DOCSLIB.ORG

New Physics on the Horizon? Testing the Nature of Dark Compact Objects

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
New Physics on the Horizon? Testing the Nature of Dark Compact Objects Copernicus Webinar – copernicuswebinar.com – Mar 2nd, 2021 New physics on the horizon? Testing the nature of dark compact o#$ects Credits: G. Raposo Kerr Fuzzball ,-ianchi+ PR/ 21012 Paolo Pani Sapienza University of Rome & INFN Roma1 There’s a crackhttps%//web.uniroma1.it/gm in everything – that’s how nthe li ht gets in. "eonard Cohen http://www.Dar"GRA.org -lack holes are now everywhere3 4hy testing the -5 picture? #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 4hy? Are there compact objects other than black holes and neutron stars? /I)6&7irgo mass8gap events? Supermassive BH seeds? 9(ar") matter compact o#$ects? (e'g' #oson/a;ion stars: #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 4hy? Are there compact objects other than black holes and neutron stars? /I)6&7irgo mass8gap events? Supermassive BH seeds? 9(ar") matter compact o#$ects? (e'g' #oson/a;ion stars: Observational signatures of quantum BHs? 9if not now, when': Information loss, singularities, +a chy horizons… New physics at the horizon (e'g' >rewalls, nonlocality: ,*lmheri.< Gi!!ings.< 01108011?2 Regular< horizonless compact o#$ects (e'g' f zz#alls) ,Math r.< -ena.< -ianchi.< Gi sto.< =2 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 4hy? Are there compact objects other than black holes and neutron stars? /I)6&7irgo mass8gap events? Supermassive BH seeds? 9(ar") matter compact o#$ects? (e'g' #oson/a;ion stars: Observational signatures of quantum BHs? 9if not now, when': Information loss, singularities, +a chy horizons… New physics at the horizon (e'g' >rewalls, nonlocality: ,*lmheri.< Gi!!ings.< 01108011?2 Regular< horizonless compact o#$ects (e'g' f zz#alls) ,Math r.< -ena.< -ianchi.< Gi sto.< =2 uantifying the "BH#ness” across mass ranges 9e.g' -ayesian mo!el selection: #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 4hy? Are there compact objects other than black holes and neutron stars? /I)6&7irgo mass8gap events? Supermassive BH seeds? 9(ar") matter compact o#$ects? (e'g' #oson/a;ion stars: Observational signatures of quantum BHs? 9if not now, when': Information loss, singularities, +a chy horizons… New physics at the horizon (e'g' >rewalls, nonlocality: ,*lmheri.< Gi!!ings.< 01108011?2 Regular< horizonless compact o#$ects (e'g' f zz#alls) ,Math r.< -ena.< -ianchi.< Gi sto.< =2 uantifying the "BH#ness” across mass ranges 9e.g' -ayesian mo!el selection: 6#servations of exotic compact o#$ects 9A+6s) wo l! imply new physics & new matter #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 The zoo of ECOs %olutions to GR %olutions to modified gravit! (ith exotic matter sources 9e.g. fuzzbal!s/microstates, 2$2 ho!es, 9e. anisotropic stars, boson stars, superspinars, wormho!es: axion stars, ravastars, wormholes: No sharp !istinction in some cases Some A+Os reB ire mo!i>e! gravity only in the interior & close to the horizon C assuming )R in the e;terior is often a goo! appro;' Some mo!els are phenomenological (formation, !ynamics, sta#ility?) 5ere we foc s on )4 phenomenology agnostica!!y ,Cardoso , -ani. /iving Rev Relativ 012345 1167 for EC6 mo!eling< constraints, an! details] #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the sha!es of darkness #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the shades of darkness Compactness #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the shades of darkness D antifying #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 $ March Webinar #. #ani $New physics the Copernicus hori&on' on ReEectivity Compactness D antifying the shades of darkness D antifying #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 $ March Webinar #. #ani $New physics the Copernicus hori&on' on -lac" hole -lac" ReEectivity Compactness D antifying the sha!es of darkness D antifying #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 $ March Webinar #. #ani $New physics the Copernicus hori&on' on -lac" hole -lac" ReEectivity Compactness FSmallcompactness 9 e.g. boson stars e.g.boson Noa#sorption : D antifying the sha!es of darkness y t i FSmall compactness v i t No a#sorption c e 9e.g. boson stars: E e R FSmall compactness /arge a#sorption 9e. diffuse (uzzba!!s: Compactness -lac" hole #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the sha!es of darkness y t i /arge compactness FSmall compactness v i t No absorption No a#sorption c e 9e. ravastars: 9e.g. boson stars: E e R FSmall compactness /arge a#sorption 9e. diffuse (uzzba!!s: Compactness -lac" hole #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the sha!es of darkness y t i /arge compactness FSmall compactness v i t No absorption No a#sorption c e 9e. ravastars: 9e.g. boson stars: E e R /arge compactness FSmall compactness /arge absorption /arge a#sorption 9e. ti ht (uzzba!!s: 9e. diffuse (uzzba!!s: Compactness -lac" hole #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the sha!es of darkness Light ring y t i /arge compactness FSmall compactness v i t No absorption No a#sorption c e 9e. ravastars: 9e.g. boson stars: E e R /arge compactness FSmall compactness /arge absorption /arge a#sorption 9e. ti ht (uzzba!!s: 9e. diffuse (uzzba!!s: Compactness -lac" hole #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 D antifying the sha!es of darkness Light ring y t i /arge compactness FSmall compactness v i t No absorption No a#sorption c e 5ow9e. ravastars !o current: 9ande.g. boson f tstars re: E e R o#servations constrain this parameter space? /arge compactness FSmall compactness /arge absorption /arge a#sorption 9e. ti ht (uzzba!!s: 9e. diffuse (uzzba!!s: Compactness -lac" hole #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 * compass to navigate the E+O atlas #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 Eva!ing - ch!hal G1%-oson stars Liebling & Palenz ela Living Rev. Rel' 01< 9011?:< I 4ell8motivate! and consistent: Self8gravitating solutions to )R + (comple;) #oson @a;' mass and compactness depend on self8interactions Spinning (scalar) #oson stars are unstable nless strongly interacting ,Sanchis8) al+ PRL 011H< Siemonsen8East PR( 01012 Flight-ring ,Siemonsen & East< Phys' Rev. ( 11J 90101:2 Strong interactions give rise to m ltiple stable #ranches ,) erra< @acedo< PP< K+*P 011H2 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 Evading Buchdhal #2: anisotropic stars Raposo+, Phys' Rev. D 99, 104050 (2019) +ovariant framewor" for anisotropic py tro iso E i!s in )R, ready for J.1 sim lations an +onsistent pro;y for ltracompact ob$ects Satisfy 4A+ an! SA+; highly8 anisotropic con>g rations violate (A+ (isplay all A+6 typical phenomenology #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 Ava!ing B ch!hal #3: fuzz#alls F zzball paradigm: classical B5s are ensembles of a huge n m#er of regular< horizonless, microstate geometries ,/ nin+ 0111< Math r 011I.< -ena.< -ianchi.< Gi sto.< '''2 -5 entropy e;plained #y the num#er of microstates' -5 entropy accounte! for in special cases ,Strominger 1HHN< 5orowitz 1HHN< Mal!acena 1HH?2 BH 9/ow8energy truncations of) string theory admits huge families of solutions ,-ena+ 011?< 011I8011?2 Pros: well motivate!< mass is free parameter +ons: only nearly e;tremal charged BHs so far< complicated Open issues: measurement problem (typical vs atypical states, averaging?:< phenomenology ,@ayerson 01012 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 Imaging the horizon? Ascape angle F 69ε) Roun!8trip time F H@ +ar!oso & PP< Nature *stronomy 90117) A@ tests when εC1 are very challenging ,*#ramowicz+ 90110:2 A;istence of a light ring is a strong !iscriminator #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 The imitation game -5 -oson star -5 Proca star Vincent., CQG (2016) Herdeiro+, 2102.01703 Degeneracy with spin< !istance, accretion mo!el, emissivity? @ore compact A+Os woul! imitate the -5 #etter Tests #ase! on sha!ows can constrain ,A5T 011H< Car!oso8Pani 011H< 7ol"el+ 01012 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 5ow a#o t accretion? #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 5ow a#o t accretion? #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 5ow a#o t accretion? @/RF1'1HP @/RF1'1?I D antitative !ifferences ! e to matter acc m lating in the interior ,Olivares+ @NR*S 01012 @ore compact ob$ects with light rings might #e har!er to !istinguish ,+ar!oso< ( B e, Foschi 90101:2 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 5ow a#o t accretion? *ssuming thermal eB ili#ri m an! har! surface yiel!s m ch tighter constraints ,-ro!eric"8Narayan CQG 011?2 This stringent constraint is evade! if the ob$ect has $ st a tiny absorption ,Car#allo8R #io.