Mathematics Colloquia and Seminars
Return to Colloquia & Seminar listing
Divisorial linear algebra over normal affine semigroup ringsAlgebra & Discrete Mathematics
|Speaker: ||Winfried Bruns, Universitat Osnabrueck Germany|
|Location: ||0 Kerr|
|Start time: ||Fri, Feb 28 2003, 12:10PM|
In joint work with J. Gubeladze we have explored the ``linear algebra''
properties of divisorial ideals over normal semigroup rings. In invariant
theory these ideals appear as modules of semi-invariants of the actions of
algebraic tori. The properties and invariants to be discussed are, among
other things, the Cohen-Macaulayness and the number of generators. In
particular we show that there exist, up to isomorphism, only finitely many
Cohen-Macaulay (divisorial) ideals.