The Combinatorial Nullstellensatz and DFT on Perfect Matchings in Bipartite Graphs

Timothy M. Brauch1, André E. Kézdy1, Hunter S. Snevily2
1Department of Mathematics University of Louisville Louisville, KY 40292 USA
2Department of Mathematics University of Idaho Moscow, ID 83844 USA

Abstract

The paper begins with a simple circular lock problem that shows how the Combinatorial Nullstellensatz relates to the discrete Fourier Transform.Specifically, the lock shows a relationship between detecting perfect matchings in bipartite graphs using the Combinatorial Nullstellensatz and detecting a maximum rank independent set in the intersection of two matroids in the Fourier transform of a specially chosen function. Finally, an application of the uncertainity principle computes a lower bound for the product of perfect matchings and the number of independent sets.