BRST Invariance of the Non-Perturbative Vacuum in Bosonic Open String Field Theory

TL;DR

This paper numerically verifies the BRST invariance of the non-perturbative vacuum in bosonic open string field theory, supporting its consistency and providing insights for analytic solutions.

Contribution

It demonstrates the numerical BRST invariance of the vacuum solution in Witten's string field theory, highlighting its zero-norm property and guiding future analytic work.

Findings

BRST invariance holds to good accuracy

Solution exhibits zero-norm property

Results support the consistency of the non-perturbative vacuum

Abstract

Tachyon condensation on a bosonic D-brane was recently demonstrated numerically in Witten's open string field theory with level truncation approximation. This non-perturbative vacuum, which is obtained by solving the equation of motion, has to satisfy furthermore the requirement of BRST invariance. This is indispensable in order for the theory around the non-perturbative vacuum to be consistent. We carry out the numerical analysis of the BRST invariance of the solution and find that it holds to a good accuracy. We also mention the zero-norm property of the solution. The observations in this paper are expected to give clues to the analytic expression of the vacuum solution.