DOCSLIB.ORG

Del Big Bang Al Futur De L'univers

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Del Big Bang Al Futur De L'univers Institute of Space Sciences Cosmology and Zeta Functions: XXV years Trento-Barcelona colab* Emilio Elizalde Trento, June 2017 *To Sergio Zerbini, a wonderful physicist and a generous friend Name or Title or Xtra Institute of Space Sciences Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences MY FIRST TIME IN TRENTO Jacob Bekenstein: All black holes have a finite, non-zero entropy and temperature Stephen Hawking: All Schwarzschild black holes of mass M emit electro- magnetic radiation like a black body with a temperature Hawking's result improved and dramatically extended the conjecture and BH entropy formula by Jacob Bekenstein. It was a bombshell: How on Earth could a BH radiate ??? SW Hawking, Particle creation by black holes, Comm. Math. Phys. 43, 199 (1975); Black hole explosions? Nature 248, 30 (1974) JD Bekenstein, Black holes and entropy, Phys. Rev. D7, 2333 (1973) Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences Some scholars tried very hard to disprove his marvelous universal expression “I distinctly remember that year, 1975, attending as a graduate student my first international school at Schladming (Austria); after a wonderful trip by car, with a couple of colleagues from Barcelona, through the spectacular North-Italian lakes and the Brenner pass in the Alps. What a magnificent meeting was this!” Julian Schwinger lectured as the star there, but the excitement about Hawking's result kept growing every day during the sessions. No wonder that Hawking's article has got a record number of over 9,000 cits Participants in the Schladming school all worked with a preprint version of Hawking's paper E Elizalde, “On how the Cyberspace arose to fulfill theoretical physicists' needs and eventually changed the World”, in Cyberspace, Springer Verlag (2017) to appear; arXiv:1701.04765 Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences LAST MINUTE ADD 1: EMOOCs Conference 2017 FIFTH EUROPEAN MOOCS STAKEHOLDERS SUMMIT Digital Education: Out to the world and back to the campus http://emoocs.eu/ Massive Open Online Courses (MOOCs) have marked a milestone in the use of technology for education MOOCs are free courses However, if you want a certificate you must negotiate with the implicated Universities or Centers that extend them Harvard Online Learning CaltechX Free online courses from Caltech Oxford University Online and distance courses online learning The Open University Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences LAST MINUTE ADD 2: IMU Newsletter, May 31, 2017 EDITORIAL: GRAID: A NEW IMU PROGRAM FOR GRADUATE ASSISTANTSHIPS IN DEVELOPING COUNTRIES Mathematicians from developing countries who chose to return to their home country after obtaining a promising Ph.D. degree at a high quality research institution, used to find that it was virtually impossible to keep up with their field - their isolation from new directions, the lack of libraries, the high cost of travel to conferences or possible collaborators … Internet and its embrace by researchers have changed all that … … findings online, before they are published, to share with the whole research community In short, it is now possible for cohorts of graduate students in developing countries to reach mathematical levels achieved only rarely outside major research centers This has potentially far-reaching consequences: as shown at the MENAO symposium: http://www.mathunion.org/cdc/menao/ Opportunity recognized by several organizations, which have responded with initiatives that make graduate studies and research possible for talented students in many parts of the world Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences ON OUR COLLABORATION OF XXV YEARS Started in 1992, “go betweens” Andrei Bytsenko and Sergei Odintsov Later, Klaus Kirsten Our works are pioneering and have got international recognition in some domains of fundamental physics, cosmology and mathematical physics top international level One fundamental achievement concerns the development and uses in Physics of the Zeta Function Regularization procedure Other key achievements have to do with modified gravity theories, in particular f(R) models and variations of them (GB, torsion, etc.) Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences Zeta-function regularization, the multiplicative anomaly and the Wodzicki residue, E Elizalde, L Vanzo, S Zerbini Dark energy in modified Gauss-Bonnet gravity: Late-time acceleration and the hierarchy problem, G Cognola, E Elizalde, S Nojiri, SD Odintsov, S Zerbini Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences SOME SEMINAL BOOKS & PAPERS E . Elizalde, S.D. Odintsov, A. Romeo, A.A. Bytsenko and S.Zerbini, Zeta regularization techniques with Applications (World Sci., Singapore, 1994). ISBN 9810214413. - Cit 860 G Cognola, E Elizalde, S Nojiri, SD Odintsov, S Zerbini, Dark energy in modified Gauss- Bonnet gravity: Late-time acceleration and the hierarchy problem, Phys Rev D73, 084007 (2006) - Cit 402 G Cognola, E Elizalde, S Nojiri, SD Odintsov, L Sebastiani, S Zerbini, Class of viable modified f (R) gravities describing inflation and the onset of accelerated expansion, Phys Rev D77, 046009 (2008) - Cit 389 G Cognola, E Elizalde, S Nojiri, SD Odintsov, S Zerbini, One-loop f (R) gravity in de Sitter universe, J Cosmol Astrop Phys 2005, 010 (2005) - Cit 311 G Cognola, E Elizalde, S Nojiri, SD Odintsov, S Zerbini, String-inspired Gauss-Bonnet gravity reconstructed from the universe expansion history and yielding the transition from matter dominance to dark energy, Phys Rev D75, 086002 (2007) - Cit 147 E Elizalde, L Vanzo, S Zerbini, Zeta-function regularization, the multiplicative anomaly and the Wodzicki residue, Commun Math Phys 194, 613-630 (1998) - Cit 125 Name or Title or Xtra EE, Sergio Zerbini’s Fest Institute of Space Sciences Sergio, ti auguro una vita lunga e felice in seguito, con Lucia, e Livio, e Giulia, e … Name or Title or Xtra EE, Sergio Zerbini’s Fest.
Load more

Recommended publications
  • Mar Bastero Gil Initial Conditions for Inflation: the Role of Fluctuation-Dissipation Dynamics. Francisco Torrentí Higgs-Curvat
    MONDAY, APRIL 10th 09:20-10:20 Iván Agulló Loop Quantum Cosmology and the Cosmic Microwave BacKground. 10:20-10:40 João Morais PrE-inflationary imprints in thE CMB: thE casE for smooth transitions. 10:40-11:00 Mar Bastero Gil Initial conditions for inflation: the role of fluctuation-dissipation dynamics. 11:00-11:20 Grigorios Panotopoulos Natural Inflation on thE branE with a TEV-scale gravity: Parameter constraints after Planck 2015. 11:20-12:00 CoffEE BrEaK 12:00-12:20 Francisco Torrentí Higgs-curvature coupling and post-inflationary vacuum instability. 12:20-12:40 Carlos Tamarit Unifying inflation with the axion, dark matter, baryogenesis and the seesaw mechanism. 12:40-13:00 Sulona Kandhai Investigating 4th order gravity: SNIa constraints on a viable model for f(R) gravity 13:00-13:20 Miguel Méndez Isla An analysis of results in indirect searches of Dark Matter 13:20-15:00 Lunch 15:00-15:20 Sergio Pastor The effective number of neutrinos: standard and non-standard calculations. 15:20-15:40 Pablo Fernández de Salas Local density of relic neutrinos with minimal mass. 15:40-16:00 A. Delhom Observable traces of non-metricity: accelerator constraints on metric-affine gravity. 16:00-16:20 Clara Álvarez Luna Dark photon searches with atomic transitions. CoffEE BrEaK 16:40-17:00 Iker Leanizbarrutia Analysing a forecast cosmological redshift drift. 17:00-17:20 Andras Kovacs The ISW imprint of Supervoids: from simulations to DES, BOSS and Euclid data. 17:20-17:40 Ana Alonso-Serrano Entropy budget in black hole evaporation.