< Phys'Rev.( HP 10 10L11H 9011P:2 #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 )48based tests of ECOs Sli!e concept #y T. 5in!erer an! *' @aselli #. #ani $ New physics on the hori&on' Copernicus Webinar $ March 2021 ECO spectroscopy Prompt ringdo(n: superposition of B asinormal mo!es 9QN@s) ,e'g' Qo""otas & Schmi!t (1HHH:< -erti< Car!oso< Starinets 9011H:2 J)&/IS* C 69100-1111: events/yr allowing for -5 spectroscopy ,-erti+ 9011N:2 6vertones also important C m ltimo!e/m ltitone analysis? ,Gieser+ 011H< Isi+ 011H< -hagwat+ 0101< Ota8Chirenti 0101< Forteza+ 01012 A+6 smoking g ns in the prompt ringdown 9share! with mo!i>e! gravity:% Shift of the entire DN@ spectr m A;tra ringdown mo!es (e'g'< e;tra polarizations, matter mo!es) C amplit !es? Isospectrality #rea"ing Ring!own parametrizations suRcient for n ll8hypothesis tests ,Mei!am+ 9011L:< Glampedakis+ 9011?:< Car llo+ 9011P:< Car!oso.
Load more

Recommended publications
  • Pulsar Scattering, Lensing and Gravity Waves
    Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary Pulsar Scattering, Lensing and Gravity Waves Ue-Li Pen, Lindsay King, Latham Boyle CITA Feb 15, 2012 U. Pen Pulsar Scattering, Lensing and Gravity Waves Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary Overview I Pulsar Scattering I VLBI ISM holography, distance measures I Enhanced Pulsar Timing Array gravity waves I fuzzballs U. Pen Pulsar Scattering, Lensing and Gravity Waves Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary Pulsar Scattering I Pulsars scintillate strongly due to ISM propagation I Lens of geometric size ∼ AU I Can be imaged with VLBI (Brisken et al 2010) I Deconvolved by interstellar holography (Walker et al 2008) U. Pen Pulsar Scattering, Lensing and Gravity Waves Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary Scattering Image Data from Brisken et al, Holographic VLBI. U. Pen Pulsar Scattering, Lensing and Gravity Waves Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary ISM enigma −8 I Scattering angle observed mas, 10 rad. I Snell's law: sin(θ1)= sin(θ2) = n2=n1 −12 I n − 1 ∼ 10 . I 4 orders of magnitude mismatch. U. Pen Pulsar Scattering, Lensing and Gravity Waves Introduction Convergent Plasma Lenses Gravity Waves Black Holes/Fuzzballs Summary Possibilities I turbulent ISM: sum of many small scatters. Cannot explain discrete images. I confinement problem: super mini dark matter halos, cosmic strings? I Geometric alignment: Goldreich and Shridhar (2006) I Snell's law at grazing incidence: ∆α = (1 − n2=n1)/α I grazing incidence is geometry preferred at 2-D structures U.
    [Show full text]
  • Exploring Pulsars
    High-energy astrophysics Explore the PUL SAR menagerie Astronomers are discovering many strange properties of compact stellar objects called pulsars. Here’s how they fit together. by Victoria M. Kaspi f you browse through an astronomy book published 25 years ago, you’d likely assume that astronomers understood extremely dense objects called neutron stars fairly well. The spectacular Crab Nebula’s central body has been a “poster child” for these objects for years. This specific neutron star is a pulsar that I rotates roughly 30 times per second, emitting regular appar- ent pulsations in Earth’s direction through a sort of “light- house” effect as the star rotates. While these textbook descriptions aren’t incorrect, research over roughly the past decade has shown that the picture they portray is fundamentally incomplete. Astrono- mers know that the simple scenario where neutron stars are all born “Crab-like” is not true. Experts in the field could not have imagined the variety of neutron stars they’ve recently observed. We’ve found that bizarre objects repre- sent a significant fraction of the neutron star population. With names like magnetars, anomalous X-ray pulsars, soft gamma repeaters, rotating radio transients, and compact Long the pulsar poster child, central objects, these bodies bear properties radically differ- the Crab Nebula’s central object is a fast-spinning neutron star ent from those of the Crab pulsar. Just how large a fraction that emits jets of radiation at its they represent is still hotly debated, but it’s at least 10 per- magnetic axis. Astronomers cent and maybe even the majority.
