String Memories ... Lost and Regained

TL;DR

This paper investigates string theory corrections to gravitational waves from black hole mergers, suggesting potential observable effects and the possibility of recovering lost stringy memory through ring-down analysis.

Contribution

It models black hole mergers with string theory objects and explores how string corrections influence gravitational wave signals and memory effects.

Findings

String corrections may leave detectable footprints in gravitational waves.

Loop effects can destabilize string resonances, obscuring memory signals.

Ring-down phase analysis might recover lost stringy memory effects.

Abstract

We discuss stringy ${\alpha'}$ corrections to the gravitational wave signal generated in the merging of two black holes. We model the merging with two BPS compact massive objects in the heterotic string, described by standard vertex operators or coherent states. Despite the expected cubic suppression in ${\alpha'}$ w.r.t. the General Relativity result, at tree level the string corrections seem to leave a footprint or a memory on the gravitational wave signals within the sensitivity region of aLIGO/VIRGO and future interferometers. Including loop effects that broaden and destabilise the string resonances suggests a sort of lost stringy memory effect that can be regained through the analysis of the quasi normal modes in the ring-down phase.