XV Black Holes Workshop

Session

Session 8 A

20 Dec 2022, 16:30

ISCTE - University Institute of Lisbon

150. M. Reintjes: On the regularity implied by the assumptions of geometry

20/12/2022, 16:30

The Regularity Transformation (RT-)equations are an elliptic system of partial differential equations which determines coordinate and gauge transformations that remove apparent singularities in space- time by furnishing optimal metric regularity. The resulting gain of one derivative for connections above their Lp curvature suffices to establish Uhlenbeck compactness. By developing an existence...

155. M. de Cesare: Evolving black hole with scalar field accretion

20/12/2022, 16:45

I will present a new method to study evolving black holes in general relativity. Approximate analytical solutions are obtained by expanding the Einstein field equations close to the trapping horizon for a dynamical spherically symmetric black hole in the presence of a minimally coupled self-interacting scalar field. This is made possible by a new parametrization of the metric, in which the...

152. E. Costa Filho: Abelian-Higgs balls and stars: a UV completion for Proca self-interactions

20/12/2022, 17:00

We consider an Abelian-Higgs type model wherein a complex vector field gains mass via spontaneous symmetry breaking. This model can be considered as a UV completion of a complex Proca model with self-interactions. We study the flat spacetime (“balls”) and self-gravitating (“stars”) solitons describing some of their mathematical and physical properties. The stars reduce to the well-known...

153. A. Bokulic: Can nonlinear electromagnetic fields regularize black hole singularities?

20/12/2022, 17:15

Before considering any modifications of classical gravitational theory, the question is whether black hole singularities can be cured by coupling to some type of matter fields. We inspect nonlinear electromagnetic theories as candidates for resolving black hole singularities. This problem was first systematically addressed by Bronnikov, whose no-go theorems are focused on spherically symmetric...

154. P. Kotlarik: Gravity of static thin discs around black holes

20/12/2022, 17:30

The astrophysical black holes are not isolated bodies. One of the most prominent structures which form in the proximity of the black hole is a thin accretion disc. Whether treated in Newton’s theory or in general relativity, in the static and axially symmetric case the gravitational potential is determined by the Laplace equation. Though clear in principle, its solution is only known...

151. C. Peterson Bórquez: Numerical evolution of Good-Bad-Ugly-F system as a toy model for hyperboloidal numerical relativity

20/12/2022, 17:45

The numerical solution of a system of hyperbolic PDEs all the way to future null infinity requires the knowledge of asymptotics. The Good-Bad-Ugly-F model is known to mimic the asymptotic properties of Einstein equations in generalized harmonic gauge. In this talk I will present the results of numerical evolution of this system, both in spherical symmetry and full 3D, with the scope of using...