-
20/07/2015, 09:00
-
Prof. Achim Kempf (PI/Waterloo)20/07/2015, 09:30
-
Prof. Luciano Rezzolla (ITP, Goethe University Frankfurt)20/07/2015, 10:00Gravitational collapse to a rotating black hole is a common and recurrent feature of the dynamics of compact stars. I will discuss several examples of this process and the implications they have in potentially explaining some of the most dramatic and puzzling processes in astrophysics.Go to contribution page
-
Prof. Horst Stöcker (FIAS & GSI)20/07/2015, 11:30SeniorsTalkPure SU_c Lattice Gauge Theory, LGT, predicts a strong first order phase transition from a deconfined glue plasma to a confined GlueBall fluid, at a critical temperature of T_c=270 MeV. QCD-transport calculations show that such pure gauge matter can be created for a fleeting moment in high multiplicity pp, pA and AA collisions at the LHC at CERN and at RHiC at BNL. Pure gauge matter is...Go to contribution page
-
Ali Seraj (IPM, Tehran, Iran)20/07/2015, 14:00StudentsWe construct the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy. Each element in the phase space is a geometry with SL(2,R)×U(1)d−3 Killing isometries which has vanishing SL(2,R) and constant U(1) charges. In four spacetime dimensions, the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra,...Go to contribution page
-
Mr Mattia Colombo (University of Nottingham)20/07/2015, 14:20StudentsWhen Lorentz symmetry is broken, defining the concept of Black Hole becomes highly non-trivial. In this talk I wish to discuss the problems related to such definition and introduce a way to define the causal structure and horizons for a manifold with a preferred foliation.Go to contribution page
-
Ms Marcela Cárdenas (Universidad de Concepción, Centro de Estudios Científicos)20/07/2015, 14:40StudentsWe present a Chern-Simons-like description of three-dimensional gravity with negative cosmological constant, where the matter source is a conformally coupled real scalar field. This description is based on a first-order action that provides a set of field equations equivalent to that derived from the usual second-order action. The system admits a rotating hairy black hole solution, which is...Go to contribution page
-
Andrea Giugno (University of Bologna)20/07/2015, 15:00StudentsWe study a corpuscular model of evaporating black holes consisting of a large number $N$ of self-confined bosons. The single-particle spectrum contains a discrete ground state of energy $m$ (corresponding to toy gravitons forming a black hole), and a gapless continuous spectrum (to accommodate for Hawking radiation with energy $\omega>m$). In particular, we consider each constituent in a...Go to contribution page
-
Dr Hui-Yiing Chang (University of South Carolina Sumter)20/07/2015, 16:00We examine a quintessence model with a modified exponential potential given by $V(\phi) = V_0(1 + e^{-\lambda \phi})$. We determine the evolution of the equation of state parameter, $w_\phi$, and the density parameter, $\Omega_\phi$, as a function of the scale factor. Our model, unlike quintessence with a standard exponential potential, can produce an acceptable accelerated expansion at late...Go to contribution page
-
Cristi Stoica (Horia Hulubei National Institute for Physics and Nuclear Engineering)20/07/2015, 16:20JuniorsSchwarzschild's solution is the soul of General Relativity (GR). It was found immediately after Einstein found his equation, and plays an essential role in the approximations that allow us to test GR in our solar system. Moreover, the most notable problems of GR, such as the occurrence of singularities and the information paradox, were found on the background provided by Schwarzschild's...Go to contribution page
-
Tigran Kalaydzhyan (Stony Brook University)20/07/2015, 16:40JuniorsWithin the general theory of relativity, the curvature of space-time is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high...Go to contribution page
-
Dr Tatsuo Azeyanagi (Ecole Normale Superieure)20/07/2015, 17:00In this presentation, I will revisit the Noether charge formulation of black hole entropy in the presence of gravitational Chern-Simons terms in higher dimensions. I will provide a manifestly covariant formulation of the differential Noether charge and prove the (generalized version of) black hole entropy formula for gravitational Chern-Simons terms proposed by Tachikawa. In the context of...Go to contribution page
-
Mirah Gary (Institute for Theoretical Physics, TU Wien)20/07/2015, 17:20JuniorsWorking in three dimensions, we introduce flat space spin-3 gravity in the presence of chemical potentials and discuss some applications to flat space cosmology solutions, their entropy, free energy and flat space orbifold singularity resolution. Our results include flat space Einstein gravity with chemical potentials as special case. We discover novel types of phase transitions between flat...Go to contribution page
-
