Article ID Journal Published Year Pages File Type
4595770 Journal of Pure and Applied Algebra 2016 17 Pages PDF
Abstract

A natural extension of bipartite graphs are d  -partite clutters, where d≥2d≥2 is an integer. For a poset P, Ene, Herzog and Mohammadi introduced the d  -partite clutter CP,dCP,d of multichains of length d in P  , showing that it is Cohen–Macaulay. We prove that the cover ideal of CP,dCP,d admits an xixi-splitting, determining a recursive formula for its Betti numbers and generalizing a result of Francisco, Hà and Van Tuyl on the cover ideal of Cohen–Macaulay bipartite graphs. Moreover we prove a Betti splitting result for the Alexander dual of a Cohen–Macaulay simplicial complex. Interesting examples are given, in particular the first example of ideal that does not admit Betti splitting in any characteristic.

Related Topics
Physical Sciences and Engineering Mathematics Algebra and Number Theory
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