    [Show full text]
  • Abstract Book
    1st International Conference on Symmetry Parc Científic de Barcelona Barcelona, Spain 16 - 18 October 2017 Conference Chair Sergei D. Odintsov Conference Co-Chairs Cino Pertoldi Kimball A. Milton Maurizio Benaglia Organised by Conference Secretariat Antonio Peteira Nikoleta Kiapidou Demi Liu Pablo Velázquez Kristjana Xhuxhi Sara Martínez Lucia Russo Sarai Rodríguez 1st International Conference on Symmetry 1 CONTENTS Abridged Programme 5 Symposium Programme 6 Welcome 15 General Information 17 Abstracts – Session 1 25 Biology and Symmetry Abstracts – Session 2 55 Physics and Symmetry Abstracts – Session 3 113 Chemistry and Symmetry Abstracts – Session 4 137 Mathematics, Computer Science and Symmetry Abstracts – Poster Exhibition 171 List of Participants 193 1st International Conference on Symmetry 3 1st International Conference on Symmetry 16-18 October 2017, Barcelona Monday Tuesday Wednesday 16 October 2017 17 October 2017 18 October 2017 S2. Physics and S3. Chemistry and Symmetry Symmetry Session Chairs Session Chair Kimball A. Milton Maurizio Benaglia Iver Brevik Check-in Coffee Break & Poster Session Morning S2. Physics and S3. Chemistry and Symmetry Symmetry Session Chairs Session Chair Kimball A. Milton Maurizio Benaglia Emilio Elizalde Lunch Opening Ceremony S2. Physics and S4. Mathematics, Symmetry Computer Science Conference Chair and Symmetry Sergei D. Odintsov Session Chairs Kimball A. Milton Session Chair S1. Biology and Carl Bender Sergei D. Odintsov Symmetry Session Chair Cino Pertoldi Coffee Break & Poster Session Afternoon
    [Show full text]
  • Arxiv:1912.05202V2 [Gr-Qc]
    Stellar structure models in modified theories of gravity: lessons and challenges Gonzalo J. Olmo Depto. de F´ısica Te´orica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Burjassot-46100, Valencia, Spain. Departamento de F´ısica, Universidade Federal da Para´ıba, 58051-900 Jo˜ao Pessoa, Para´ıba, Brazil. Diego Rubiera-Garcia Departamento de F´ısica Te´orica and IPARCOS, Universidad Complutense de Madrid, E-28040 Madrid, Spain Aneta Wojnar N´ucleo Cosmo-ufes & PPGCosmo, Universidade Federal do Esp´ırito Santo, 29075-910, Vit´oria, ES, Brasil Laboratory of Theoretical Physics, Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411 Tartu, Estonia Abstract The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravita- tional interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong field regime of General Relativity, and opens fruitful avenues for the exploration of new gravitational physics. The latter can be captured via modified theories of gravity, which modify the Einstein-Hilbert action of General Relativity and/or some of its principles. These theories typically change the Tolman-Oppenheimer-Volkoff equations of stellar’s hydrostatic equilibrium, thus having a large impact on the astrophysical properties of the corresponding stars and opening a new window to constrain these theories with present and future observations of different types of stars. For relativistic stars, such as neutron stars, the uncertainty on the equation of state of matter at supranuclear densities intertwines with the new parameters coming from the modified gravity side, providing a whole new phenomenology for the typical predictions of stellar structure models, such as mass-radius relations, maximum masses, or moment of inertia.
    [Show full text]
  • Arxiv:1902.08020V3 [Gr-Qc]
    Charged spherically symmetric Taub-NUT black hole solutions in f (R) gravity 1,2 3 G.G.L. Nashed ∗ and Kazuharu Bamba † 1Centre for Theoretical Physics, The British University in Egypt, P.O. Box 43, El Sherouk City, Cairo 11837, Egypt 2Egyptian Relativity Group (ERG), Cairo University, Giza 12613, Egypt and 3Division of Human Support System, Faculty of Symbiotic Systems Science, Fukushima University, Fukushima 960-1296, Japan f (R) theory is a modification of Einstein general relativity which has many interesting results in cosmology and astrophysics. To derive black hole solution in this theory is difficult due to the fact that it is fourth order differential equations. In this study, we use the first reliable deviation from general relativity which is given by the quadratic form of f (R) = R + βR2, where β is a dimensional parameter. We calculate the energy conditions of the charged black holes and show that all of them are satisfied for the Taub-NUT spacetime. Finally, we study some thermodynamic quantities such as entropy, temperature, specific heat and Gibbs free energy. The calculations of heat capacity and free energy show that the charged Taub-NUT black hole have positive values which means that it has thermal stability. PACS numbers: 04.50.Kd, 04.80.Cc, 95.10.Ce, 96.30.-t, 98.80.-k Keywords: f (R) gravitational theory; black holes; singularities; thermodynamic quantities arXiv:1902.08020v3 [gr-qc] 17 Feb 2020 ∗ [email protected] † [email protected] 2 I. INTRODUCTION The Hilbert-Einstein Lagrangian which involves higher order corrections of Ricci scalar has been used a long time ago as a result of the quantum correction to the gravitational field of the matter source [1].
