A generalization of the Strong Castelnuovo Lemma

dc.creatorGhezzi, Laura
dc.date2008-11-22
dc.date.accessioned2026-07-07T10:20:28Z
dc.date.available2026-07-07T10:20:28Z
dc.descriptionWe consider a set $X$ of distinct points in the $n$-dimensional projective space over an algebraically closed field $k$. Let $A$ denote the coordinate ring of $X$, and let $a_i(X)=\dim_k [{\rm Tor}_i^R(A,k)]_{i+1}$. Green's Strong Castelnuovo Lemma (SCL) shows that if the points are in general position, then $a_{n-1}(X)\neq 0$ if and only if the points are on a rational normal curve. Cavaliere, Rossi and Valla conjectured that if the points are not necessarily in general position the possible extension of the SCL should be the following: $a_{n-1}(X)\neq 0$ if and only if either the points are on a rational normal curve or in the union of two linear subspaces whose dimensions add up to $n$. In this work we prove the conjecture.
dc.identifierhttps://arxiv.org/abs/0811.3655
dc.identifierhttp://arxiv.org/abs/0811.3655
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/174859
dc.subjectCommutative Algebra
dc.subjectAlgebraic Geometry
dc.titleA generalization of the Strong Castelnuovo Lemma
dc.typetext

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