m at h . A G ] 1 9 A ug 2 00 6 INTERSECTION NUMBERS ON M g , n AND AUTOMORPHISMS OF STABLE CURVES
نویسندگان
چکیده
Due to the orbifold singularities, the intersection numbers on the moduli space of curves Mg,n are in general rational numbers rather than integers. We study the properties of the denominators of these intersection numbers and their relationship with the orders of automorphism groups of stable curves. We also present a conjecture about a multinomial type numerical property for a general class of Hodge integrals.
منابع مشابه
9 A ug 2 00 6 INTERSECTION NUMBERS ON M g , n AND AUTOMORPHISMS OF STABLE CURVES
Due to the orbifold singularities, the intersection numbers on the moduli space of curves Mg,n are in general rational numbers rather than integers. We study the properties of the denominators of these intersection numbers and their relationship with the orders of automorphism groups of stable curves. We also present a conjecture about the numerical property for a general class of Hodge integrals.
متن کاملA ug 2 00 6 INTERSECTION NUMBERS ON M g , n AND AUTOMORPHISMS OF STABLE CURVES
Due to the orbifold singularities, the intersection numbers on the moduli space of curves Mg,n are in general rational numbers rather than integers. We study the properties of the denominators of these intersection numbers and their relationship with the orders of automorphism groups of stable curves. We also present a conjecture about the numerical property for a general class of Hodge integrals.
متن کاملOn Marginal Automorphisms of a Group Fixing the Certain Subgroup
Let W be a variety of groups defined by a set W of laws and G be a finite p-group in W. The automorphism α of a group G is said to bea marginal automorphism (with respect to W), if for all x ∈ G, x−1α(x) ∈ W∗(G), where W∗(G) is the marginal subgroup of G. Let M,N be two normalsubgroups of G. By AutM(G), we mean the subgroup of Aut(G) consistingof all automorphisms which centralize G/M. AutN(G) ...
متن کاملVarieties without Extra Automorphisms I: Curves
For any field k and integer g ≥ 3, we exhibit a curve X over k of genus g such that X has no non-trivial automorphisms over k. 1. Statement of the result Let k be a field, and let p be its characteristic, which may be zero. All our curves are smooth, projective, and geometrically integral over k. If X is a curve over k, let AutX denote the group of automorphisms of X over k. Hurwitz stated that...
متن کاملun 2 00 7 Profinite complexes of curves , their automorphisms and anabelian properties of moduli stacks of curves
Let M g,[n] , for 2g − 2 + n > 0, be the Deligne-Mumford (briefly D-M) moduli stack of smooth curves of genus g labeled by n unordered distinct points. The main result of the paper is that a finite, connectedétale cover M λ of M g,[n] , defined over a sub-p-adic field k, is " almost " anabelian in the sense conjectured by Grothendieck for curves and their moduli spaces.
متن کامل