Yang-Baxter deformations of the OSP(1|2) WZW model

TL;DR

This paper classifies classical r-matrices for the osp(1|2) superalgebra, constructs corresponding Yang-Baxter deformations of the WZW model, and analyzes their geometric and supergravity properties, revealing non-unimodular, non-Abelian structures.

Contribution

It provides a comprehensive classification of classical r-matrices for osp(1|2) and explores their impact on Yang-Baxter deformations of the WZW model, including supergravity solution analysis.

Findings

All classical r-matrices are non-Abelian and non-unimodular.

Deformed models do not satisfy graded generalized supergravity equations.

Undeformed background solves supergravity equations with a supervector field.

Abstract

We obtain inequivalent classical r-matrices of the $osp(1|2)$ Lie superalgebra as real solutions of the graded (modified) classical Yang-Baxter equation, in such a way that the corresponding automorphism transformation is employed. Then, Yang-Baxter deformations of the Wess-Zumino-Witten model based on the OSP$(1|2)$ Lie supergroup are specified by super skew-symmetric classical r-matrices. In this regard, the effect coming from the deformation is reflected as the coefficient of both metric and $B$-field. Furthermore, it is shown that all resulting classical r-matrices are non-Abelian and also non-unimodular, which leads us to graded generalized supergravity equations. We show that the background of undeformed model is a solution of the graded generalized supergravity equations when supplemented by an appropriate supervector field obtaining from the linear combination of the Killing supervectors corresponding to the background, while the deformed models do not satisfy these equations. This is consistent with our expectations, since the deformed models under consideration do not describe a Green-Schwarz superstring. However, the deformed backgrounds are interesting, in particular in the OSP$(1|2)$ case they are rare, much hard technical work was needed to obtain them.