A family of simple non-weight modules over the twisted $N=2$ superconformal algebra

Abstract

We construct a class of non-weight modules over the twisted $N=2$ superconformal algebra $\T$. Let $\mathfrak{h}=\C L_0\oplus\C G_0$ be the Cartan subalgebra of $\T$, and let $\mathfrak{t}=\C L_0$ be the Cartan subalgebra of even part $\T_{\bar 0}$. These modules over $\T$ when restricted to the $\mathfrak{h}$ are free of rank $1$ or when restricted to the $\mathfrak{t}$ are free of rank $2$. We provide the sufficient and necessary conditions for those modules being simple, as well as giving the sufficient and necessary conditions for two $\T$-modules being isomorphic. We also compute the action of an automorphism on them. Moreover, based on the weighting functor introduced in \cite{N2}, a class of intermediate series modules $A_\sigma$ are obtained. As a byproduct, we give a sufficient condition for two $\T$-modules are not isomorphic.