On the better behaved version of the GKZ hypergeometric system
arXiv:1011.5720
Abstract
We consider a version of the generalized hypergeometric system introduced by Gelfand, Kapranov and Zelevinski (GKZ) suited for the case when the underlying lattice is replaced by a finitely generated abelian group. In contrast to the usual GKZ hypergeometric system, the rank of the better behaved GKZ hypergeometric system is always the expected one. We give largely self-contained proofs of many properties of this system. The discussion is intimately related to the study of the variations of Hodge structures of hypersurfaces in algebraic tori.
LaTex, 22 pages; v2 is a major revision: the introduction, sections 4 and 5 have been changed; section 5 is new; v3 published version