"Black Universe" epoch in String Cosmology

TL;DR

This paper explores a novel cosmological scenario where a black brane horizon forms in the Standard Model throat of string compactifications, linking black hole formation to phase transitions in dual gauge theories and implications for early universe evolution.

Contribution

It introduces the concept of a 'Black Universe' epoch where black brane horizons form in the Standard Model throat, connecting string cosmology with gauge theory phase transitions.

Findings

Critical energy density for black hole horizon formation calculated.

Duality between 'Black Universe' cosmology and hot gauge theory radiation established.

Addresses hierarchical multiple-throat scenarios and their cosmological implications.

Abstract

String theory compactification involves manifolds with multiple warp factors. For cosmological applications, one often introduces a short, high-energy inflationary throat, and a long,low-energy Standard Model throat. It is assumed that at the end of inflation,the excited Kaluza-Klein modes from the Inflationary throat tunnel to the SM throat and reheat Standard Model degrees of freedom, which are attached to probe brane(s). However, the huge hierarchy of energy scales can result in a highly dynamic transition of the throat geometry. We point out that in such a cosmological scenario the Standard Model throat (together with SM brane) will be cloaked by a Schwarzschild horizon, produced by the Kaluza-Klein modes tunneling from the short throat. The Black Brane formation is dual to the first order chiral phase transition of the cascading gauge theory. We calculate the critical energy density corresponding the formation of the the BH horizon in the long throat. We discuss the duality between "Black Universe" cosmology and an expanding universe driven by the hot gauge theory radiation. We address the new problem of the hierarchical multiple-throat scenarios: SM brane disappearance after the decay of the BH horizon.