    [Show full text]
  • Neutron Stars
    Chandra X-Ray Observatory X-Ray Astronomy Field Guide Neutron Stars Ordinary matter, or the stuff we and everything around us is made of, consists largely of empty space. Even a rock is mostly empty space. This is because matter is made of atoms. An atom is a cloud of electrons orbiting around a nucleus composed of protons and neutrons. The nucleus contains more than 99.9 percent of the mass of an atom, yet it has a diameter of only 1/100,000 that of the electron cloud. The electrons themselves take up little space, but the pattern of their orbit defines the size of the atom, which is therefore 99.9999999999999% Chandra Image of Vela Pulsar open space! (NASA/PSU/G.Pavlov et al. What we perceive as painfully solid when we bump against a rock is really a hurly-burly of electrons moving through empty space so fast that we can't see—or feel—the emptiness. What would matter look like if it weren't empty, if we could crush the electron cloud down to the size of the nucleus? Suppose we could generate a force strong enough to crush all the emptiness out of a rock roughly the size of a football stadium. The rock would be squeezed down to the size of a grain of sand and would still weigh 4 million tons! Such extreme forces occur in nature when the central part of a massive star collapses to form a neutron star. The atoms are crushed completely, and the electrons are jammed inside the protons to form a star composed almost entirely of neutrons.
    [Show full text]
  • A Conceptual Model for the Origin of the Cutoff Parameter in Exotic Compact Objects
    S S symmetry Article A Conceptual Model for the Origin of the Cutoff Parameter in Exotic Compact Objects Wilson Alexander Rojas Castillo 1 and Jose Robel Arenas Salazar 2,* 1 Departamento de Física, Universidad Nacional de Colombia, Bogotá UN.11001, Colombia; [email protected] 2 Observatorio Astronómico Nacional, Universidad Nacional de Colombia, Bogotá UN.11001, Colombia * Correspondence: [email protected] Received: 30 October 2020; Accepted: 30 November 2020 ; Published: 14 December 2020 Abstract: A Black Hole (BH) is a spacetime region with a horizon and where geodesics converge to a singularity. At such a point, the gravitational field equations fail. As an alternative to the problem of the singularity arises the existence of Exotic Compact Objects (ECOs) that prevent the problem of the singularity through a transition phase of matter once it has crossed the horizon. ECOs are characterized by a closeness parameter or cutoff, e, which measures the degree of compactness of the object. This parameter is established as the difference between the radius of the ECO’s surface and the gravitational radius. Thus, different values of e correspond to different types of ECOs. If e is very big, the ECO behaves more like a star than a black hole. On the contrary, if e tends to a very small value, the ECO behaves like a black hole. It is considered a conceptual model of the origin of the cutoff for ECOs, when a dust shell contracts gravitationally from an initial position to near the Schwarzschild radius. This allowed us to find that the cutoff makes two types of contributions: a classical one governed by General Relativity and one of a quantum nature, if the ECO is very close to the horizon, when estimating that the maximum entropy is contained within the material that composes the shell.
    [Show full text]
  • R-Process Elements from Magnetorotational Hypernovae
    r-Process elements from magnetorotational hypernovae D. Yong1,2*, C. Kobayashi3,2, G. S. Da Costa1,2, M. S. Bessell1, A. Chiti4, A. Frebel4, K. Lind5, A. D. Mackey1,2, T. Nordlander1,2, M. Asplund6, A. R. Casey7,2, A. F. Marino8, S. J. Murphy9,1 & B. P. Schmidt1 1Research School of Astronomy & Astrophysics, Australian National University, Canberra, ACT 2611, Australia 2ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia 3Centre for Astrophysics Research, Department of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield, AL10 9AB, UK 4Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 5Department of Astronomy, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden 6Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85741 Garching, Germany 7School of Physics and Astronomy, Monash University, VIC 3800, Australia 8Istituto NaZionale di Astrofisica - Osservatorio Astronomico di Arcetri, Largo Enrico Fermi, 5, 50125, Firenze, Italy 9School of Science, The University of New South Wales, Canberra, ACT 2600, Australia Neutron-star mergers were recently confirmed as sites of rapid-neutron-capture (r-process) nucleosynthesis1–3. However, in Galactic chemical evolution models, neutron-star mergers alone cannot reproduce the observed element abundance patterns of extremely metal-poor stars, which indicates the existence of other sites of r-process nucleosynthesis4–6. These sites may be investigated by studying the element abundance patterns of chemically primitive stars in the halo of the Milky Way, because these objects retain the nucleosynthetic signatures of the earliest generation of stars7–13.
