Tensor product weight modules over the Virasoro algebra (Q2869832)

An interesting class of simple modules over the Virasoro algebra was constructed in [\textit{H. Zhang}, J. Algebra 190, No. 1, 1--10 (1997; Zbl 0884.17017)] by considering tensor products of certain simple highest weight modules with some simple modules from the intermediate series.NEWLINENEWLINEThe paper under review provides a sufficient and necessary condition for the tensor products of a simple highest weight Virasoro module and a simple Virasoro module from the intermediate series to be a simple Virasoro module. Furthermore, the authors classify all simple Virasoro modules which can be obtained in this way up to isomorphism.