge, in which at the Smithsonian Astrophysical Observatory) 1994. In 2000, he moved to Caltech, where he holds the Fred Kavli Chair. dynamical processes that drive evolution – by physicists' Festival in Portugal. Professor Ooguri will explain the science behind the movie, which will take Dijkgraaf and IAS founding standards the theory of evolution is far from fully-fledged. us from the microscopic world of elementary particles to the macroscopic world of the universe, At Caltech, Ooguri was the Deputy Chair of the Division of Physics, Mathematics, and to its beginning – the Big Bang. Director Abraham Flexner and Astronomy (equivalent of Vice Dean of Physical Sciences). He led the Huge advances in DNA sequencing technology and laboratory articulate how essential basic The trailer and other information on the movie can be found at research and original establishment of the Walter Burke Institute for Theoretical Physics, and he is its experiments have enabled direct observations of evolution in .com www.miraikan.jst.go.jp/sp/9dimensions/en/ thinking are to innovation Founding Director since 2014. Geometry, Groups and Dynamics (GGD) — 2017 and societal progress – a (Fred Kavli Professor of Theoretical Physics and action and together with theoretical developments, opened up THE LECTURE WILL BE FOLLWED BY SCREENING OF THE FILM, ‘THE MAN FROM THE 9 DIMENSIONS’ belief that has informed the In 2007, Ooguri helped establish the Kavli Institute for the Physics and Mathematics great opportunities for dramatically advancing our understanding. mission of the Institute for of the Universe in Japan, where he is a Founding Principal Investigator. He is also Robbert Dijkgraaf This talk will focus on framing questions and the challenges to be nearly ninety years. Venue — J. N. Planetarium, Bangalore the President of the Aspen Center for Physics in Colorado. iNSTITUTE FOR ADVANCED STUDY, pRINCETON, NJ faced, along with recent progress on addressing some of these. Ooguri is a Fellow of the American Academy of Arts and Sciences and an Investigator of the Simons Foundation. He has received the Eisenbud Prize from In his classic essay, The Usefulness of Useless Knowledge, Abraham Flexner, the Robbert Dijkgraaf, Director of the Institute for .renecampbellart.tumbl r       HIROSI OOGURI the American Mathematical Society, the Humboldt Research Award, and the founding director of the Institute for Advanced Study in Princeton and the Advanced Study and Leon Levy Professor since July        INFOSYS—ICTS TURING LECTURES man who helped bring Albert Einstein to the United States, describes a great 2012, is a mathematical physicist who has made ✦ Nishina Memorial Prize. His popular science books have sold over a quarter million Profile  6—24 November 2017 Organizers — paradox of scientific research. The search for answers to deep questions, significant contributions to string theory and the C. S. copies in Japan, and his science movie received the Best Educational Production Mathematics, Director of the Walter Burke Institute DANIEL FISHER is David Starr Jordan Professor of Science at  
  motivated solely by curiosity and without concern for applications, often leads advancement of science education. Award from the International Planetarium Society. Stanford University. Fisher 's research has spanned a spectrum      not only to the greatest scientific discoveries but also the most revolutionary His research focuses on the interface between     of areas of theoretical condensed matter physics including technological breakthroughs. In short, no quantum mechanics, no computer mathematics and particle physics. In addition to   chips. Robbert Dijkgraaf, the Institute’s current director, explains how finding surprising and deep connections between superconductivity and earthquakes. Over the past fifteen years 
    Flexner’s defense of the value of ‘the unobstructed pursuit of useless knowledge’ matrix models, topological string theory, and y Ren é Campbell | ww w

