Asymptotically Nonrelativistic String Backgrounds

TL;DR

This paper investigates black brane solutions in nonrelativistic string theory backgrounds, revealing that certain solutions develop relativistic regions near horizons, while others maintain a nonrelativistic structure throughout.

Contribution

It demonstrates how black branes in nonrelativistic string backgrounds can have different geometric structures, with some developing relativistic throats and others preserving nonrelativistic geometry.

Findings

Black string backgrounds develop a relativistic throat near the horizon.

Transverse RR-charged black branes maintain a nonrelativistic structure everywhere.

Relativistic regions emerge only close to the black brane horizons.

Abstract

In recent years, interesting curved-space extensions of nonrelativistic (NR) string theory have been very actively pursued, where the background has a structure that is a stringy generalization of Newton-Cartan geometry. Here we show that the natural black branes of the NR theory, sourced by the familiar repertoire of stringy objects, generally have a different structure. The black string is our main example. We find that the source distorts the background significantly, generating a large throat within which physics is in fact relativistic. It is only far away from the throat that the background approaches the string Newton-Cartan form. We show that exactly the same is true for the longitudinal RR-charged black brane. On the other hand, the transverse RR-charged black brane turns out to have a proper string Newton-Cartan structure everywhere, not just asymptotically.