The implicit equation of a multigraded hypersurface

In this article we analyze the implicitization problem of the image of a rational map φ:X[U+21E2]Pn, with X a toric variety of dimension n-1 defined by its Cox ring R. Let I:=(f0, ..., fn) be n+1 homogeneous elements of R. We blow-up the base locus of φ, V(I), and we approximate the Rees algebra Ree...

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Publicado: 2011
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218693_v348_n1_p381_Botbol
http://hdl.handle.net/20.500.12110/paper_00218693_v348_n1_p381_Botbol
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spelling paper:paper_00218693_v348_n1_p381_Botbol2023-06-08T14:42:26Z The implicit equation of a multigraded hypersurface Approximation complex Castelnuovo-Mumford regularity Elimination theory Graded algebra Graded ring Hypersurfaces Implicit equation Implicitization Koszul complex Multigraded algebra Multigraded ring Resultant Toric variety In this article we analyze the implicitization problem of the image of a rational map φ:X[U+21E2]Pn, with X a toric variety of dimension n-1 defined by its Cox ring R. Let I:=(f0, ..., fn) be n+1 homogeneous elements of R. We blow-up the base locus of φ, V(I), and we approximate the Rees algebra ReesR(I) of this blow-up by the symmetric algebra SymR(I). We provide under suitable assumptions, resolutions Z for SymR(I) graded by the divisor group of X, Cl(X), such that the determinant of a graded strand, det((Z)μ), gives a multiple of the implicit equation, for suitable μ∈Cl(X). Indeed, we compute a region in Cl(X) which depends on the regularity of SymR(I) where to choose μ. We also give a geometrical interpretation of the possible other factors appearing in det((Z)μ). A very detailed description is given when X is a multiprojective space. © 2011 Elsevier Inc. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218693_v348_n1_p381_Botbol http://hdl.handle.net/20.500.12110/paper_00218693_v348_n1_p381_Botbol
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Approximation complex
Castelnuovo-Mumford regularity
Elimination theory
Graded algebra
Graded ring
Hypersurfaces
Implicit equation
Implicitization
Koszul complex
Multigraded algebra
Multigraded ring
Resultant
Toric variety
spellingShingle Approximation complex
Castelnuovo-Mumford regularity
Elimination theory
Graded algebra
Graded ring
Hypersurfaces
Implicit equation
Implicitization
Koszul complex
Multigraded algebra
Multigraded ring
Resultant
Toric variety
The implicit equation of a multigraded hypersurface
topic_facet Approximation complex
Castelnuovo-Mumford regularity
Elimination theory
Graded algebra
Graded ring
Hypersurfaces
Implicit equation
Implicitization
Koszul complex
Multigraded algebra
Multigraded ring
Resultant
Toric variety
description In this article we analyze the implicitization problem of the image of a rational map φ:X[U+21E2]Pn, with X a toric variety of dimension n-1 defined by its Cox ring R. Let I:=(f0, ..., fn) be n+1 homogeneous elements of R. We blow-up the base locus of φ, V(I), and we approximate the Rees algebra ReesR(I) of this blow-up by the symmetric algebra SymR(I). We provide under suitable assumptions, resolutions Z for SymR(I) graded by the divisor group of X, Cl(X), such that the determinant of a graded strand, det((Z)μ), gives a multiple of the implicit equation, for suitable μ∈Cl(X). Indeed, we compute a region in Cl(X) which depends on the regularity of SymR(I) where to choose μ. We also give a geometrical interpretation of the possible other factors appearing in det((Z)μ). A very detailed description is given when X is a multiprojective space. © 2011 Elsevier Inc.
title The implicit equation of a multigraded hypersurface
title_short The implicit equation of a multigraded hypersurface
title_full The implicit equation of a multigraded hypersurface
title_fullStr The implicit equation of a multigraded hypersurface
title_full_unstemmed The implicit equation of a multigraded hypersurface
title_sort implicit equation of a multigraded hypersurface
publishDate 2011
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218693_v348_n1_p381_Botbol
http://hdl.handle.net/20.500.12110/paper_00218693_v348_n1_p381_Botbol
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