$(G,χ_φ)$-equivariant $φ$-coordinated quasi modules for nonlocal vertex algebras

Abstract: In this paper, we study $(G,\chi_{\phi})$-equivariant $\phi$-coordinated quasi modules for nonlocal vertex algebras. Among the main results, we establish several conceptual results, including a generalized commutator formula and a general construction of weak quantum vertex algebras and their $(G,\chi_{\phi})$-equivariant $\phi$-coordinated quasi modules. As an application, we also construct (equivariant) $\phi$-coordinated quasi modules for lattice vertex algebras by using Lepowsky's work on twisted vertex operators.