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Colbois, Bruno
Nom
Colbois, Bruno
Affiliation principale
Fonction
Professeur ordinaire
Email
Bruno.Colbois@unine.ch
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Voici les éléments 1 - 10 sur 73
- PublicationMétadonnées seulementHilbert geometry for convex polygonal domains(2011-1-21)
; ;Vernicos, ConstantinVerovic, Patrick - PublicationMétadonnées seulementConvergence de variétés et convergence du spectre du Laplacien(1991-12-21)
; Courtois, Gilles - PublicationMétadonnées seulementUniform stability of the Dirichlet spectrum for rough perturbations(2013-10-29)
; ; Iversen, Mette - PublicationMétadonnées seulementEigenvalue control for a Finsler--Laplace operator(2013-5-1)
;Barthelmé, Thomas - PublicationMétadonnées seulementExtremal g-invariant eigenvalues of the Laplacian of g-invariant metrics(2008-12-21)
; ;Dryden, Emily BEl Soufi, AhmadThe study of extremal properties of the spectrum often involves restricting the metrics under consideration. Motivated by the work of Abreu and Freitas in the case of the sphere S-2 endowed with S-1-invariant metrics, we consider the subsequence lambda(G)(k) of the spectrum of a Riemannian manifold M which corresponds to metrics and functions invariant under the action of a compact Lie group G. If. G has dimension at least 1, we show that the functional lambda(G)(k) admits no extremal metric under volume-preserving G-invariant deforma- tions. If, moreover, M has dimension at least three, then the functional lambda(G)(k) is unbounded when restricted to any conformal class of G-invariant metrics of fixed volume. As a special case of this, we can consider the standard 0(n)-action on S-n; however, if we also require the metric to be induced by an embedding of S-n in Rn+1, we get an optimal upper bound on lambda(G)(k). - PublicationMétadonnées seulementSur la multiplicité de la première valeur propre de l'opérateur de Schrödinger avec champ magnétique sur la sphère S2(1998)
;Besson, Gérard; Courtois, GillesThe purpose of this text is to study the first eigenvalue of Schrodinger operator with magnetic field on the 2-sphere and to show that its multiplicity can be arbitrarily high. We also show that this multiplicity is bounded in terms of the curvature of the corresponding connection. This answers a question asked by Y. Colin de Verdiere. - PublicationMétadonnées seulementSur la multiplicité de la première valeur propre d'une surface de Riemann à courbure constante(1988)
; De Verdiere, Yves Colin - PublicationAccès libreExtremal eigenvalues of the Laplacian on Euclidean domains(2014-10-1)
; El Soufi, AhmadWe investigate properties of the sequences of extremal values that could be achieved by the eigenvalues of the Laplacian on Euclidean domains of unit volume, under Dirichlet and Neumann boundary conditions, respectively. In a second part, we study sequences of extremal eigenvalues of the Laplace-Beltrami operator on closed surfaces of unit area.