Postulation of general unions of lines and +lines in positive characteristic

E. Ballico

doi:10.4067/S0719-06462018000300031

DOI:

https://doi.org/10.4067/S0719-06462018000300031

Abstract

A +line is a scheme R âŠ‚ â„™^r with a line as its reduction L = R_red which is the union of L and a tangent vector v âŠˆ L with v_red âˆˆ L. Here we prove in arbitrary characteristic that for r â‰¥ 4 a general union of lines and +lines has maximal rank. We use the case r = 3 proved by myself in a previous paper and adapt the characteristic zero proof of the case r > 3 given in the same paper.

Keywords

Hilbert function , decorated line , disjoint unions of lines

E. Ballico Department of Mathematics, University of Trento, 38123 Povo (TN), Italy.

Pages: 31–36
Date Published: 2019-03-15
Vol. 20 No. 3 (2018)

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