Level Truncated Tachyon Potential in Various Gauges

TL;DR

This paper investigates the behavior of the tachyon potential in cubic open string field theory using a new gauge fixing condition, revealing that physical solutions are gauge-invariant and the potential is smooth in certain gauges.

Contribution

The authors introduce a novel gauge fixing condition and analyze its effects on tachyon condensation, demonstrating the persistence of a physical extremum and the gauge-artifact nature of other solutions.

Findings

Only one real non-trivial extremum exists in the well-defined gauge parameter region.

Other solutions are identified as gauge artifacts.

Tachyon potential is smooth around Landau-type gauge.

Abstract

New gauge fixing condition with single gauge parameter proposed by the authors is applied to the level truncated analysis of tachyon condensation in cubic open string field theory. It is found that the only one real non-trivial extremum persists to appear in the well-defined region of the gauge parameter, while the other solutions are turned out to be gauge-artifacts. Contrary to the previously known pathology in the Feynman-Siegel gauge, tachyon potential is remarkably smooth enough around Landau-type gauge.