Effects of brane-flux transition on black holes in string theory

TL;DR

This paper explores how brane-flux transitions affect extremal black holes in string theory, showing that D3-branes can disappear and leave behind flux remnants that still encode black hole properties.

Contribution

It introduces a novel configuration with extra fluxes, analyzes brane disappearance via topological arguments, and proposes flux remnants as black hole carriers post-transition.

Findings

D3-branes can vanish through instantonic D5-branes.

Flux remnants can encode black hole degrees of freedom.

Topological arguments support the flux transition mechanism.

Abstract

Extremal N=2 black holes in four dimensions can be described by an ensemble of D3-branes wrapped on internal supersymmetric three-cycles of Calabi-Yau threefolds on which type IIB superstring theory is compactified. We construct a similar configuration, with extra RR and NS-NS three-form fluxes being turned on. We can avoid the Freed-Witten anomaly on the D3-branes by enforcing the pullback of these extra fluxes to the D3-branes to vanish at the classical level. In the setup the D3-brane charge is not conserved since it is classified as a trivial class in twisted K-theory. Consequently, the D3-branes may disappear by encountering an instantonic D5-brane localized in time. We discuss what happens on the black hole described by such disappearing D3-branes, relying mainly on topological arguments. Especially, we argue that another RR three-form flux will be left as a lump of remnant which is localized in the uncompactified four-dimensional space-time and that it may carry the same amount of degrees of freedom to describe a black hole, in cooperation with the original NS-NS flux, after this transition of the D3-branes.