XV Black Holes Workshop

Session

Session 3 B

19 Dec 2022, 14:30

Auditório B2.03 (ISCTE-IUL)

107. N. Santos: A little hair can make a big difference: local thermodynamic stability of hairy black holes

19/12/2022, 14:30

The local thermodynamic stability of a black hole (BH) in the canonical ensemble is defined by the positivity of the specific heat at constant global charges. Schwarzschild BHs in thermal equilibrium with the environment are always unstable against small fluctuations of energy, whereas Reissner-Nordström/Kerr BHs with sufficiently large specific electric charge/angular momentum are stable. One...

108. T. Fernandes: The canonical ensemble of a d-dimensional Reissner-Nordström black hole in a cavity

19/12/2022, 14:45

We construct the canonical ensemble of a Reissner-Nordström black hole in a cavity for an arbitrary number of dimensions. The system of a charged black hole in a cavity can be described by a partition function given by the Euclidean path integral approach, where we consider the usual Einstein-Maxwell action with the Gibbons-Hawking-York boundary term and an additional boundary term depending...

109. S. Nampuri: Wormholes from automorphic forms in string theory: A black hole counting story

19/12/2022, 15:00

We use the exact statistical degeneracy formula of single-centred 1/4 BPS dyonic black holes in 4D N = 4 toroidally compactified heterotic string theory, given in terms of the Igusa cusp form of Sp(2,Z) to write down the gravitational path integral that captures black hole degeneracy as a sum over Euclidean backgrounds including orbifolds of the Euclidean AdS2 × S2 attractor geometry. We...

110. K. Uzawa: Dynamical branes on expanding orbifold and complex projective space

19/12/2022, 15:15

We construct some new dynamical p-brane solutions to gravity theories on curved backgrounds. These solutions depend on time and are carriers of the p-form field strength. The simplest such solutions have the function of (p + 1)-dimensional worldvolume spacetime, i.e. dynamical p-branes. We discuss the relations between dynamical branes, a new time-dependent solution on complex projective space...

111. A. García-Quismondo: Polymeric quantisation of the interior of a Schwarzschild black hole

19/12/2022, 15:30

In this talk, I will present some recent results concerning the loop quantisation of the interior region of a Schwarzschild black hole within the framework of loop quantum cosmology and a preliminary study of the physical states of the quantum theory. We start from a classical canonical description based on an extension of the phase space of Kantowski-Sachs cosmologies. Following the programme...

112. A. Sanna: Effective models of nonsingular quantum black holes

19/12/2022, 15:45

Penrose’s singularity theorem proved the utter inevitability of spacetime singularity formation in general relativity during gravitational collapse, where the theory completely loses its predictive powers. It is generally believed that this problem will find a solution in a theory of quantum gravity (QG), whose effects have so far been assumed to act at the Planck length. Instead, this talk...