Closed String Tachyon Condensation on Twisted Circles

TL;DR

This paper investigates closed string tachyon condensation on twisted circles in string theory, demonstrating that the end state of condensation is supersymmetric type II theory and exploring related supergravity solutions.

Contribution

It constructs a conformal field theory interpolating between twisted circle models and flat space, revealing the endpoint of tachyon condensation as supersymmetric type II theory.

Findings

Tachyon condensation leads to supersymmetric type II theory.

A conformal field theory interpolates between models and flat space.

Tachyon dynamics are analyzed via supergravity fluctuations.

Abstract

We study IIA/B string theory compactified on twisted circles. These models possess closed string tachyons and reduce to type 0B/A theory in a special limit. Using methods of gauged linear sigma models and mirror symmetry we construct a conformal field theory which interpolates between these models and flat space via an auxiliary Liouville direction. Interpreting motion in the Liouville direction as renormalization group flow, we argue that the end point of tachyon condensation in all these models (including 0B/A theory) is supersymmetric type II theory. We also find a zero-slope limit of these models which is best described in a T-dual picture as a type II NS-NS fluxbrane. In this limit tachyon condensation is an interesting and well posed problem in supergravity. We explicitly determine the tachyon as a fluctuation of supergravity fields, and perform a rudimentary numerical analysis of the relevant flows.