scholarly journals The Hilbert scheme of space curves of small diameter

2006 ◽  
Vol 56 (5) ◽  
pp. 1297-1335 ◽  
Author(s):  
Jan Kleppe
2015 ◽  
Vol 26 (02) ◽  
pp. 1550017 ◽  
Author(s):  
Jan O. Kleppe ◽  
John C. Ottem

We study maximal families W of the Hilbert scheme, H(d, g)sc, of smooth connected space curves whose general curve C lies on a smooth surface S of degree s. We give conditions on C under which W is a generically smooth component of H(d, g)sc and we determine dim W. If s = 4 and W is an irreducible component of H(d, g)sc, then the Picard number of S is at most 2 and we explicitly describe, also for s ≥ 5, non-reduced and generically smooth components in the case Pic (S) is generated by the classes of a line and a smooth plane curve of degree s - 1. For curves on smooth cubic surfaces the first author finds new classes of non-reduced components of H(d, g)sc, thus making progress in proving a conjecture for such families.


1992 ◽  
Vol 03 (06) ◽  
pp. 799-807 ◽  
Author(s):  
PHILIPPE ELLIA ◽  
ANDRÉ HIRSCHOWITZ ◽  
EMILIA MEZZETTI

2012 ◽  
Vol 62 (6) ◽  
pp. 2099-2130 ◽  
Author(s):  
Jan Kleppe
Keyword(s):  

2003 ◽  
Vol 171 ◽  
pp. 51-83 ◽  
Author(s):  
Sébastien Guffroy

AbstractSince J.Wahl ([27]), it is known that degree d plane curves having some fixed numbers of nodes and cusps as its only singularities can be represented by a scheme, let say H, which can be singular. In Wahl’s example, H is singular along a subscheme F but the induced reduced scheme Hred is smooth along F. In this work, we construct explicitly a family of plane curves with nodes and cusps which are represented by singular points of Hred.To this end, we begin to show that the Hilbert scheme of smooth and connected space curves of degree 12 and genus 15 is irreducible and generically smooth. It follows that it is singular along a hypersurface (3.10). This example is minimal in the sense that the Hilbert scheme of smooth and connected space curves is regular in codimension 1 for d < 12 (B.2). Finally we construct our plane curves from the space curves represented by points of this hypersurface (4.7).


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