Constraints on cosmologies inside black holes

TL;DR

This paper investigates the constraints on constructing holographic models with closed FRW cosmologies within black holes, revealing tension limitations and the effects of interface branes in higher dimensions.

Contribution

It demonstrates that in higher dimensions, smooth Euclidean solutions restrict brane tension, and adding interface branes does not relax these constraints.

Findings

Smooth Euclidean solutions limit brane tension to T<T_* in dimensions d>2

Adding interface branes does not relax tension constraints

Constraints prevent realizing scale separation between brane and bulk

Abstract

We study the construction of holographic models with closed FRW cosmologies on the worldvolume of a constant-tension brane inside a Schwarzschild-AdS black hole. In dimensions d>2, having a smooth Euclidean solution where the brane does not self-intersect limits the brane tension to T<T_*, preventing us from realising a separation of scales between the brane and bulk curvature scales. We show that adding interface branes to this model does not relax the condition on the brane tension.