Taming the Tachyon in Cubic String Field Theory

TL;DR

This paper investigates the behavior of the rolling tachyon in cubic open string field theory, showing it has oscillatory solutions that can be transformed into exponential solutions via a field redefinition, linking CSFT and BSFT.

Contribution

It demonstrates a field redefinition that maps oscillatory solutions in CSFT to exponential solutions in BSFT, clarifying tachyon dynamics.

Findings

CSFT tachyon solutions are oscillatory and well-defined.

A field redefinition relates CSFT solutions to BSFT solutions.

Oscillatory CSFT solutions correspond to exponential BSFT solutions.

Abstract

We give evidence based on level-truncation computations that the rolling tachyon in cubic open string field theory (CSFT) has a well-defined but wildly oscillatory time-dependent solution which goes as $e^t$ for $t \to -\infty$. We show that a field redefinition taking the CSFT effective tachyon action to the analogous boundary string field theory (BSFT) action takes the oscillatory CSFT solution to the pure exponential solution $e^t$ of the BSFT action.