    [Show full text]
  • Precision Predictions of Primordial Power Spectra
    PRECISION PREDICTIONS OF PRIMORDIAL POWER SPECTRA By DANIEL BROOKER A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2018 © 2018 Daniel Brooker I dedicate this to my beautiful wife Elizabeth without whom I would be hopelessly lost. ACKNOWLEDGMENTS This work would not have been possible without my wonderful advisor Richard Woodard as well as our incredible collaborators Nick Tsamis and Sergei Odintsov. In the long course of research that went into this thesis and the works which comprise it we profited at various times from conversations with: P. K. S. Dunsby, L. Patino, M. Romania, S. Shandera, M. Sloth, J. Garcia-Bellido, and M. Sasaki. This work was supported by NSF grant PHY1506513, by a travel grant from the UF International Center, by the UF’s McLaughlin fellowship, and by the UF’s Institute for Fundamental Theory. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................... 4 LIST OF TABLES ...................................... 7 LIST OF FIGURES ..................................... 8 ABSTRACT ......................................... 10 CHAPTER 1 INTRODUCTION, MOTIVATION, AND BACKGROUND .............. 11 1.1 Introduction ................................... 11 1.2 Cosmic Preliminaries ............................... 11 1.2.1 Basic Facts and Definitions ....................... 11 1.2.2 The Need for Inflation .......................... 13 1.2.2.1 The horizon problem ..................... 13 1.2.2.2 The flatness and monopole problems ............. 13 1.3 An Easy Way To Produce Inflation ....................... 14 1.4 Generic Predictions Of Inflation ......................... 17 1.4.1 Spontaneous Particle Production During Inflation ............ 17 1.4.2 Quantum Fields and Mode Equations .................. 18 1.4.3 The Constant Epsilon Solution ....................
    [Show full text]
  • Collapse of a Relativistic Self-Gravitating Star with Radial Heat Flux: Impact of Anisotropic Stresses
    Hindawi Publishing Corporation Journal of Gravity Volume 2013, Article ID 659605, 8 pages http://dx.doi.org/10.1155/2013/659605 Research Article Collapse of a Relativistic Self-Gravitating Star with Radial Heat Flux: Impact of Anisotropic Stresses Ranjan Sharma and Shyam Das Department of Physics, P.D. Women’s College, Jalpaiguri, West Bengal 735101, India Correspondence should be addressed to Ranjan Sharma; [email protected] Received 28 February 2013; Accepted 22 April 2013 Academic Editor: Sergei Odintsov Copyright © 2013 R. Sharma and S. Das. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We develop a simple model for a self-gravitating spherically symmetric relativistic star which begins to collapse from an initially static configuration by dissipating energy in the form of radial heat flow. We utilize the model to show how local anisotropy affects the collapse rate and thermal behavior of gravitationally evolving systems. 1. Introduction and Santos [5] formulated the junction conditions joining the interior space time of the collapsing object to the Vaidya In cosmology and astrophysics, there exist many outstanding exterior metric [4]. These developments have enabled many issues relating to a dynamical system collapsing under the investigators to construct realistic models of gravitationally influence of its own gravity. In view of Cosmic Censorship evolving systems and also to analyze critically relevance of Conjecture, the general relativistic prediction is that such a various factors such as shear, density inhomogeneity, local collapse must terminate into a space-time singularity covered anisotropy, electromagnetic field, viscosity, and so forth, on under its event horizon though there are several counter the physical behaviour of collapsing bodies [6–52].
    [Show full text]
  • Arxiv:Hep-Th/0404161V2 1 Nov 2004
    Cosmological perturbations from braneworld inflation with a Gauss-Bonnet term Jean-Francois Dufaux1, James E. Lidsey2, Roy Maartens3, M Sami4 1LPT, Universit´ede Paris-Sud, 91405 Orsay, France 2Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, London E1 4NS, UK 3Institute of Cosmology & Gravitation, University of Portsmouth, Portsmouth PO1 2EG, UK 4Inter-University Centre for Astronomy & Astrophysics, Pune, India (Dated: February 1, 2008) Braneworld inflation is a phenomenology related to string theory that describes high-energy mod- ifications to general relativistic inflation. The observable universe is a braneworld embedded in 5-dimensional anti de Sitter spacetime. When the 5-dimensional action is Einstein-Hilbert, we have a Randall-Sundrum type braneworld. The amplitude of tensor and scalar perturbations from in- flation is strongly increased relative to the standard results, although the ratio of tensor to scalar amplitudes still obeys the standard consistency relation. If a Gauss-Bonnet term is included in the action, as a high-energy correction motivated by string theory, we show that there are important changes to the Randall-Sundrum case. We give an exact analysis of the tensor perturbations. They satisfy the same wave equation and have the same spectrum as in the Randall-Sundrum case, but the Gauss-Bonnet change to the junction conditions leads to a modified amplitude of gravitational waves. The amplitude is no longer monotonically increasing with energy scale, but decreases asymp- totically after an initial rise above the standard level. Using an approximation that neglects bulk effects, we show that the amplitude of scalar perturbations has a qualitatively similar behaviour to the tensor amplitude.
