Twisted Tachyon Condensation in Closed String Field Theory

TL;DR

This paper investigates twisted tachyon instabilities in bosonic closed string theory on orbifolds, using string field theory to compute potentials and analyze decay processes into flat space or smaller deficit angle orbifolds.

Contribution

It provides the first explicit computation of tachyon potentials for C/Z_2 and C/Z_3 orbifolds within closed string field theory, supporting the decay conjecture.

Findings

Critical points at ~70% of expected deficit angle change

Both twisted and untwisted modes acquire vacuum expectation values

Potential computations support orbifold decay conjecture

Abstract

We consider twisted tachyons on C/Z_N orbifolds of bosonic closed string theory. It has been conjectured that these tachyonic instabilities correspond to decays of the orbifolds into flat space or into orbifolds with smaller deficit angles. We examine this conjecture using closed string field theory, with the string field truncated to low-level tachyons. We compute the tachyon potentials for C/Z_2 and C/Z_3 orbifolds and find critical points at depths that generate about 70% of the expected change in the deficit angle. We find that both twisted fields and untwisted modes localized near the apex of the cone acquire vacuum expectation values and contribute to the potential.