Extended Noether-Lefschetz loci
نویسندگان
چکیده
We compute class groups of very general normal surfaces in P3 C containing an arbitrary base locus Z, thereby extending the classic Noether-Lefschetz theorem (when Z is empty). Our method is an adaptation of Griffiths and Harris’ degeneration proof, simplified by a cohomology and base change argument. We give some applications to computing Picard groups. Dedicated to Robin Hartshorne on his 70th birthday
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تاریخ انتشار 2009