Moduli Vacuum Bubbles Produced by Evaporating Black Holes

TL;DR

This paper explores how evaporating black holes can produce moduli vacuum bubbles due to temperature-dependent effective potentials, potentially trapping particles, altering emission spectra, and leaving behind dark matter remnants.

Contribution

It introduces a model of temperature-dependent vacuum bubbles around black holes, combining Casimir effects and extra dimensions, with implications for black hole physics and dark matter.

Findings

Black hole bubbles can be highly opaque to low energy particles.

High temperature black holes may form symmetry-breaking false vacuum bubbles.

Vacuum bubbles could contribute to dark matter after black hole evaporation.

Abstract

We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.