English

A non-vanishing result for the tautological ring of {\cal M}_g

Algebraic Geometry 2016-09-07 v1

Abstract

Looijenga recently proved that the tautological ring of M_g vanishes in degree d>g-2 and is at most one-dimensional in degree g-2, generated by the class of the hyperelliptic locus. Here we show that K_{g-2} is non-zero on M_g. The proof uses the Witten conjecture, proven by Kontsevich. With similar methods, we expect to be able to prove some (possibly all) of the identities in degree g-2 in the tautological ring that are part of the author's conjectural explicit description of the ring.

Keywords

Cite

@article{arxiv.math/9711219,
  title  = {A non-vanishing result for the tautological ring of {\cal M}_g},
  author = {Carel F. Faber},
  journal= {arXiv preprint arXiv:math/9711219},
  year   = {2016}
}