    [Show full text]
  • Magnetars: Explosive Neutron Stars with Extreme Magnetic Fields
    Magnetars: explosive neutron stars with extreme magnetic fields Nanda Rea Institute of Space Sciences, CSIC-IEEC, Barcelona 1 How magnetars are discovered? Soft Gamma Repeaters Bright X-ray pulsars with 0.5-10keV spectra modelled by a thermal plus a non-thermal component Anomalous X-ray Pulsars Bright X-ray transients! Transients No more distinction between Anomalous X-ray Pulsars, Soft Gamma Repeaters, and transient magnetars: all showing all kind of magnetars-like activity. Nanda Rea CSIC-IEEC Magnetars general properties 33 36 Swift-XRT COMPTEL • X-ray pulsars Lx ~ 10 -10 erg/s INTEGRAL • strong soft and hard X-ray emission Fermi-LAT • short X/gamma-ray flares and long outbursts (Kuiper et al. 2004; Abdo et al. 2010) • pulsed fractions ranging from ~2-80 % • rotating with periods of ~0.3-12s • period derivatives of ~10-14-10-11 s/s • magnetic fields of ~1013-1015 Gauss (Israel et al. 2010) • glitches and timing noise (Camilo et al. 2006) • faint infrared/optical emission (K~20; sometimes pulsed and transient) • transient radio pulsed emission (see Woods & Thompson 2006, Mereghetti 2008, Rea & Esposito 2011 for a review) Nanda Rea CSIC-IEEC How magnetar persistent emission is believed to work? • Magnetars have magnetic fields twisted up, inside and outside the star. • The surface of a young magnetar is so hot that it glows brightly in X-rays. • Magnetar magnetospheres are filled by charged particles trapped in the twisted field lines, interacting with the surface thermal emission through resonant cyclotron scattering. (Thompson, Lyutikov & Kulkarni 2002; Fernandez & Thompson 2008; Nobili, Turolla & Zane 2008a,b; Rea et al.
    [Show full text]
  • Stellar Death: White Dwarfs, Neutron Stars, and Black Holes
    Stellar death: White dwarfs, Neutron stars & Black Holes Content Expectaions What happens when fusion stops? Stars are in balance (hydrostatic equilibrium) by radiation pushing outwards and gravity pulling in What will happen once fusion stops? The core of the star collapses spectacularly, leaving behind a dead star (compact object) What is left depends on the mass of the original star: <8 M⦿: white dwarf 8 M⦿ < M < 20 M⦿: neutron star > 20 M⦿: black hole Forming a white dwarf Powerful wind pushes ejects outer layers of star forming a planetary nebula, and exposing the small, dense core (white dwarf) The core is about the radius of Earth Very hot when formed, but no source of energy – will slowly fade away Prevented from collapsing by degenerate electron gas (stiff as a solid) Planetary nebulae (nothing to do with planets!) THE RING NEBULA Planetary nebulae (nothing to do with planets!) THE CAT’S EYE NEBULA Death of massive stars When the core of a massive star collapses, it can overcome electron degeneracy Huge amount of energy BAADE ZWICKY released - big supernova explosion Neutron star: collapse halted by neutron degeneracy (1934: Baade & Zwicky) Black Hole: star so massive, collapse cannot be halted SN1006 1967: Pulsars discovered! Jocelyn Bell and her supervisor Antony Hewish studying radio signals from quasars Discovered recurrent signal every 1.337 seconds! Nicknamed LGM-1 now called PSR B1919+21 BRIGHTNESS TIME NATURE, FEBRUARY 1968 1967: Pulsars discovered! Beams of radiation from spinning neutron star Like a lighthouse Neutron
    [Show full text]
  • Probing the Nuclear Equation of State from the Existence of a 2.6 M Neutron Star: the GW190814 Puzzle
    S S symmetry Article Probing the Nuclear Equation of State from the Existence of a ∼2.6 M Neutron Star: The GW190814 Puzzle Alkiviadis Kanakis-Pegios †,‡ , Polychronis S. Koliogiannis ∗,†,‡ and Charalampos C. Moustakidis †,‡ Department of Theoretical Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; [email protected] (A.K.P.); [email protected] (C.C.M.) * Correspondence: [email protected] † Current address: Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. ‡ These authors contributed equally to this work. Abstract: On 14 August 2019, the LIGO/Virgo collaboration observed a compact object with mass +0.08 2.59 0.09 M , as a component of a system where the main companion was a black hole with mass ∼ − 23 M . A scientific debate initiated concerning the identification of the low mass component, as ∼ it falls into the neutron star–black hole mass gap. The understanding of the nature of GW190814 event will offer rich information concerning open issues, the speed of sound and the possible phase transition into other degrees of freedom. In the present work, we made an effort to probe the nuclear equation of state along with the GW190814 event. Firstly, we examine possible constraints on the nuclear equation of state inferred from the consideration that the low mass companion is a slow or rapidly rotating neutron star. In this case, the role of the upper bounds on the speed of sound is revealed, in connection with the dense nuclear matter properties. Secondly, we systematically study the tidal deformability of a possible high mass candidate existing as an individual star or as a component one in a binary neutron star system.
