Backreaction in Closed String Tachyon Condensation

TL;DR

This paper investigates how massless string production affects the background in closed string tachyon condensation, revealing significant backreaction in large dimensions through conformal perturbation theory.

Contribution

It provides a detailed analysis of backreaction effects in closed string tachyon condensation using conformal perturbation theory, extending understanding of string dynamics in this context.

Findings

Backreaction can be significant in large (supercritical) dimensions.

Derived modified equations of motion for massless strings.

Estimated the impact on the background dilaton.

Abstract

We consider backreaction due to production of massless strings in the background of a condensing closed string tachyon. Working in the region of weak tachyon, we find the modified equations of motion for massless strings with conformal perturbation theory. We solve for the positive and negative frequency modes and estimate the backreaction on the background dilaton. In large (supercritical) dimensions, we find that the backreaction can be significant in a large region of spacetime. We work with the bosonic string, but we expect these results to carry over into the heterotic case.