Abstract or Keywords
We study the energy distribution of harmonic 1-forms on a compact hyperbolic Riemann surface
S
where a short closed geodesic is pinched. If the geodesic separates the surface into two parts, then the Jacobian variety of
S
develops into a variety that splits. If the geodesic is nonseparating then the Jacobian degenerates. The aim of this work is to get insight into this process and give estimates in terms of geometric data of both the initial surface
S
and the final surface, such as its injectivity radius and the lengths of geodesics that form a homology basis. The Jacobians in this paper are represented by Gram period matrices. As an invariant we introduce new families of symplectic matrices that compensate for the lack of full dimensional Gram-period matrices in the noncompact case.