Closed String Tachyons and RG flows

TL;DR

This paper studies how bulk tachyon condensations in string theory's sigma models influence RG flows, showing that in certain regimes, tachyon condensation reduces the central charge, indicating a form of instability resolution.

Contribution

It demonstrates that tachyon condensation can decrease the central charge in a sigma model, providing insights into the dynamics of bulk tachyons and RG flows in string theory.

Findings

Tachyon condensation decreases the central charge in certain regimes.

Strong coupling backgrounds are encountered beyond the reliable RG analysis.

The analysis applies when the string coupling remains small during the flow.

Abstract

We consider bulk tachyon condensations in a non-linear sigma model whose low energy effective theory contains a nontrivial scalar potential. We argue that one would typically encounter a strong coupling background along a RG flow corresponding to a bulk tachyon condensation, beyond which the RG analysis would not be reliable. In a range of the flow in which the string coupling constant is small, we can show that the tachyon condensation actually decreases the central charge of the sigma model.