Conic modules and global dimension of rings of differential operators
Eleonore Faber (University of Leeds)
Wednesday 18th October, 2017 16:00-17:00 Maths 311B
In this talk we consider a normal toric algebra R over a field k of arbitrary characteristic. The module M of p^e-th roots of R, where p and e are positive integers, is then the direct sum of so-called conic modules. With a combinatorial method we construct certain complexes of conic modules over R and explain how these yield projective resolutions of simple modules over the endomorphism ring End_R(M). Thus we obtain a bound on the global dimension of End_R(M), which shows that this endomorphism ring is a so-called noncommutative resolution of singularities (NCR) of R (or Spec(R)). If the characteristic of k is p>0, then this fact allows us to bound the global dimension of the ring of differential operators D(R). This is joint work with Greg Muller and Karen E. Smith.