All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 2 Next

Displaying 21 – 40 of 54

Showing per page

Spectral theory of translation surfaces : A short introduction

Luc Hillairet (2009/2010)

Séminaire de théorie spectrale et géométrie

We define translation surfaces and, on these, the Laplace operator that is associated with the Euclidean (singular) metric. This Laplace operator is not essentially self-adjoint and we recall how self-adjoint extensions are chosen. There are essentially two geometrical self-adjoint extensions and we show that they actually share the same spectrum

Stability of the bases and frames reproducing kernels in model spaces

Anton Baranov (2005)

Annales de l'institut Fourier

We study the bases and frames of reproducing kernels in the model subspaces K Θ 2 = H 2 ⊖ Θ H 2 of the Hardy class H 2 in the upper half-plane. The main problem under consideration is the stability of a basis of reproducing kernels k λ n ( z ) = ( 1 - Θ ( λ n ) ¯ Θ ( z ) ) / ( z - λ ¯ n ) under “small” perturbations of the points λ n . We propose an approach to this problem based on the recently obtained estimates of derivatives in the spaces K Θ 2 and produce estimates of admissible perturbations generalizing certain results of W.S. Cohn and E. Fricain.

Strengthened Moser’s conjecture, geometry of Grunsky coefficients and Fredholm eigenvalues

Samuel Krushkal (2007)

Open Mathematics

The Grunsky and Teichmüller norms ϰ(f) and k(f) of a holomorphic univalent function f in a finitely connected domain D ∋ ∞ with quasiconformal extension to ℂ ^ are related by ϰ(f) ≤ k(f). In 1985, Jürgen Moser conjectured that any univalent function in the disk Δ* = z: |z| > 1 can be approximated locally uniformly by functions with ϰ(f) < k(f). This conjecture has been recently proved by R. Kühnau and the author. In this paper, we prove that approximation is possible in a stronger sense, namely,...

Sur la multiplicité de la première valeur propre des surfaces riemanniennes

Gérard Besson (1980)

Annales de l'institut Fourier

Dans cet article nous donnons une borne supérieure pour la multiplicité des valeurs propres du laplacien sur une variété riemannienne compacte connexe de dimension 2, ne faisant intervenir que le genre de la surface.Nous améliorons des résultats de S.Y. Cheng par un raffinement de sa technique.Nous montrons ensuite que la multiplicité de la première valeur propre d’une sphère riemannienne (resp. un tore riemannien) est maximale dans le cas canonique, l’égalité n’étant pas caractéristique. Nous construisons...

Currently displaying 21 – 40 of 54