1999/04/08 by Indranil Biswas, Biswas, Indranil, Leticia Brambila-Paz +1
Mathematics · #Algebraic Geometry (math.AG) #FOS: Mathematics #math.AG
paper · pdf · doi:10.48550/arxiv.math/9904033
AMS-LaTex file
arxiv created 1999/04/08 · arxiv updated 2009/11/30
Let X be a compact connected Riemann surface of genus g, with g≥ 2, and \cal Mξ a smooth moduli space of fixed determinant semistable vector bundles of rank n, with n≥ 2, over X. Take a smooth anticanonical divisor D on \cal Mξ. So D is a Calabi-Yau variety. We compute the number of moduli of D, namely dim H1(D, TD), to be 3g-4 + dim H0(\cal Mξ, K-1_\cal Mξ). Denote by \cal N the moduli space of all such pairs (X',D'), namely D' is a smooth anticanonical divisor on a smooth moduli space of semistable vector bundles over the Riemann surface X'. It turns out that the Kodaira-Spencer map from the tangent space to \cal N, at the point represented by the pair (X,D), to H1(D, TD) is an isomorphism. This is proved under the assumption that if g =2, then n≠ 2,3, and if g=3, then n≠ 2.