b may be even more relevant today than it was in the early twentieth century. supersymmetric quantum field theory, Dijkgraaf SYMMETRY IN his interests have shifted to biology, including cellular Dijkgraaf describes how basic research has led to major transformations in the has developed precise formulas for the counting biophysics, and his primary current focus – evolutionary and past century and explains why it is an essential precondition of innovation and of bound states that explain the entropy of certain Evolutionary Dynamics and Diversity in Large the first step in social and cultural change. black holes. For his contributions to science, ecological dynamics. Fisher has also been actively involved in QUANTUM GRAVITY abric of Life Aravinda, Shrikrishna Dani, Krishnendu for Theoretical Physics, Caltech; Principal Investigator, Dijkgraaf was awarded the Spinoza Prize, the Paleovirology — the modern legacy of ancient highest scientific award in the Netherlands, in arms control and energy policy. General relativity and quantum mechanics were crowning achievements of physics in The F 6.30 pm, 14.01.2018 2003. He was named a Knight of the Order of the the 20th century, and their unication has been le as our homework in the 21st Netherlands Lion in 2012 and is a member of the century. Superstring theory is our best candidate for the unication. Although J. N. PLANETARIUM, American Academy of Arts and Sciences and the PANELISTS American Philosophical Society. predictions of the theory are typically at extremely high energy and out of reach of BANGALORE current experiments and observations, several non–trivial constraints on its low Manjul Bhargava pRINCETON university energy eective theory have been found. Because of the unusual ultraviolet behavior Populations of gravitational theory, the standard argument for separation of scales may not work DANIEL FISHER Gongopadhyay and Athanase Papadopoulos for gravity, leading to robust low energy predictions of consistency requirements at Jennifer Chayes MICROSOFT RESEARCH, new england Kavli IPMU, The University of Tokyo and President, viruses Program Link high energy. In this talk, I will discuss why the unication of general relativity and David Starr Jordan Professor of Science, www.icts.res.in/lectures/uuk2018 quantum mechanics has been di€cult. Aer introducing the holographic principle as Dav i d Gross KITP, SANTA BARBARA our guide to the unication, I will turn our attention to its use to nd constraints on Stanford University. Register for the talk symmetry in a consistent quantum theory of gravity. I will also discuss the weak www.bit.ly/uuk2018 gravity conjecture, which gives a lower bound on Coulomb-type forces relative to the Narayana Murthy CO-FOUNDER, INFOSYS TECHNOLOGIES Contact us ✦ gravitational force, and consequences of the conjecture. 4 pm, 6 March 2018 [email protected] 8 March 2018 Speaker — Daniel S Fisher K. VijayRaghavan NCBS-TIFR & sECY, dbt, govt. of India ALL ARE WELCOME Aspen Center for Physics) 10 December 2017 ✦ Speaker — Chandrasekhar auditorium Harmit Malik 4 pm, 15.01.2018 ICTS Bangalore MAIN AUDITORIUM RAMANUJAN LECTURE ALL ARE WELCOME   [email protected]   www.icts.res.in/lectures/evquant2018 ANUARY 1 4PM CHRIST UNIVERSITY (Stanford University, USA) HALL, ICTS. (Fred Hutchinson Cancer Research Center, Seattle,   
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­ €‚ƒ„ ICTS at Ten DISCUSSION Celebrating the unity of Science The Usefulness of Useless Knowledge Image – Orthographic projection of enneract making the petrie polygon | CC–BY–3.0 Claudio Rocchini ✦ IN AS SOC I A TION WI T H USA) Venue — J. N.Planetarium, Bangalore In NovemberESTD. 1946 1915, Albert Einstein proposed the General Theory of Relativity, which revolutionized our understanding of gravity and became one of the pillars of modern physics. ICTS plans to organize a public The evolution of individuality and why life is ICTS PUBLIC LECTURE lecture series, called “Einstein Lectures,” ✦ celebrating the centenary year of General 7 January 2018 Speaker — Robbert Dijkgraaf Relativity. Educational institutions and other public organizations from all over India are invited to partner with ICTS in organizing public lectures at various venues MEETINGS in India. ICTS is in the process of assembling Deciphering the workings Einstein a vibrant pool of Einstein speakers KAAPI WITH KURIOSITY N N A The program aims to bring together theorists spanning a wide