Exact self-gravitating N-body motion in the CGHS model

TL;DR

This paper provides exact solutions for self-gravitating N-body systems in a two-dimensional dilaton gravity model, showing black hole formation from infalling particles and analyzing their singularities and horizons.

Contribution

It introduces an exactly solvable N-body particle action in 2D dilaton gravity, enabling nonperturbative analysis of black hole formation from multiple particles.

Findings

Exact solutions for N-body self-gravitating systems in 2D dilaton gravity.

Single particles can form black holes due to the absence of a critical mass.

Additional time-like singularities are generated by infalling particles.

Abstract

In the asymptotically flat two-dimensional dilaton gravity, we present an N-body particle action which has a dilaton coupled mass term for the exact solubility. This gives nonperturbative exact solutions for the N-body self-gravitating system, so the infalling particles form a black hole and their trajectories are exactly described. In our two-dimensional case, the critical mass for the formation of black holes does not exist, so even a single particle forms a black hole, which means that we can treat many black holes. The infalling particles give additional time-like singularities in addition to the space-like black hole singularity. However, the latter singularities can be properly cloaked by the future horizons within some conditions.