Videos

Syzygies of torsion bundles and the geometry of the level l modular variety over M_g

Presenter
February 13, 2013
Keywords:
  • noncommutative algebra
  • representation theory
  • homological algebra
  • commutative algebra
  • resolutions of modules
  • syzygies
  • algebraic curves
  • moduli of curves
MSC:
  • 18G35
  • 18Gxx
  • 18-xx
  • 16Gxx
  • 18G10
  • 16E05
Abstract
In joint work with Chiodo, Eisenbud, and Schreyer, we formulate, and in some cases prove, three statements concerning the purity of the resolution of various rings one can attach to a generic curve of genus g and a torsion point of order 1 in its Jacobian. These statements can be viewed as analogues of Green's conjecture, and we verify them computationally for bounded genus. We then compute the cohomology class of the corresponding non-vanishing locus in the moduli space R_(g,l) of twisted level l curves of genus g and use this to derive results about the birational geometry of R_(g,l). For instance, we prove that R_(g,3) is a variety of general type when g>11. I will also discuss the surprising failure of the Prynn-Green conjecture for genera which are powers of 2.