Homotopy Batalin–Vilkovisky algebras

Abstract

This paper provides an explicit cobrant resolution of the operad encoding Batalin{Vilkovisky algebras. Thus it denes the notion of homotopy Batalin{Vilkovisky algebras with the required homotopy properties. To dene this resolution, we extend the theory of Koszul duality to operads and properads that are dened by quadratic and linear relations. The operad encoding Batalin{Vilkovisky algebras is shown to be Koszul in this sense. This allows us to prove a Poincar e{Birkho{Witt Theorem for such an operad and to give an explicit small quasi-free resolution for it. This particular resolution enables us to describe the deformation theory and homotopy theory of BV-algebras and of homotopy BV-algebras. We show that any topological conformal eld theory carries a homotopy BV- algebra structure which lifts the BV-algebra structure on homology. The same result is proved for the singular chain complex of the double loop space of a topological space endowed with an action of the circle. We also prove the cyclic Deligne conjecture with this cobrant resolution of the operad BV . We develop the general obstruction theory for algebras over the Koszul resolution of a properad and apply it to extend a conjecture of Lian{Zuckerman, showing that certain vertex algebras have an explicit homotopy BV-algebra structure.