Frans Pretorius21/07/2015, 09:00I will review what been learnt in recent years about the ultra-relativistic collision problem in classical general relativity. This area has connections to super-Planck scale particle collisions and the interaction of gravitational shock waves, and addresses questions pertinent to cosmic censorship, black hole formation and the hoop conjecture. I will also discuss some open questions and...Go to contribution page
-
Valeria Ferrari (Sapienza Rome)21/07/2015, 10:00It is known that black holes have no hair, which means that they are fully described by only three parameters: mass, spin and charge. Conversely, a neutron star may have a very rich multipole structure, and all information about this structure is supposed to be radiated away during the gravitational collapse. However, the transition from a fully hairy star to a bald black hole may not be so...Go to contribution page
-
Georgi Dvali (LMU, Arnold Sommerfeld Center)21/07/2015, 11:30We discuss physics of black hole information storage and processing in a quantum portrait according to which black hole is a loose bound-state of many soft gravitons at the quantum critical point, with characteristic Liapunov exponent responsible for the quantum instability and information scrambling. This picture sheds light at the microscopic origin of black hole entropy and also shows that...Go to contribution page
-
Supakchai Ponglertsakul21/07/2015, 14:00StudentsA charged scalar field can be used to extract energy from a charged black hole via superradiant scattering. A mirror-like or AdS boundary could lead the system to an instability. This is because the scalar fields are trapped outside the black hole and repeatedly amplified, there-fore ultimately the back-reaction on the black hole background will become non-negligible. A charged scalar field...Go to contribution page
-
Antonia Micol Frassino21/07/2015, 14:20StudentsI will talk about the effects of higher curvature corrections from Lovelock gravity on the phase structure of asymptotically AdS black holes, treating the cosmological constant as a thermodynamic pressure.Go to contribution page
-
Andrea Addazi (INFN)21/07/2015, 14:40We show how a system of $N>>1$ horizonless conic singularities, with average opening angle at the horizon $\langle \Theta \rangle=2\pi$, can effectively approximate the geometry and the entropy of a semiclassical black hole. We test what happen to in-going informations in such a system, with a simple gedanken experiment: we consider a plane wave function in-going in this system of N conic...Go to contribution page
-
Eugene Kur (University of California, Berkeley)21/07/2015, 15:00StudentsI will discuss multisymplectic geometry and its application to finite spacetime regions. This allows one to perform a 3+1 decomposition where the spatial slice need not be a Cauchy surface. I show how this can lead to a modification of the symplectic structure, Hamilton's principle function, and momentum maps (conserved charges). Such modifications are in the form of boundary terms which can...Go to contribution page
-
Sven Köppel (Frankfurt Institute for Advanced Sciences)21/07/2015, 15:20StudentsI will talk about the extension of general uncertainty principle (GUP) inspired black holes to the scenario of large spatial extradimensions (ADD).Go to contribution page
-
Roberto Casadio (Alma Mater Bologna University)21/07/2015, 16:00SeniorsWe propose to investigate the Cosmic Censorship Conjecture in the quantum domain by means of the horizon wave-function (HWF) formalism applied to a spherically symmetric Gaussian state. When the charge-to-mass ratio q<1, the formalism allows for a straightforward quantum mechanical description of both inner and outer horizons. For q>1, where the classical theory predicts a naked singularity,...Go to contribution page
-
Sabine Hossenfelder (Nordita)21/07/2015, 16:00SeniorsI will discuss a new duality between strongly coupled and weakly coupled condensed matter systems. It can be obtained by combining the gauge-gravity duality with analog gravity. In my talk I will explain how one arrives at the new duality, what it can be good for, and what questions this finding raises.Go to contribution page
-
Orlando Panella (INFN)21/07/2015, 16:30We present the un-Casimir effect, namely the study of the Casimir energy in the presence of an unparticle component in addition to the electromagnetic field contribution. The distinctive feature of the un-Casimir effect is a fractalisation of metallic plates. This result emerges through a new dependence of the Casimir energy on the plate separation that scales with a continuous power...Go to contribution page
-
Prof. Eduardo Guendelman (Ben Gurion University)21/07/2015, 16:30SeniorsA new class of gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold are studied in some detail. These models involve an additional R2 (square of the scalar curvature) term as well as scalar matter field potentials of appropriate form so that the pertinent action is...Go to contribution page
