A Cyclic Operad in the Category of Artin Stacks and Gravitational Correlators
Abstract
Description
We define an Artin stack which may be considered as a substitute for the non-existing (or empty) moduli space of stable two-pointed curves of genus zero. We show that this Artin stack can be viewed as the first term of a cyclic operad in the category of stacks. Applying the homology functor we obtain a linear cyclic operad. We formulate conjectures which assert that cohomology of a smooth projective variety has the structure of an algebra over this homology operad and that gravitational quantum cohomology can naturally expressed in terms of this algebra. As a test for these conjectures we show how certain well-known relations between gravitational correlators can be deduced from them.
Reference added for the formula in Prop. 11.6. Prop 11.7 corrected. Introduction changed accordingly
Reference added for the formula in Prop. 11.6. Prop 11.7 corrected. Introduction changed accordingly