spectrum, ranging from working in the areas of lattice field theory, string early-career scientists to international theory, and quantum gravity to discuss the state of molecules, building luminaries. Einstein lectures will carry the message of Einstein’s triumphant theory of the art nonperturbative methods and numerical hierarchically structured lectures and its impact on modern physics and Q G approaches to tackle current and relevant blocks of life, with the astronomy, and the spirit of discovery and (IAS, Princeton) Einstein Shannon Olsson problems in string theory and holography. Shapes and geometry of surfaces PUB LIC LEC T URE SERIES CELEBR A TING T HE CE NTE NARY OF scientific temper. heads the Naturalist-Inspired Chemical Ecology (NICE) group at the electron microscope. ALBER T EIN S T E IN’S GENER A L THE O R Y OF REL A TIVIT Y National Centre for Biological Sciences (NCBS-TIFR) in Bangalore. The NICE The open call for partner organizations, S T PEDAGOGICAL LECTURES along with a list of Einstein lecturers and is particularly interested in how animals, and especially insects, identify topics will be published on the ICTS web site We will have a series of pedagogical lectures on each of objects across different environments. Dr. Olsson completed her Ph.D. at in August. Selected partner organizations the following topics – Public lecture by will work with ICTS in selecting an Cornell University in Neurobiology and Behavior and Chemical Ecology. She H lecturesappropriate speaker depending on the date Kaapi with Kuriosity is a monthly Lattice Supersymmetric Field Theories ✦ and venue of the lecture, and the nature of public lecture series organised then worked at the Ma Planck Institute for Chemical Ecology in Jena, Simon Catterall (Syracuse Univ.) Pressing for Progress — A Discussion Meeting the audience. ICTS will provide the necessary 13, 14, 15 December 2017 Speaker — Germany, as a Project Leader where she collaborated with engineers to Paul B by the International Centre for &de- support to organize the event, and the t_width); Matrix Models, Quantum Black Holes and Gravity ✦ partner organizations are expected to take Theoretical Sciences (ICTS–TIFR), develop an artificial chemical communication system based on insect node0_printf("FLINK"); Rana Adhikari Masanori Hanada (Kyoto Univ.) 26 November 2017 Speaker — (TIFR, FORALLDIR(dir) Mahan Mj care of the local organization. node0_printf(" %.6g", linktr[dir]); in collaboration with the chemical communication. A Fulbright Scholar and Ramanujan Fellow, Dr. node0_printf(" %.6g %.6g\n", linktr_ave, linktr_width); Conformal Bootstrap Jawaharlal Nehru Planetarium node0_printf("FLINK_DET"); California Institute of Technology, USA Olssons favourite thing about being a scientist is the privilege to observe FORALLDIR(dir) Madalena Lemos and Pedro Liendo (DESY) http://www.icts.res.in/lecture/einstein and other educational node0_printf(" %.6g", link_det[dir]); and learn, every day, something completely new, and the possibility that the node0_printf(" %.6g %.6g\n", det_ave, det_width); Resurgence and Trans-series in Quantum Field Theories institutions in Bengaluru. something new could make a positive difference in this world. // Polyakov loop and plaquette measurements Gerald V. Dunne (Univ. of Connecticut) Photograph − // Format: GMES Re(Polyakov) Im(Poyakov) cg_iters ss_plaq // st_plaq Brian Winkowski, plp = ploop(TUP, NODET, &plpMod); Deciphering the Workings of Molecules, © Columbia University Medical Center. In Brightest Day plaquette(&ss_plaq, &st_plaq); node0_printf("GMES %.8g %.8g 0 %.8g %.8g ", SPEAKERS on the Gender Gap in Physics (Department of Microbial Population Biology, ictstifr plp.real, plp.imag, ss_plaq, st_plaq); Rainey Andrei Alexandru (The George Washington Univ.) // Bosonic action (printed twice by request) and Blackest Night // Might as well spit out volume average of ✦ // Polyakov loop modulus Adi Armoni (Swansea Univ.) Joachim Frank is a Professor in the Department ictstifr Mumbai) Venue — J. N. Planetarium, Bangalore e ss_plaq = gauge_action(NO- b (Dublin Institute for Advanced Studies) a Yuhma Asano of Biochemistry and Molecular Biophysics, and in ost uti DET) / (double)vol- m fu ume; Connor Behan (Stony Brook) the Department of Biological Sciences of “ ms l” // ICTStalks E r Columbia University, New York, USA. Nearly 100 years a er being predicted by Albert Einstein, the nd s fo Georg Bergner (Univ. of Jena)

