Lightsheets, Branes and the Covariant Entropy Bound

TL;DR

This paper explores the geometry of lightsheets near branes, showing how null geodesics behave and discussing implications for the covariant entropy bound in brane world scenarios.

Contribution

It provides a detailed analysis of lightsheet geometry near branes and examines how this affects the covariant entropy bound in brane world models.

Findings

Null geodesics near branes are gravitationally bound, staying within distance d.

Lightsheet geometry near branes resembles that of the brane when coarse-grained over distance d.

Implications for the covariant entropy bound in brane scenarios are discussed.

Abstract

We investigate the geometry of lightsheets comprised of null geodesics near a brane. Null geodesics which begin parallel to a brane a distance d away are typically gravitationally bound to the brane, so that the maximum distance from the geodesic to the brane never exceeds d. The geometry of resulting lightsheets is similar to that of the brane if one coarse grains over distances of order d. We discuss the implications for the covariant entropy bound applied to brane worlds.