Publication Date:
2014-01-18
Description:
Let C be a 2-connected projective curve either reduced with planar singularities or contained in a smooth algebraic surface and let S be a subcanonical cluster (that is, a zero-dimensional scheme such that the space H 0 ( C , I S K C ) contains a generically invertible section). Under some general assumptions on S or C , we show that h 0 ( C , I S K C )≤ p a ( C )–1/2 deg ( S ) and if equality holds then either S is trivial or C is honestly hyperelliptic or 3-disconnected. As a corollary, we give a generalization of Clifford's theorem for reduced curves with planar singularities.
Print ISSN:
0024-6115
Electronic ISSN:
1460-244X
Topics:
Mathematics
Permalink