XV Black Holes Workshop

Session

Session 1

Dec 19, 2022, 9:15 AM

ISCTE - University Institute of Lisbon

89. J. Lemos: Thermodynamics of Schwarzschild-de Sitter and Nariai spaces in the 50 years of Bekenstein’s black hole entropy

12/19/22, 9:15 AM

In 1972 Bekenstein put forward the idea that a black has an entropy S proportional to its area A in Planck units. Bekenstein’s black hole entropy was published in Nuovo Cimento. Hawking, developing quantum field theory calculations in curved spacetime, soon showed that the constant of proportionality in the entropy formula is one quarter, so that S = A/4, and that indeed a black hole has...

90. P. Luz: The effects of intrinsic spin of matter in relativistic cosmology and black holes formation

12/19/22, 9:30 AM

Using the covariant 1+3 threading spacetime decomposition, we discuss solutions of the Einstein-Cartan theory sourced by a cosmological perfect fluid composed by particles with intrinsic spin. It is shown that, even in the presence of intrinsic spin of matter, the metric tensor is described by a general FLRW solution, however the Weyl tensor might not vanish. The coupling between the intrinsic...

91. P. Fernandes: A new approach and code for spinning black holes in modified gravity

12/19/22, 9:45 AM

We discuss and implement a spectral method approach to computing stationary and axisymmetric black hole solutions and their properties in modified theories of gravity. The resulting code is written in the Julia language and is transparent and easily adapted to new settings. We test the code on both general relativity and on Einstein-Scalar-Gauss-Bonnet gravity. It is accurate and fast,...

92. H. Rüter: Hyperbolic-like encounters of binary black holes with the numerical relativity code SpEC

12/19/22, 10:00 AM

We present results on the encounter of two black holes that are initially on a hyperbolic-like orbit simulated with the numerical relativity code SpEC. We discuss the dynamical capture scenario as well as the scattering scenario, in which the black holes remain unbound during the encounter. In dynamical captures the binary becomes bound due to the emission of gravitational waves, which poses a...

93. J. G. Rosa: Determining the spin of light primordial black holes with Hawking radiation

12/19/22, 10:15 AM

We propose a method to determine the mass and spin of primordial black holes (PBHs) in the mass range 5 × 10^7 − 10^12 kg (Hawking temperatures ∼ 10 MeV – 200 GeV), based on measuring the energy of specific features in the photon Hawking emission spectrum, including both primary and secondary components. This is motivated by scenarios where PBHs in this mass range spin up as they evaporate,...