Resolutions of ideals of fat points with support in a hyperplane

dc.creatorFatabbi, Giuliana
dc.creatorHarbourne, Brian
dc.creatorLorenzini, Anna
dc.date2005-02-19
dc.date2005-07-11
dc.date.accessioned2026-07-07T05:17:11Z
dc.date.available2026-07-07T05:17:11Z
dc.descriptionOur results concern minimal graded free resolutions of fat point ideals for points in a hyperplane. Suppose, for example, that I(m,d) is the ideal defining r given points of multiplicity m in the projective space P^d. Assume that the given points lie in a hyperplane P^{d-1} in P^d, and that the ground field k is algebraically closed of characteristic 0. We give an explicit minimal graded free resolution of I(m,d) in k[P^d] in terms of the minimal graded free resolutions of the ideals I(j,d-1) in k[P^{d-1}] with j < m+1. As a corollary, we give the following formula for the Poincare polynomial P_{m,d} of I(m,d) in terms of the Poincare polynomials P_{j,d-1} of I(j,d-1): P_{m,d} = (1 + XT)(Σ_{0<j\le m} T^{m-j}(P_{j,d-1} - 1)) + 1 + XT^m.
dc.description10 pages; to appear in Proc. Amer. Math. Soc.; some expositional changes; added a reference to paper of Geramita, Migliore and Sabourin (math.AC/0411445)
dc.identifierhttps://arxiv.org/abs/math/0502418
dc.identifierhttp://arxiv.org/abs/math/0502418
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/74257
dc.subjectAlgebraic Geometry
dc.subjectCommutative Algebra
dc.subject14Q99; 13D02
dc.titleResolutions of ideals of fat points with support in a hyperplane
dc.typetext

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