A New Approach to Superstring Field Theory

TL;DR

Berko\v{v}its proposes a new open superstring field theory action based on an N=4 topological ghost-free prescription that uses two BRST-like operators $G^+_0$ and $\tilde{G}^+_0$ to avoid contact-term divergences inherent in conventional picture-changing constructions. The open-string action $S_{open}$ with $g=e^V$ yields a gauge-invariant nonlinear theory whose massless sector reproduces $D=10$ SYM in four-dimensional superspace and, in appropriate limits, the self-dual open string reproduces self-dual YM. For closed strings, a corresponding kinetic action with two BRST-like operators is formulated, reproducing the known self-dual gravity action and the NS-NS sector of the closed RNS string; interactions are handled via covariantized gluing and a potential large-N interpretation links open-string and closed-string dynamics. The work highlights solutions to contact-term divergences and suggests intriguing connections to gauge-gravity dualities, while leaving RR contributions and full spacetime-supersymmetric formulations for future work.

Abstract

I review the construction of an action for open superstring field theory which does not suffer from the contact term problems of other approaches. I also discuss a possible generalization of this action for closed superstring field theory.