yashida les Evan Berkowitz (Julich Research Centre) Resolution before 2013 Present Resolution LIGO project has detected gravitational radiation from outer Prof. Frank has been honored with numerous Richard Brower (Boston Univ.) Hashem et al., Nature 2013 Liu et al., PNAS 2016 space. The orbits and collisions of black holes from billions of icts.res.in/outreach prizes, the latest being the Nobel Prize for One of the most fundamental questions in our pursuit to Simon Catterall (Syracuse Univ.)

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✦ years ago produce massive distortions in the spacetime C r Chemistry in 2017 "for developing http://www.icts.res.in/lecture/einstein Shailesh Chandrasekharan (Duke Univ.) 22 March 2018 Organizer — Prajval Shastri [email protected] understand our living world is how new species come to be, Max Planck Institute for Evolutionary Biology, Plön, We stand at the culmination of a technological development cryo-electron microscopy for the continuum. These waves can now be detected on the earth creating the vast biodiversity that eists on our planet. Here, I will Alessandro D’Adda (INFN, Turin) that lasted for decades, and went largely unnoticed until high-resolution structure determination of Soumen Datta (TIFR) using ultra-sensitive, kilometer scale, laser interferometers. A tell the story of how scientists across continents and disciplines recently. It involved many innovations of instrumentation, biomolecules in solution". Rana Adhikari is Professor of Physics at 080 6730 6000 Gerald V. Dunne (Univ. of Connecticut) of sample preparation, and computer processing methods worldwide network of these machines is now opening up the the California Institute of Technology, have tracked this question over 150 years for a most humble Antonio Gonzalez-Arroyo (UAM, Madrid) Some of the other prestigious awards include for which this year’s Nobel Price in Chemistry has been field of gravitational wave astronomy. In order to study the creature – a fly. Starting under an apple tree with one of Darwins Sourendu Gupta (TIFR) Wiley Prize of Life Science, Franklin Institute USA. He is one of the world-leading awarded. As a result, molecules which form the basis of life classmates, to a virtual realty arena in Bangalore, we will discuss Masanori Hanada (Kyoto Univ.) Medal for Life Science, Scientific Merit Award for geometry of the universe and detailed nature of black holes, experts on the experimental physics of REGISTER ONLINE functions in the cell can now be imaged with unprecedented Goro Ishiki (Univ. of Tsukuba) the 4th Quarter Century with the NYS Department these interferometers have to be able to measure motions how tiny changes in the brain of an insect can lead to changes in clarity, even at near – atomic resolution. Their actions as gravitational-wave detection and is one of Raghav Govind Jha (Syracuse University) Microscope behavior, and ultimately, the beginning of a new species. molecular machines can even be analyzed and captured in of Health, Wadsworth Distinguished Scientist in thousands of times smaller than a proton. I will describe what the key contributors responsible for the Dates Daisuke Kadoh (Keio Univ.) Germany; Laboratoire de Génétique de l’Evolution, movies. In