Combinatorics behind discriminants of polynomial systems

Abstract: In the 1970s, Kouchnirenko, Bernstein, and Khovanskii noticed that the geometry of a generic system of polynomial equations is determined by the geometry of its Newton polytopes. In the 1990s, Gelfand, Kapranov, Zelevinsky, and Sturmfels extended this observation to discriminants and resultants of generic polynomials. Particularly, well-known open questions about the irreducibility of discriminants and sets of solutions of such systems lead to questions about the corresponding geometric property of tuples of polytopes: Minkowski linear independence. To address these questions, we encode Minkowski linear independence into a finite matroid and characterize its bases, circuits, and cyclics. The obtained combinatorial results are used in the subsequent work to describe components of discriminants for generic square polynomial systems.