    [Show full text]
  • Emili Elizalde. Perspectives on His Life and Work
    Emili Elizalde. Perspectives on his Life and Work Sebastia` Xambo´ Abstract The goal of this paper is to present a broad picture of Emili1 Elizalde’s unfolding as a person and as a researcher in physics and in mathematics. In addition to biographical information, we include his answers to a number of questions on his experience as a researcher and his role as a leading figure in his fields of expertise. 1 Prelude The “Facultat de Matematiques` i Estad´ıstica” (FME) of the “Universitat Politecnica` de Catalunya” (UPC) dedicated the academic year 2003-2004 to Henri Poincare.´ This started a practice that was followed by Albert Einstein (2004-2005), Carl F. Gauss (2005-2006), Leonhard Euler (2006-2007), Bernhard Riemann (2007-2008) and Emmy Noether (2008-2009). At the end of each of these years, the FME pub- lished a volume with the lectures delivered by the invited speakers (see [10] for more details).2 All these names were on top of the mathematics and the physics of their times and thus it should not be a surprise, especially by those that know him, that Emili Elizalde was one of the very few that were invited twice. The first time was for the Einstein year and the second time for the Riemann year. The titles of the lectures he delivered were, respectively, On the cosmological constant, the vacuum energy, and divergent series and Riemann and Physics (see [1, 2]). The close relation of these lectures with the topics of this symposium are obvious in the case of the first lecture.
    [Show full text]
  • Book of Abstracts
    BOOK OF ABSTRACTS 10th MATHEMATICAL PHYSICS MEETING: School and Conference on Modern Mathematical Physics 9 { 14 September 2019, Belgrade, Serbia www.mphys10.ipb.ac.rs Organizers 3 Organizers Institute of Physics (University of Belgrade) Belgrade, Serbia Faculty of Mathematics (University of Belgrade) Belgrade, Serbia Mathematical Institute (Serbian Academy of Sciences and Arts) Belgrade, Serbia Faculty of Science (University of Kragujevac) Kragujevac, Serbia Co-organizers Institute of Nuclear Sciences \Vinˇca" (University of Belgrade) Belgrade, Serbia Institute of Physics (University of Kragujevac) Kragujevac, Serbia Faculty of Physics (University of Belgrade) Belgrade, Serbia Faculty of Sciences (University of Novi Sad) Novi Sad, Serbia School of Electrical Engineering (University of Belgrade) Belgrade, Serbia Southeastern European Network in Mathematical and Theoretical Physics (SEENET-MTP) Nis, Serbia 4 Sponsors and media partners Sponsors Ministry of Education, Science and Technological Development, Serbia Telekom Srbija Open Access Journal \Symmetry" (MDPI, Switzerland) Media partner Open Access Journal \Entropy" (MDPI, Switzerland) Committees 5 International Advisory Committee Ignatios Antoniadis (Paris, France) Irina Arefeva (Moscow, Russia) Milutin Blagojevi´c(Belgrade, Serbia) Loriano Bonora (Trieste, Italy) Martin Cederwall (Goteborg, Sweden) Branislav Cvetkovi´c(Belgrade, Serbia) Marija Dimitrijevi´c Ciri´c(Belgrade,´ Serbia) Nemanja Kaloper (Davis, USA) Dord¯e- Mini´c(Blacksburg, USA) Viatcheslav Mukhanov (Munich, Germany)
    [Show full text]
  • Cosmic Acceleration: Past and Present
    COSMIC ACCELERATION: PAST AND PRESENT A Dissertation Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Nishant Agarwal May 2011 c 2011 Nishant Agarwal ALL RIGHTS RESERVED COSMIC ACCELERATION: PAST AND PRESENT Nishant Agarwal, Ph.D. Cornell University 2011 Our Universe has an exciting history of accelerated expansion. Following its in- ception in an event known as the big bang, the Universe underwent a phase of exponential expansion called inflation. Although precise observations of the cos- mic microwave background (CMB) radiation and large-scale structure support the inflationary paradigm, the absence of a firm physical mechanism for inflation has led to a plethora of theoretical embarkments attempting to understand its genesis. Inflation lasted only for a fraction of a second, but observations suggest that thir- teen billion years after inflation, the Universe began accelerating once again. This acceleration, which continues till date, is attributed to a mysterious component, dubbed dark energy, that fills up our Universe and accounts for almost 73% of the total energy density in the Universe. In this thesis we study and develop models of inflation and dark energy, in the light of current observations. We begin, in Chapter 1, with a detailed introduction to cosmic acceleration, and discuss various models of inflation and dark energy that have been studied in the literature in the recent years. In Chapter 2, we discuss how a hierarchy of Hubble flow parameters, extended to include the evolution of the inflationary sound speed, can be applied to compare a general, single-field inflationary action with cosmological observational data.
