Displaying similar documents to “Spectral theory of corrugated surfaces”

Absolutely continuous spectrum and scattering in the surface Maryland model

François Bentosela, Philippe Briet, Leonid Pastur (2001)

Journées équations aux dérivées partielles

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We study the discrete Schrödinger operator H in 𝐙 d with the surface quasi periodic potential V ( x ) = g δ ( x 1 ) tan π ( α · x 2 + ω ) , where x = ( x 1 , x 2 ) , x 1 ∈ 𝐙 d 1 , x 2 ∈ 𝐙 d 2 , α ∈ 𝐑 d 2 , ω ∈ [ 0 , 1 ) . We first discuss a proof of the pure absolute continuity of the spectrum of H on the interval [ - d , d ] (the spectrum of the discrete laplacian) in the case where the components of α are rationally independent. Then we show that in this case the generalized eigenfunctions have the form of the “volume” waves, i.e. of the sum of the incident plane wave and reflected from the hyper-plane 𝐙 d 1 waves,...

Low regularity Cauchy theory for the water-waves problem: canals and swimming pools

T. Alazard, N. Burq, C. Zuily (2011)

Journées Équations aux dérivées partielles

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The purpose of this talk is to present some recent results about the Cauchy theory of the gravity water waves equations (without surface tension). In particular, we clarify the theory as well in terms of regularity indexes for the initial conditions as fin terms of smoothness of the bottom of the domain (namely no regularity assumption is assumed on the bottom). Our main result is that, following the approach developed in [, ], after suitable para-linearizations, the system can be arranged...

Multiple prime covers of the riemann sphere

Aaron Wootton (2005)

Open Mathematics

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A compact Riemann surface X of genus g≥2 which admits a cyclic group of automorphisms C q of prime order q such that X/C q has genus 0 is called a cyclic q-gonal surface. If a q-gonal surface X is also p-gonal for some prime p≠q, then X is called a multiple prime surface. In this paper, we classify all multiple prime surfaces. A consequence of this classification is a proof of the fact that a cyclic q-gonal surface can be cyclic p-gonal for at most one other prime p.

Weyl type upper bounds on the number of resonances near the real axis for trapped systems

Plamen Stefanov (2001)

Journées équations aux dérivées partielles

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We study semiclassical resonances in a box Ω ( h ) of height h N , N ≫ 1 . We show that the semiclassical wave front set of the resonant states (including the “generalized eigenfunctions”) is contained in the set 𝒯 of the trapped bicharacteristics. We also show that for a suitable self-adjoint reference operator P # ( h ) with discrete spectrum the number of resonances in Ω ( h ) is bounded by the number of eigenvalues of P # ( h ) in an interval a bit larger than the projection of Ω ( h ) on the real line. As an application,...

Spectral properties of non-self-adjoint operators

Johannes Sjöstrand (2009)

Journées Équations aux dérivées partielles

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This text contains a slightly expanded version of my 6 hour mini-course at the PDE-meeting in Évian-les-Bains in June 2009. The first part gives some old and recent results on non-self-adjoint differential operators. The second part is devoted to recent results about Weyl distribution of eigenvalues of elliptic operators with small random perturbations. Part III, in collaboration with B. Helffer, gives explicit estimates in the Gearhardt-Prüss theorem for semi-groups.