Alpha-prime corrections to space-like branes

TL;DR

This paper investigates higher order string corrections to space-like branes, revealing that perturbative effects prevent reaching the singularity, similar to stretched horizons in black holes, thus challenging classical singularity descriptions.

Contribution

It provides the first perturbative analysis of $oldsymbol{ ext{α'}}$ corrections to heterotic S-brane backgrounds, showing these corrections prevent access to the singularity within supergravity.

Findings

Perturbative $oldsymbol{ ext{α'}}$ corrections do not allow reaching the singularity.

Supergravity framework breaks down near $oldsymbol{t o ext{small}}$ scales.

Results suggest a stretched horizon analogy for space-like singularities.

Abstract

Space-like branes or S-branes are certain class of time dependent solutions of M/string theories having isometries ISO(p+1) $\times$ SO(d-p-2,1), where $d=11,10$ respectively and have singularities at t=0. In \cite{Roy:2006du}, we found that the asymptotically flat S-branes have the structure of generalized Kasner geometry near t=0. In this work we evaluate higher order $\alpha'$ corrections perturbatively to the heterotic string Kasner backgrounds to probe the singularity at t=0. We generally find that the perturbative corrections do not permit us to reach the singular point, as the supergravity framework fails near $t \sim {\sqrt \alpha'}$ blurring the origin of space-like singularities. This is analogous to the concept of stretched horizons in the case of black holes.