A Course in Vertex Algebra
This book offers an introduction to vertex algebra based on a new approach. The new approach says that a vertex algebra is an associative algebra such that the underlying Lie algebra is a vertex Lie algebra. In particular, vertex algebras can be formulated in terms of a single multiplication and they behave like associative algebras with respect to it. Chapter 1 is the introduction. In chapter 2 we discuss many examples of vertex Lie algebras and we show that vertex Lie algebras form a full subcategory of the category of "local" Lie algebras. In chapter 3 we introduce associative, commutative, and Poisson vertex algebras and vertex algebra modules and we show that graded associative vertex algebras form a full subcategory of the category of "local" associative algebras. In chapter 4 we give a systematic presentation of the vertex algebra identities, proving in particular the equivalence of various axiom systems, and we use filtrations to prove results about generating subspaces with the PBW-property, with and without repeats. In chapter 5 we explain three constructions of the enveloping vertex algebra of a vertex Lie algebra and prove the PBW-theorem. In chapter 6 we prove the Zhu correspondence between N-graded vertex algebra modules and modules over the Zhu algebra.