35 research outputs found
A Takayama-type extension theorem
We prove a theorem on the extension of holomorphic sections of powers of
adjoint bundles from submanifolds of complex codimension 1 having non-trivial
normal bundle. The first such result, due to Takayama, considers the case where
the canonical bundle is twisted by a line bundle that is a sum of a big and nef
line bundle and a -divisor that has kawamata log terminal
singularites on the submanifold from which extension occurs. In this paper we
weaken the positivity assumptions on the twisting line bundle to what we
believe to be the minimal positivity hypotheses. The main new idea is an
extension theorem of Ohsawa-Takegoshi type, in which twisted canonical sections
are extended from submanifolds with non-trivial normal bundle
Bergman interpolation on finite Riemann surfaces. Part I: Asymptotically Flat Case
We study the Bergman space interpolation problem of open Riemann surfaces
obtained from a compact Riemann surface by removing a finite number of points.
We equip such a surface with what we call an asymptotically flat conformal
metric, i.e., a complete metric with zero curvature outside a compact subset.
We then establish necessary and sufficient conditions for interpolation in
weighted Bergman spaces over asymptotically flat Riemann surfaces.Comment: The main result has been corrected: Sequences of density <1 are still
interpolating, but the density of an interpolation sequence is only shown to
be at most 1. The corrected result is sharp, by work of Borichev-Lyubarskii.
Also added a motivating section on Shapiro-Shields interpolation. Otherwise
typos and minor errors corrected. To appear in Journal d'Analys
Stable manifolds of holomorphic diffeomorphisms
We consider stable manifolds of a holomorphic diffeomorphism of a complex
manifold. Using a conjugation of the dynamics to a (non-stationary) polynomial
normal form, we show that typical stable manifolds are biholomorphic to complex
Euclidean space.Comment: 17 pages. Revised version. To appear in Inv. Mat