The Berkovits-Vafa Construction and Nonlinear Realizations

TL;DR

This paper discusses the extension of the Berkovits-Vafa construction, showing how critical and noncritical string theories relate through nonlinear realizations of the super-Virasoro algebra, connecting to established nonlinear realization techniques.

Contribution

It demonstrates that the nonlinear realization of the super-Virasoro algebra in string theory can be understood using standard nonlinear realization methods, extending previous work to noncritical cases.

Findings

Extended the embedding of Virasoro into super-Virasoro algebra to noncritical strings.

Interpreted the nonlinear realization using established nonlinear realization techniques.

Connected earlier work of Kunitomo to the current framework.

Abstract

Berkovits and Vafa recently showed that critical string theories can be considered as critical superstring theories with a special choice of background. The embedding of the Virasoro algebra into the super-Virasoro algebra involved in this construction has been extended to the noncritical case by Berkovits and Ohta. It is shown that the resulting nonlinear realization of the super-Virasoro algebra can be interpreted using standard techniques from the theory of nonlinear realizations. This extends earlier work of Kunitomo.