Non-weight modules over the BMS-Kac-Moody algebra

In this paper, we construct and classify a class of non-weight modules over the BMS-Kac-Moody algebra, which are free modules of rank one when restricted to the universal enveloping algebra of the Cartan subalgebra (modulo center). We give the classification of such modules. Moreover, the irreducibility and the isomorphism classes of these modules are determined.