Properties of Asymptotically Flat Two-Dimensional Black Holes

TL;DR

This paper explores the properties, formation, and quantum aspects of two-dimensional asymptotically flat black holes, highlighting their thermodynamics, particle dynamics, and differences from higher-dimensional cases.

Contribution

It introduces matter sources leading to such black holes as collapse endpoints and analyzes their quantum and thermodynamic properties, revealing source-dependent cutoff behaviors.

Findings

Test particles fall through horizons in finite proper time

Black holes exhibit a fundamental length scale in thermodynamics

Eigenmode cutoff depends on sources, unlike in 4D

Abstract

We investigate properties of two-dimensional asymptotically flat black holes which arise in both string theory and in scale invariant theories of gravity. By introducing matter sources in the field equations we show how such objects can arise as the endpoint of gravitational collapse. We examine the motion of test particles outside the horizons, and show that they fall through in a finite amount of proper time and an infinite amount of coordinate time. We also investigate the thermodynamic and quantum properties, which give rise to a fundamental length scale. The 't Hooft prescription for cutting off eigenmodes of particle wave functions is shown to be source dependent, unlike the four-dimensional case. The relationship between these black holes and those considered previously in $(1+1)$ dimensions is discussed.