How trapped surfaces jump in 2+1 dimensions

TL;DR

This paper presents an exact analysis of how trapped surfaces behave when matter falls into a black hole in a simplified 2+1 dimensional model, revealing non-local dynamics of marginally trapped tubes.

Contribution

It introduces a novel exact solution for trapped surface dynamics in a 2+1 dimensional black hole model, simplifying the complex 3+1 dimensional case.

Findings

Demonstrates outward movement of marginally trapped tubes upon matter infall

Provides an analytical description of non-local trapped surface behavior

Highlights differences from higher-dimensional black hole dynamics

Abstract

When a lump of matter falls into a black hole it is expected that a marginally trapped tube when hit moves outwards everywhere, even in regions not yet in causal contact with the infalling matter. But to describe this phenomenon analytically in 3+1 dimensions is difficult since gravitational radiation is emitted. By considering a particle falling into a toy model of a black hole in 2+1 dimensions an exact description of this non-local behaviour of a marginally trapped tube is found.