New theoretical approaches to black holes

TL;DR

This paper explores new local horizon concepts in black hole physics and develops a viscous fluid analogy to describe their dynamics, offering a novel perspective beyond traditional event horizon models.

Contribution

It introduces a new mathematical framework for black hole horizons based on local trapped surface foliations and extends the membrane paradigm with a modified viscous fluid analogy.

Findings

New local horizon concepts based on trapped surfaces

Development of a viscous fluid analogy with sign change in bulk viscosity

Potential implications for black hole dynamics modeling

Abstract

Quite recently, some new mathematical approaches to black holes have appeared in the literature. They do not rely on the classical concept of event horizon -- which is very global, but on the local concept of hypersurfaces foliated by trapped surfaces. After a brief introduction to these new horizons, we focus on a viscous fluid analogy that can be developed to describe their dynamics, in a fashion similar to the membrane paradigm introduced for event horizons in the seventies, but with a significant change of sign of the bulk viscosity.