-
Mariano Cadoni (University of cagliari)21/07/2015, 17:00SeniorsWe construct asymptotically flat black hole solutions of Einstein-scalar gravity sourced by a nontrivial scalar field with $1/r$ asymptotic behavior. Near the singularity the black hole behaves as the Janis-Newmann-Winicour-Wyman solution. The hairy black hole solutions allow for consistent thermodynamical description. At large mass they have the same thermodynamical behavior of the...Go to contribution page
-
Prof. Bernard Carr (QMU, London)22/07/2015, 09:00KeynotesBlack holes span 60 decades of mass - from the Planck scale ($10^{-5}$g) to the cosmological scale ($10^{22} M_\text{Sun}$) - and probe many domains of physics (quantum gravity, high-energy physics, gravitational physics, astrophysics and cosmology). Quantum black holes, here regarded as the ones for which quantum evaporation is important (i.e. those hotter than the CMB temperature), span the...Go to contribution page
-
Prof. George Ellis (Cape Town)22/07/2015, 10:00Black hole evaporation calculations are usually carried out in a static asymptotically flat context. However real black holes are imbedded in an expanding universe filled with Cosmic Background radiation. This talk will discuss the relevant horizons and causal limits in this context, and make the case that black hole evaporation cannot take place until very late stages in the expansion of the...Go to contribution page
-
Prof. Carlo Rovelli (Marseille University)22/07/2015, 11:30I describe an extension of the Schwarzschild metric that describes matter collapsing into a black hole and then bouncing out of a white hole. The metric is locally, but not globally, isomorphic to the Kruskal extension, and has a compact internal region where a violation of the Einstein equations mimics quantum effects. The metric may describe an actual black hole explosion.Go to contribution page
-
Prof. Daniel Grumiller (TU Vienna)22/07/2015, 14:00KeynotesIf the holographic principle is a true aspect of Nature it must work beyond AdS/CFT. In this talk I address a particular aspect of the question how general holography is by considering flat space holography. I report recent progress, in particular the calculation of stress tensor correlators in three-dimensional gravity, microstate counting and holographic entanglement entropy, all of which...Go to contribution page
-
22/07/2015, 15:00This is the *optional* excursion. We are going to the mountains with an about 15 minutes bus trip. Up there we visit an astronomical observatory. The fee is already included in the conference fee, and it is 10€ for each accompanying person. The registration for that event was included in the registration form at indico.Go to contribution page
-
Prof. Herman Verlinde (Princeton)23/07/2015, 09:30Keynotes
-
Prof. Steven Giddings (UC Santa Barbara)23/07/2015, 11:00KeynotesIf nature respects quantum-mechanical principles, this implies significant modification to our semiclassical picture of black holes. The ongoing project to image the black hole at the center of our galaxy offers a possible opportunity to probe such departures from this picture initiated by Schwarzschild.Go to contribution page
-
Robert Mann (University of Waterloo)23/07/2015, 12:00Black Hole Chemistry is a new perspective on black hole thermodynamics, one that indicates that once vacuum energy is taken into account, black holes behave more like chemical systems. As a consequence mass becomes chemical enthalpy, the notion of a thermodynamic volume appears, and black holes exhibit a broad range of chemical phenomena, including liquid/gas phase transitions similar to a...Go to contribution page
-
Prof. Claus Lämmerzahl (ZARM/Bremen)23/07/2015, 14:00Keynotes
-
Francesca Vidotto (Radboud University Nijmegen)23/07/2015, 15:00JuniorsQuantum gravity may allow black holes to tunnel into white holes. If so, the lifetime of a black hole would be shorter than the one given by Hawking evaporation, solving the information paradox. More interestingly, this could open to a new window for quantum-gravity phenomenology, in connection with the existence of primordial black holes. I discuss in particular the power of the associated...Go to contribution page
-
Dr Dennis D. Dietrich (Goethe-Universität)23/07/2015, 15:30SeniorsRecently, I have shown how an AdS$_{d+1}$ description of $d$ dimensional gauge field theories arises readily in the worldline formalism of quantum field theory. In this talk I will dicuss the role the AdS black hole plays in this worldline based approach to holography.Go to contribution page
-
Silke Britzen (MPIfR)23/07/2015, 15:30SeniorsHighest resolution Event Horizon Telescope (EHT) observations will probably soon tell us more about the supermassive black hole at the Galactic Centre (Sgr A*) and the cores of active galactic nuclei (AGN). It might also help to clarify the long-standing question whether the central massive objects in AGN are instead close pairs of black holes. Mergers of supermassive black hole pairs...Go to contribution page