    [Show full text]
  • Del Big Bang Al Futur De L'univers
    Institute of Space Sciences On the concept of Bing Bang and a renormalization group improved, unified accelerating scenario Emilio Elizalde Hiroshima University, Aug 22, 2017 Name or Title or Xtra Institute of Space Sciences CONTENTS What’s the Big Bang? ̶ Not what popular sources say … The Universe expands (Lemaître, Hubble, …) Fred Hoyle Big Bang ! Inflation! The Big Bang Singularity: Singularity Theorems (HP, BGV) Expansion accelerates new singularities RG improved, unified accelerating scenario Name or Title or Xtra Seminar Hiroshima, Aug 2017 Facts (few of them rather surprising...) • Adam Riess, NP 2011, at Starmus (Tenerife), about Hubble: • “Hubble obtained the distances and redshifts of distant nebulae…” • “Hubble discovered that the Universe was expanding…” • No mention to Vesto Slipher, an extraordinary astronomer • Brian Schmidt, NP 2011, at Starmus (Tenerife) & Lisa Randall, Harvard U, in Barcelona, about Einstein: SHOES- • “Einstein was the first to think about the possibility of a ‘dark energy’…” Supernovae • No mention to Fritz Zwicky, another extraordinary astronomer • Zwicky discovered dark matter in the early 1930s while studying how galaxies move within the Coma Cluster • He was the first to postulate and use nebulae as gravitational lenses (1937) • How easily* brilliant astronomers get dismissed • How easily* scientific myths arise *in few decades Table 1: Distances in Mpc of spiral nebulae published by E Hubble in 1929 Table 1: Radial velocities in km/s of 25 spiral nebulae published by VM Slipher in 1917 Institute of Space Sciences Hubble’s Law At large scale, the dominant movement of our Universe is dictated by the law: V = Ho D Ho = (67.8 +/- 0.9) km/s/Mpc [500 Hubble, 1929] Interpretation ! 1.
    [Show full text]
  • Cosmological Perturbations from Braneworld Inflation with a Gauss
    Cosmological perturbations from braneworld inflation with a Gauss-Bonnet term Jean-Francois Dufaux1, James E. Lidsey2, Roy Maartens3, M Sami4 1LPT, Universit´ede Paris-Sud, 91405 Orsay, France 2Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, London E1 4NS, UK 3Institute of Cosmology & Gravitation, University of Portsmouth, Portsmouth PO1 2EG, UK 4Inter-University Centre for Astronomy & Astrophysics, Pune, India (Dated: October 29, 2018) Braneworld inflation is a phenomenology related to string theory that describes high-energy mod- ifications to general relativistic inflation. The observable universe is a braneworld embedded in 5-dimensional anti de Sitter spacetime. When the 5-dimensional action is Einstein-Hilbert, we have a Randall-Sundrum type braneworld. The amplitude of tensor and scalar perturbations from in- flation is strongly increased relative to the standard results, although the ratio of tensor to scalar amplitudes still obeys the standard consistency relation. If a Gauss-Bonnet term is included in the action, as a high-energy correction motivated by string theory, we show that there are important changes to the Randall-Sundrum case. We give an exact analysis of the tensor perturbations. They satisfy the same wave equation and have the same spectrum as in the Randall-Sundrum case, but the Gauss-Bonnet change to the junction conditions leads to a modified amplitude of gravitational waves. The amplitude is no longer monotonically increasing with energy scale, but decreases asymp- totically after an initial rise above the standard level. Using an approximation that neglects bulk effects, we show that the amplitude of scalar perturbations has a qualitatively similar behaviour to the tensor amplitude.
    [Show full text]