Toward Open-Closed String Theoretical Description of Rolling Tachyon

TL;DR

This paper explores a theoretical framework for describing the decay of unstable D-branes via open and closed string interactions, proposing a model that captures the transition to a stable tachyon vacuum while conserving energy.

Contribution

It introduces a toy model that demonstrates a time-dependent decay process of D-branes within open-closed string theory, advancing understanding of tachyon dynamics.

Findings

Constructed a toy model with time-dependent solutions

Showed the decay leads to a stable tachyon vacuum

Maintained energy conservation during decay process

Abstract

We consider how the time-dependent decay process of an unstable D-brane should be described in the full (quantum) open-closed string theory. It is argued that the system, starting from the unstable D-brane configuration, will evolve in time into the time-independent open string tachyon vacuum configuration which we assume to be finite, with the total energy conserved. As a concrete realization of this idea, we construct a toy model describing the open and closed string tachyons which admits such a time-dependent solution. The structure of our model has some resemblance to that of open-closed string field theory.