Bounds on the Castelnuovo-Mumford regularity of tensor products
Bounds on the Castelnuovo-Mumford regularity of tensor products
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DOI:
10.1090/s0002-9939-07-08222-6
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发表时间:
2005-10
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影响因子:
--
通讯作者:
G. Caviglia
中科院分区:
文献类型:
--
作者:
G. Caviglia
In this paper we show how, given a complex of graded modules and knowing some partial Castelnuovo-Mumford regularities for all the modules in the complex and for all the positive homologies, it is possible to get a bound on the regularity of the zero homology. We use this to prove that if dim Tor R 1 (M, N) ≤ 1, then reg(M⊗N) < reg(M)+reg(N), generalizing results of Chandler, Conca and Herzog, and Sidman. Finally we give a description of the regularity of a module in terms of the postulation numbers of filter regular hyperplane restrictions.