Coloring linear hypergraphs: the Erdős-Faber-Lovász conjecture and the Combinatorial Nullstellensatz
arXiv:2007.00685 · doi:10.1007/s10623-021-00859-7
Abstract
The long-standing Erdős-Faber-Lovász conjecture states that every -uniform linear hypergaph with edges has a proper vertex-coloring using colors. In this paper we propose an algebraic framework to the problem and formulate a corresponding stronger conjecture. Using the Combinatorial Nullstellensatz, we reduce the Erdős-Faber-Lovász conjecture to the existence of non-zero coefficients in certain polynomials. These coefficients are in turn related to the number of orientations with prescribed in-degree sequences of some auxiliary graphs. We prove the existence of certain orientations, which verifies a necessary condition for our algebraic approach to work.