Gromov-Witten theory of banded gerbes over schemes

Abstract

Let $X$ be a smooth complex projective algebraic variety. Let $\mathcal{G}$ be a $G$-banded gerbe with $G$ a finite abelian group. We prove an exact formula expressing genus $g$ orbifold Gromov-Witten invariants of $\mathcal{G}$ in terms of those of $X$.

v1:32 pages, preliminary version, comments welcome; v2: a typo removed, comments still welcome