Andreini, ElenaJiang, YunfengTseng, Hsian-Hua2012-01-232012-01-232011-01-31https://openscience.sissa.it/handle/1963/5262v1:32 pages, preliminary version, comments welcome; v2: a typo removed, comments still welcomeLet $X$ 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 $X$.enPreprintMAT/03 GEOMETRIA