The Regularity of Binomial Edge Ideals of Graphs

نویسندگان

  • DARIUSH KIANI
  • SARA SAEEDI MADANI
چکیده

We prove two recent conjectures on some upper bounds for the Castelnuovo-Mumford regularity of the binomial edge ideals of some different classes of graphs. We prove the conjecture of Matsuda and Murai for chordal graphs. We also prove the conjecture due to the authors for a class of chordal graphs. We determine the regularity of the binomial edge ideal of the join of graphs in terms of the regularity of the original graphs, and consequently prove the conjecture of Matsuda and Murai for such a graph, and hence for complete t-partite graphs. We also generalize some results of Schenzel and Zafar about complete t-partite graphs. Moreover, we give some more general criterion to construct graphs for which those conjectures are true. As a consequence, we prove the conjecture of Matsuda and Murai for any graph which is obtained by adding whiskers to each vertex of another graph.

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تاریخ انتشار 2013