this lecture the challenges and milestones Structural Biology, Howard Hughes Medical has been done to get to this level of sensitivity and what the David B. Kaplan (Univ. of Washington) Institute Investigator Award, George E. Palade success of LIGO’s experimental physics 27 January to 3 February, 2018 leading to a new era in Structural Biology and, ultimately, Noboru Kawamoto (Hokkaido Univ.) Distinguished Lecture and Gold Medal. next advances in materials science and metrology may yield in program, which led to the recent Molecular Medicine will be illustrated. Madalena Lemos (DESY) terms of fundamental physics and cosmology. detection of gravitational waves. His Venue Prof. Frank is an Elected Fellow of the Biophysical ICTS Bangalore Pedro Liendo (DESY) research interests are related to Society, the American Academy of Microbiology, www.bit.ly/efmb_olsson Biagio Lucini (Swansea Univ.) Analytic and Algebraic Geometry gravitational-wave astronomy, tests of Dalimil Mazac (Perimeter Institute) the American Association for the Advancement of 20 Feb 2018 (Tuesday) at 2 pm Registration deadline ✦ Date and Time Science, American Academy of Arts and Sciences, fundamental physics using tabletop 20 October, 2017 Denjoe O'Connor (Dublin Institute for Advanced Studies) 1 November 2017 Speaker — st David Schaich (Univ. of Bern) Joachim Frank 1 November 2017, 4.00 pm to 5.30 pm National Academy of Sciences USA. BMS Auditorium, Library building, experiments, and studies of space Contact us Ricardo Schiappa (Univ. of Lisbon) ESPCI Paris, France & The New Zealand Institute for Prof. Frank is currently visiting ICTS as “Simons missions for gravitational-wave detection. When & where Venue Fumihiko Sugino (Institute for Basic Science) BMS College of Engineering, 4 pm, Sunday, [email protected] Chandrasekhar Auditorium, Visiting Professor” Urs Wenger (Univ. of Bern) 25th March, 2018 ICTS, Bangalore Bull Temple Road, Bangalore - 560019 Website Andreas Wipf (Univ. of Jena) Badis Ydri (Badji Mokhtar-Annaba Univ.) ✦ J. N.Planetarium, www.icts.res.in/program/NUMSTRINGS2018 19—24 March 2018 Organizers — Indranil Biswas Program page jOACHIM fRANK Sri T. Chowdaiah Road, www.icts.res.in/lectures/dwm17 International Centre for Theoretical Sciences Organisers During the program, Prof. David B. Kaplan (Univ. of (Columbia University, New York) cOLUMBIA uNIVERSITY Tata Institute of Fundamental Research High Grounds, Poul H. Damgaard, Masanori Hanada, Anosh Joseph, Washington, Seattle) will deliver the distinguished Reach us at Shivakote, Hesaraghatta Hobli, Bangalore 560089 Bangalore – 560 001 Loganayagam R, Aninda Sinha and Toby Wiseman Infosys – ICTS Chandrasekhar Lecture. Advanced Study, Massey University, Auckland, New [email protected] nEW YORK Tel 080 4653 6051 E-mail [email protected] https://icts.res.in/lectures/einstein All are welcome. All are welcome. 2017 Nobel prize in Chemistry ADMISSION FREE. REGIS TER ONLINE AT - www.bit.ly/EL_20Feb2018_RA Si and Parijat Sukanya Olkar, Yadav, Image - Deepak Kakara, Dinesh and A. J. Parameswaran INTERNATIONAL CENTRE FOR THEORETICAL SCIENCES,TATA INSTITUTE OF FUNDAMENTAL RESEARCH, SHIVAKOTE, HESARAGHATTA HOBLI, BENGALURU 560089 Zealand) Joachim Frank won the 2017 Nobel Prize for

