7 research outputs found

    Coloring linear hypergraphs: the Erdos-Faber-Lovasz conjecture and the Combinatorial Nullstellensatz

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    The long-standing Erdos-Faber-Lovasz conjecture states that every n-uniform linear hypergaph with n edges has a proper vertex-coloring using n 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 Erdos-Faber-Lovasz 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

    Packing and covering in combinatorics

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