Lyubeznik Numbers of Monomial Ideals
نویسندگان
چکیده
Let R = k[x1, ..., xn] be the polynomial ring in n independent variables, where k is a field. In this work we will study Bass numbers of local cohomology modules H I (R) supported on a squarefree monomial ideal I ⊆ R. Among them we are mainly interested in Lyubeznik numbers. We build a dictionary between the modules H I (R) and the minimal free resolution of the Alexander dual ideal I∨ that allow us to interpret Lyubeznik numbers as the obstruction to the acyclicity of the linear strands of I∨. The methods we develop also help us to give a bound for the injective dimension of the local cohomology modules in terms of the dimension of the small support.
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