Title    name
2009 Algebraic Geometry Workshop at KAIST
  Speaker Chikashi Miyazaki
  Date 2009-04-10
  Place KAIST
  File  의 1 번째 Real Media 동영상입니다.
Abstract : I will talk on the next extremal case for a Castelnuovo-type bound reg $C leq |(deg C-1)/$ co dim $C|+ max{k(C), 1}$ for the Castelnuovo-Mumford regularity for a nondegenerate projective curve $C$, where $k(C)$ is an invariant which measures the deficiency of the Hartshorne-Rao module of $C$. Also, in highier dimensional cases, for a nondegenerate projective Buchsbaum variety $V$, a bound reg $V leq lceil(deg V-1)/$ co dim $V lceil + 1$ gives the corrsponding next extremal variety. The socle lemma by Huneke-Ulrich and a result from the Castelnuovo theory by Eisenbud-Harris plays an important role for the proof.