    [Show full text]
  • Neutron Stars & Black Holes
    Introduction ? Recall that White Dwarfs are the second most common type of star. ? They are the remains of medium-sized stars - hydrogen fused to helium Neutron Stars - failed to ignite carbon - drove away their envelopes to from planetary nebulae & - collapsed and cooled to form White Dwarfs ? The more massive a White Dwarf, the smaller its radius Black Holes ? Stars more massive than the Chandrasekhar limit of 1.4 solar masses cannot be White Dwarfs Formation of Neutron Stars As the core of a massive star (residual mass greater than 1.4 ?Supernova 1987A solar masses) begins to collapse: (arrow) in the Large - density quickly reaches that of a white dwarf Magellanic Cloud was - but weight is too great to be supported by degenerate the first supernova electrons visible to the naked eye - collapse of core continues; atomic nuclei are broken apart since 1604. by gamma rays - Almost instantaneously, the increasing density forces freed electrons to absorb electrons to form neutrons - the star blasts away in a supernova explosion leaving behind a neutron star. Properties of Neutron Stars Crab Nebula ? Neutrons stars predicted to have a radius of about 10 km ? In CE 1054, Chinese and a density of 1014 g/cm3 . astronomers saw a ? This density is about the same as the nucleus supernova ? A sugar-cube-sized lump of this material would weigh 100 ? Pulsar is at center (arrow) million tons ? It is very energetic; pulses ? The mass of a neutron star cannot be more than 2-3 solar are detectable at visual masses wavelengths ? Neutron stars are predicted to rotate very fast, to be very ? Inset image taken by hot, and have a strong magnetic field.
    [Show full text]
  • A Brief Overview of Research Areas in the OSU Physics Department
    A brief overview of research areas in the OSU Physics Department Physics Research Areas • Astrophysics & Cosmology • Atomic, Molecular, and Optical Physics • Biophysics • Cold Atom Physics (theory) • Condensed Matter Physics • High Energy Physics • Nuclear Physics • Physics Education Research (A Scientific Approach to Physics Education) Biophysics faculty Michael Poirier - Dongping Zhong - Ralf Bundschuh -Theory Experiment Experiment C. Jayaprakash - Theory Comert Kural (Biophysics since 2001) Experiment Biophysics Research Main theme: Molecular Mechanisms Behind Important Biological Functions Research areas: •chromosome structure and function •DNA repair •processing of genetic information •genetic regulatory networks •ultrafast protein dynamics •interaction of water with proteins •RNA structure and function Experimental Condensed Matter Physics Rolando Valdes Aguilar THz spectroscopy of quantum materials P. Chris Hammel Nanomagnetism and spin-electronics, high spatial resolution and high sensitivity scanned Roland Kawakami probe magnetic resonance imaging Spin-Based Electronics and Nanoscale Magnetism Leonard Brillson Semiconductor surfaces and interfaces, complex oxides, next generation electronics, high permittivity dielectrics, solar cells, biological Fengyuan Yang sensors Magnetism and magnetotransport in complex oxide epitaxial films; metallic multilayers; spin Jon Pelz dynamics/ transport in semiconductor nanowires Spatial and energy-resolved studies of contacts, deep-level defects, films and buried interfaces in oxides and semiconductors; spin injection Ezekiel Johnston-Halperin into semiconductors. Nanoscience, magnetism, spintronics, molecular/ organic electronics, complex oxides. Studies of Thomas Lemberger matter at nanoscopic length scales Magnetic and electronic properties of high temperature superconductors and other Jay Gupta oxides; thin film growth by coevaporation and LT UHV STM combined with optical probes; studies sputtering; single crystal growth. of interactions of atoms and molecules on surfaces structures built with atomic precision R.
