17 research outputs found

    Regularity of squarefree monomial ideals

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    We survey a number of recent studies of the Castelnuovo-Mumford regularity of squarefree monomial ideals. Our focus is on bounds and exact values for the regularity in terms of combinatorial data from associated simplicial complexes and/or hypergraphs.Comment: 23 pages; survey paper; minor changes in V.

    Asymptotic Behavior of Ext functors for modules of finite complete intersection dimension

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    Let RR be a local ring, and let MM and NN be finitely generated RR-modules such that MM has finite complete intersection dimension. In this paper we define and study, under certain conditions, a pairing using the modules \Ext_R^i(M,N) which generalizes Buchweitz's notion of the Herbrand diference. We exploit this pairing to examine the number of consecutive vanishing of \Ext_R^i(M,N) needed to ensure that \Ext_R^i(M,N)=0 for all i0i\gg 0. Our results recover and improve on most of the known bounds in the literature, especially when RR has dimension at most two
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