Gravitational Radiation of Rolling Tachyon

TL;DR

This paper calculates the emission of massless closed string states caused by a rolling open string tachyon and examines how back reaction influences the tachyon's evolution, revealing different behaviors based on string coupling strength.

Contribution

It provides a detailed computation of gravitational radiation from a rolling tachyon and analyzes back reaction effects, extending understanding of tachyon dynamics in string theory.

Findings

Tachyonic matter persists at late times for small string coupling.

High string coupling leads to rapid evaporation of the tachyonic matter.

Implications for boundary conformal field theory g-theorem are discussed.

Abstract

In this paper we compute the radiation of the massless closed string states due to the non-vanishing coupling to the rolling open string tachyon with co-dimensions larger than 2, and discuss the effect of back reaction to the motion of the rolling tachyon. We find that for small string coupling, the tachyonic matter remains in the late time, but it will completely evaporate away over a short time of few string scales if the string coupling is huge. Comment on the implication of our results to the g-theorem of boundary conformal field theory is given.