For an arbitrary positive integer T we introduce the notion of a (V, T)-module over a vertex algebra V, which is a generalization of a twisted V-module. Under some conditions on V, we construct an associative algebra A(m)(T)(V) for m is an element of (1/T)N and an A(m)(T)(V)-A(n)(T)(V)-bimodule A(n,m)(T)(V) for n,m is an element of (1/T)N and we establish a one-to-one correspondence between the set of isomorphism classes of simple left A(0)(T)(V)-modules and that of simple (1/T)N-graded (V, T)-modules.
展开▼