-
Prof. REMO GARATTINI (University of Bergamo)23/07/2015, 16:00SeniorsWe consider the effects of Distorted Gravity on the traversability of the wormholes. In particular, we consider configurations which are sustained by their own gravitational quantum fluctuations. The Ultra-Violet divergences appearing to one loop are taken under control with the help of a Noncommutative geometry representation and Gravity's Rainbow. In this context, it will be shown that for...Go to contribution page
-
Dr Ilia Musco (CNRS, Observatorire de Paris, LUTH (Meudon))23/07/2015, 16:00SeniorsIn the context of gravitational collapse to form a black hole, one sees the appearance of inner and outer trapping horizons (foliated by marginally trapped surfaces), as was already noted in numerical calculations in the 1960s. This phenomenology has acquired new interest in connection with discussions of the Hayward unified first law of black hole dynamics. We have investigated the nature of...Go to contribution page
-
Prof. Mariafelicia De Laurentis (Tomsk State Pedagogical University)23/07/2015, 16:30SeniorsAxially symmetric solutions for f(R)-gravity can be derived starting from exact spherically symmetric solutions achieved by Noether symmetries. The method takes advantage of a complex coordinate transformation previously developed by Newman and Janis in general relativity. An example is worked out to show the general validity of the approach. The physical properties of the solution are also considered.Go to contribution page
-
Dr Fabio Scardigli (American University of the Middle East)23/07/2015, 16:30SeniorsWe compute the corrections to the Schwarzschild metric necessary to reproduce the Hawking temperature derived from a Generalized Uncertainty Principle (GUP), so that the GUP deformation parameter is directly linked to the deformation of the metric. Using this modified Schwarzschild metric, we compute corrections to the standard General Relativistic predictions for the light deflection and...Go to contribution page
-
Jürgen Struckmeier (GSI)23/07/2015, 17:00SeniorsAny physical theory that follows from an *action principle* should be *invariant in its form* under mappings of the reference frame in order to comply with the *general principle of relativity*. The required form-invariance of the action principle implies that the mapping must constitute a particular *extended canonical transformation*. In the realm of the covariant Hamiltonian formulation...Go to contribution page
-
Shoichi Kawamoto (Chung Yuan Christian University)23/07/2015, 17:00SeniorsWe study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the...Go to contribution page
-
Achim Kempf (PI/Waterloo)23/07/2015, 17:30
-
23/07/2015, 18:00
-
Gerardus 't Hooft (Utrecht University)23/07/2015, 19:30We rephrase the einstein-Hilbert theory of gravity by focusing on local conformal symmetry as an exact, but spontaneously broken symmetry of nature. We then put a constraint on the theory by imposing regularity of the action as the dilaton field variable tends to 0, which is a constraint on the small distance behaviour. This appears to turn a black hole into a regular, topologically trivial...Go to contribution page
-
Prof. Ralf Schützhold (Uni Duisburg-Essen)24/07/2015, 09:00Many quantum radiation phenomena such as black hole evaporation (Hawking effect) are far removed from experimental access. Therefore, analogies between these fundamental phenomena and laboratory physics can help to understand both sides better -- from a theoretical as well as from an experimental point of view. This talk will start with a brief introduction into black hole evaporation with...Go to contribution page
-
Prof. Achim Kempf (PI/Waterloo)24/07/2015, 10:00Keynotes
-
Elizabeth Winstanley (The University of Sheffield)24/07/2015, 11:30According to the no-hair conjecture, equilibrium black holes are simple objects, completely determined by global charges which can be measured at infinity. This is the case in Einstein-Maxwell theory due to beautiful uniqueness theorems. However, the no-hair conjecture is not true in general, and there is now a plethora of matter models possessing hairy black hole solutions. In this talk we...Go to contribution page
-
24/07/2015, 14:00KeynotesDiscussion: Steve Giddings / Carlo Rovelli Chair: Gerad 't HooftGo to contribution page
-
24/07/2015, 16:00
-
Mr ALI OVGUN (Eastern Mediterranean University-FAMAGUSTA , NORTHERN CYPRUS)StudentsPosterThe unbounded center-of-mass (CM) energy of colliding particles near horizon of a black hole emerges even in 1+1- dimensional Horava-Lifshitz gravity. The latter has imprints of renormalizable quantum gravity characteristics in accordance with simple power counting. The result obtained is valid also for a 1- dimensional Compton process between a massive/massless Hawking photon emaneting from...Go to contribution page
Choose timezone
Your profile timezone: