Whittaker pairs for the Virasoro algebra and the Gaiotto - BMT states
  In this paper we analyze Whittaker modules for two families of Wittaker pairs related to the subalgebras of the Virasoro algebra generated by L_r,..., L_{2r} and L_1,L_n. The structure theorems for the corresponding universal Whittaker modules are proved and some of their consequences are derived. All the Gaiotto {arXiv:0908.0307} and the Bonelli-Maruyoshi-Tanzini {arXiv:1112.1691} states in an arbitrary Virasoro algebra Verma module are explicitly constructed. 
Ewa Felinska, Zbigniew Jaskolski and Michal Kosztolowicz
math-ph hep-th math.MP