    [Show full text]
  • Blasts from the Past Historic Supernovas
    BLASTS from the PAST: Historic Supernovas 185 386 393 1006 1054 1181 1572 1604 1680 RCW 86 G11.2-0.3 G347.3-0.5 SN 1006 Crab Nebula 3C58 Tycho’s SNR Kepler’s SNR Cassiopeia A Historical Observers: Chinese Historical Observers: Chinese Historical Observers: Chinese Historical Observers: Chinese, Japanese, Historical Observers: Chinese, Japanese, Historical Observers: Chinese, Japanese Historical Observers: European, Chinese, Korean Historical Observers: European, Chinese, Korean Historical Observers: European? Arabic, European Arabic, Native American? Likelihood of Identification: Possible Likelihood of Identification: Probable Likelihood of Identification: Possible Likelihood of Identification: Possible Likelihood of Identification: Definite Likelihood of Identification: Definite Likelihood of Identification: Possible Likelihood of Identification: Definite Likelihood of Identification: Definite Distance Estimate: 8,200 light years Distance Estimate: 16,000 light years Distance Estimate: 3,000 light years Distance Estimate: 10,000 light years Distance Estimate: 7,500 light years Distance Estimate: 13,000 light years Distance Estimate: 10,000 light years Distance Estimate: 7,000 light years Distance Estimate: 6,000 light years Type: Core collapse of massive star Type: Core collapse of massive star Type: Core collapse of massive star? Type: Core collapse of massive star Type: Thermonuclear explosion of white dwarf Type: Thermonuclear explosion of white dwarf? Type: Core collapse of massive star Type: Thermonuclear explosion of white dwarf Type: Core collapse of massive star NASA’s ChANdrA X-rAy ObServAtOry historic supernovas chandra x-ray observatory Every 50 years or so, a star in our Since supernovas are relatively rare events in the Milky historic supernovas that occurred in our galaxy. Eight of the trine of the incorruptibility of the stars, and set the stage for observed around 1671 AD.
    [Show full text]
  • Can We Observe Fuzzballs Or Firewalls?
    Can we observe fuzzballs or firewalls? Bin Guo1, Shaun Hampton2 and Samir D. Mathur3 Department of Physics The Ohio State University Columbus, OH 43210, USA Abstract In the fuzzball paradigm the information paradox is resolved because the black hole is replaced by an object with no horizon. One may therefore ask if observations can distinguish a traditional hole from a fuzzball. We find: (a) It is very difficult to reflect quanta off the surface of a fuzzball, mainly because geodesics starting near the horizon radius cannot escape to infinity unless their starting direction is very close to radial. (b) If infalling particles interact with the emerging radiation before they are engulfed by the horizon, then we say that we have a ‘firewall behavior’. We consider several types of interactions, but find no evidence for firewall behavior in any theory that obeys causality. (c) Photons with wavelengths larger than the black hole radius can be scattered off the emerging radiation, but a very small fraction of the backscattered photons will be able to escape back to infinity. arXiv:1711.01617v1 [hep-th] 5 Nov 2017 [email protected] [email protected] [email protected] 1 Introduction In the traditional picture of a black hole, all the mass resides at a central singularity, while the rest of spacetime is empty. In particular, the region around the horizon is in a vacuum state. But such a picture of the hole leads to the black hole information paradox [1]. In string theory, it appears that this paradox is avoided because the structure of the hole is radically different: the hole is described by a horizon sized fuzzball, with no horizon [2, 3].
    [Show full text]