Betti numbers of space curves bounded by Hilbert functions

Authors

  • Renato Maggioni
  • Alfio Ragusa

Keywords:

Dubreil's theorem, Betti numbers, Hilbert function, Bilinked curves

Abstract

We study relationships between Hilbert functions and graded Betti numbers of two space curves C and C_0 bilinked by a sequence of basic double linkages; precisely we obtain bounds for the graded Betti numbers of C by means of the Hilbert functions of the two curves and the graded Betti numbers of C_0 . On the other hand for every set of integers satisfying these bounds we can construct a curve with these integers as its graded Betti numbers. As a consequence we get a Dubreil-type theorem for a curve C which strongly dominates C_0 at height h which is exactly the Amasaki bound for Buchsbaum curves. Moreover we deduce for biliaison classes of Buchsbaum curves that a strong Lazarsfeld-Rao property holds.

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Published

1998-01-01

Issue

Section

Articoli