Unitary modules for the twisted Heisenberg-Virasoro algebra
  In this paper, the conjugate-linear anti-involutions and the unitary irreducible modules of the intermediate series over the twisted Heisenberg-Virasoro algebra are classified respectively. We prove that any unitary irreducible module of the intermediate series over the twisted Heisenberg-Virasoro algebra is of the form $\mathcal{A}_{a,b,c}$ for $a\in \mathbb{R}, b\in 1/2+\sqrt{-1}\mathbb{R}, c\in \mathbb{C}.$ 
Xiufu Zhang, Shaobin Tan
math.RA