%0 Journal Article %T Monodromy at infinity of $A$-hypergeometric functions and toric compactifications %A Kiyoshi Takeuchi %J Mathematics %D 2008 %I arXiv %X We study $A$-hypergeometric functions introduced by Gelfand-Kapranov-Zelevinsky and prove a formula for the eigenvalues of their monodromy automorphisms defined by the analytic continuaions along large loops contained in complex lines parallel to the coordinate axes. A method of toric compactifications will be used to prove our main theorem. %U http://arxiv.org/abs/0812.0652v1