Multigraded Hurwitz forms

Abstract

The Hurwitz form of a projective variety characterizes linear spaces of complementary dimension which meet the variety non-transversally. We extend this notion to varieties in a product of projective spaces. This parallels the multigraded Chow forms due to Osserman and Trager. We study the degrees of multigraded Hurwitz forms. An explicit degree formula is given for complete intersections. This offers a new tool for elimination theory that has many applications, ranging from Nash equilibria to Feynman integrals.