2 00 8 Row Ideals and Fibers of Morphisms

نویسندگان

  • David Eisenbud
  • Bernd Ulrich
چکیده

Affectionately dedicated to Mel Hochster, who has been an inspiration to us for many years, on the occasion of his 65th birthday. Abstract We study the fibers of projective morphisms and rational maps. We characterize the analytic spread of a homogeneous ideal through properties of its syzygy matrix. Powers of linearly presented ideals need not be linearly presented, but we identify a weaker linearity property that is preserved by taking powers.

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تاریخ انتشار 2008