Remarks on the rolling tachyon BCFT

TL;DR

This paper demonstrates how to compute boundary correlators for the rolling tachyon in Euclidean BCFT directly from Sen's boundary state, confirming known open string results and exploring implications for the timelike theory.

Contribution

It provides a direct method to calculate boundary correlators from Sen's boundary state and analyzes the open string spectrum in the context of the rolling tachyon.

Findings

Boundary correlators match perturbative open string results.

Explicit formulas for boundary correlators derived from boundary state.

Insights into the open string spectrum and timelike theory implications.

Abstract

It is shown how the boundary correlators of the Euclidean theory corresponding to the rolling tachyon solution can be calculated directly from Sen's boundary state. The resulting formulae reproduce precisely the expected perturbative open string answer. We also determine the open string spectrum and comment on the implications of our results for the timelike theory.