Open String Field Theory around Universal Solutions

TL;DR

This paper investigates the spectrum of cubic open string field theory around universal solutions, revealing that open string excitations vanish after condensation, indicating a shift in the physical spectrum.

Contribution

It provides a detailed analysis of the cohomology and physical spectrum around universal solutions, highlighting the disappearance of open string excitations post-condensation.

Findings

Open string excitations disappear after condensation.

Cohomology of the new BRS charge differs from the original.

Universal solutions alter the physical spectrum.

Abstract

We study the physical spectrum of cubic open string field theory around universal solutions, which are constructed using the matter Virasoro operators and the ghost and anti-ghost fields. We find the cohomology of the new BRS charge around the solutions, which appear with a ghost number that differs from that of the original theory. Considering the gauge-unfixed string field theory, we conclude that open string excitations perturbatively disappear after the condensation of the string field to the solutions.