Chemistry. This was his first public lecture since JAWAHARLAL NEHRU PLANETARIUM Indian Statistical Physics Community Meeting KAAPI WITH KURIOSITY KAAPI WITH KURIOSITY

INFOSYS—ICTS CHANDRASEKHAR PALEOVIROLOGY: winning the Prize. MAHAN MJ THE MODERN LEGACY OF Prof. Mahan Mj was born Mahan Mitra 2018 ? in 1968 and went to St. Xavier’s ANCIENT VIRUSES Collegiate School in Kolkata. He went Kaapi with Kuriosity is a monthly Kaapi with Kuriosity is a monthly to IIT-Kanpur, initially to major in public lecture series organised "Paleovirology” is the study of public lecture series organised by the International Centre for ancient extinct viruses (called Electrical Engineering, but switched by the International Centre for LECTURES Theoretical Sciences (ICTS–TIFR), “paleoviruses”) and the effects that later to mathematics and graduated Theoretical Sciences (ICTS- in collaboration with the these agents have had on the with a Masters degree in 1992. TIFR), in collaboration with the Jawaharlal Nehru Planetarium evolution of their hosts. I will focus Jawaharlal Nehru Planetarium He received his Ph.D. from the and other educational on studies that have employed and other educational University of California, Berkeley in ✦ institutions in Bengaluru. 16—18 February 2018 Organizers — computational and genetic Ranjini institutions in Bengaluru. 1997. His thesis was called Maps on techniques to identify such ancient Boundaries of Hyperbolic Metric viruses, or their evolutionary EINSTEIN LECTURES ictstifr Spaces. He received the Shanti imprints, in our genomes. I will also ictstifr Swarup Bhatnagar award in 2011. Computing Reality discuss how such studies reveal an ictstifr Prof. Mahan has made a substantial undescribed landscape of ancient ictstifr viral infections, and novel insights impact in the fields of geometric ICTStalks The mummi ed head of Ramses V of Egypt (died 1157 BC) into how to combat pathogenic group theory, low-dimensional showing the pustular eruption that may have been due to ICTStalks viruses today. topology and complex geometry. Bandyopadhyay, Abhishek Dhar, Kavita Jain, smallpox (From Smith, 1917) icts.res.in/outreach His work in these fields is characterised icts.res.in/outreach In Brightest Day and Blackest Night by its creativity and clever use of [email protected] 31 January 2018 ✦ Speaker — David B. Kaplan [email protected] delicate geometric arguments. 080 6730 6000 HARMIT MALIK Harmit Malik got his B. Tech (Chemical Engineering) 080 6730 6000 from IIT Bombay, where he became interested in molecular biology due to Prof. K.K. Rao and in evolution REGISTER ONLINE Rahul Pandit, Sanjib Sabhapandit, Samriddhi by reading Richard Dawkins’ “The Selfish Gene”. He REGISTER ONLINE 20 February 2018 ✦ Speaker — pursued PhD in Biology, at the University of Rochester, Rana Adhikari NY, under the mentorship of Prof. Thomas Eickbush. In (University of Washington, USA) 1999, he moved to Seattle to the Fred Hutchinson Cancer Research Center (the “Hutch"), to do his postdoc SHAPES AND with Dr. Steve Henikoff. In 2003, he started his own lab GEOMETRY at the Hutch. In 2009, he was awarded an Early Career www.icts.res.in/outreach/register Scientist of the Howard Hughes Medical Institute and a OF SURFACES Sankar Ray and Prerna Sharma Full Investigator in 2013. ✦ Almost all shapes that we see around (Professor of Physics, Caltech) Venue — Library Harmit Malik studies the causes and consequences of When & where in space are examples of surfaces. When & where genetic conflicts that take place between different We shall describe a method dating 4 pm, Sunday, genomes (e.g., host-virus interactions, mitochondrial 4 pm, Sunday, 10th December, 2017 conflicts with nuclear genomes) or between components of the same genome (e.g., 26th November, 2017 back to the 19th century of chromosomal competition at centromeric regions). He is interested in understanding understanding these. J. N.Planetarium, these "molecular arms races" and how they drive recurrent genetic innovation, from the J. N.Planetarium, Time-permitting, we shall describe Sri T. Chowdaiah Road, perspective of both evolutionary biology and human disease. Malik and his colleagues Sri T. Chowdaiah Road, more sophisticated geometric High Grounds, have used an evolutionary lens to dissect and discover both primate antiviral as well as High Grounds, structures on surfaces. Auditorium, BMS College of Engineering, Bangalore Bangalore - 560 001 viral adaptation strategies. By taking advantage of viral ‘fossils’ in animal genomes and Bangalore - 560 001 intense episodes of ancient host gene adaptation, his work has helped found the field of Image - H. Zell | Wikimedia Commons All are welcome. Paleovirology. His lab has been able to describe functional outcomes of ancient host-virus arms races by resurrecting both host and viral proteins from the evolutionary record. All are welcome

INTERNATIONAL CENTRE FOR THEORETICAL SCIENCES,TATA INSTITUTE OF FUNDAMENTAL RESEARCH, SHIVAKOTE, HESARAGHATTA HOBLI, BENGALURU 560089 INTERNATIONAL CENTRE FOR THEORETICAL SCIENCES, TATA INSTITUTE OF FUNDAMENTAL RESEARCH, SHIVAKOTE, HESARAGHATTA HOBLI, BENGALURU 560089 www.icts.res.in www.icts.res.in VOLUME IV ISSUE 1 NEWS 2018

TATA INSTITUTE OF FUNDAMENTAL RESEARCH

PAGE 1 ICTS TURNS 10

PAGE 4 QUANTUM ENTANGLEMENT AND THE GEOMETRY OF SPACETIME

With hindsight, it might appear PAGE 6 that there had been a grand and GRAVITY'S FATAL ATTRACTION premeditated design to address the outstanding problems “ PAGE 11 concerning the origin and evolution of the universe. THE SCIENTIFIC LEGACY OF But it was not really like that. STEPHEN HAWKING (1942 — 2018) I did not have a master plan; rather I followed my nose and did whatever looked interesting and possible at the time. Stephen Hawking ”

Editor - Ananya Dasgupta Design - ICTS Permanent Address Juny K. Wilfred Survey No. 151, Shivakote village, Hesaraghatta Hobli, North Bengaluru, India 560089 Website www.icts.res.in