This paper studies some
geometric aspects of moduli of curves ℳg, using as a tool the deformation formula of
holomorphic one-forms. Quasi-isometry guarantees the L2 convergence of deformation
of holomorphic one-forms, which is a kind of global result. After giving the period
map a full expansion, we can also write out the Siegel metric, curvature and second
fundamental form of a nonhyperelliptic locus of ℳg in a quite detailed manner, while
gaining some understanding of a totally geodesic manifold in a nonhyperelliptic
locus.
Keywords
moduli of Riemann surfaces, Teichmüller theory, period
matrices, variation of Hodge structures, differentials on
Riemann surfaces