Search results for "rational cohomology class"
showing 3 items of 3 documents
A combinatorial algorithm related to the geometry of the moduli space of pointed curves
2002
As pointed out in Arbarello and Cornalba ( J. Alg. Geom. 5 (1996), 705–749), a theorem due to Di Francesco, Itzykson, and Zuber (see Di Francesco, Itzykson, and Zuber, Commun. Math. Phys. 151 (1993), 193–219) should yield new relations among cohomology classes of the moduli space of pointed curves. The coefficients appearing in these new relations can be determined by the algorithm we introduce in this paper.
Generalized Hodge classes on the moduli space of curves
2003
On the moduli space of curves we consider the cohomology classes which can be viewed as a generalization of the Hodge classes λi defined by Mumford in [6]. Following the methods used in this paper, we prove that these classes belong to the tautological ring of the moduli space.
Combinatorics of Mumford-Morita-Miller classes in low genus
2003
Here we use elementary combinatorial arguments to give explicit formulae and relations for some cohomology classes of moduli spaces of stable curves of low genus.