Stars on branes: the view from the brane

TL;DR

This paper investigates spherically symmetric stars on a brane within a five-dimensional bulk, highlighting differences from standard gravity and emphasizing the importance of global bulk conditions.

Contribution

It derives junction conditions for stars on a brane and analyzes static and collapse scenarios, revealing novel features compared to four-dimensional Einstein gravity.

Findings

Differences in star structure due to extra dimension

Static solutions exhibit unique junction conditions

Collapse behavior differs from standard gravity

Abstract

We consider spherically symmetric matter configurations on a four dimensional "brane" embedded in a five dimensional $Z_2$-symmetric "bulk". We write the junction conditions between the interior and exterior of these "stars", treat a couple of static examples in order to point out the differences with ordinary four dimensional Einstein gravity, consider briefly a collapse situation and conclude with the importance of a global view including asymptotic and regularity conditions in the bulk.