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Almost global solutions for non hamiltonian semi-linear Klein-Gordon equations on compact revolution hypersurfaces

Jean-Marc Delort, Jérémie Szeftel (2005)

Journées Équations aux dérivées partielles

This paper is devoted to the proof of almost global existence results for Klein-Gordon equations on compact revolution hypersurfaces with non-Hamiltonian nonlinearities, when the data are smooth, small and radial. The method combines normal forms with the fact that the eigenvalues associated to radial eigenfunctions of the Laplacian on such manifolds are simple and satisfy convenient asymptotic expansions.

Almost sure Weyl asymptotics for non-self-adjoint elliptic operators on compact manifolds

William Bordeaux Montrieux, Johannes Sjöstrand (2010)

Annales de la faculté des sciences de Toulouse Mathématiques

In this paper, we consider elliptic differential operators on compact manifolds with a random perturbation in the 0th order term and show under fairly weak additional assumptions that the large eigenvalues almost surely distribute according to the Weyl law, well-known in the self-adjoint case.

An accuracy improvement in Egorov's theorem.

Jorge Drumond Silva (2007)

Publicacions Matemàtiques

We prove that the theorem of Egorov, on the canonical transformation of symbols of pseudodifferential operators conjugated by Fourier integral operators, can be sharpened. The main result is that the statement of Egorov's theorem remains true if, instead of just considering the principal symbols in Sm/Sm-1 for the pseudodifferential operators, one uses refined principal symbols in Sm/Sm-2, which for classical operators correspond simply to the principal plus the subprincipal symbol, and can generally...

An arithmetic Hilbert–Samuel theorem for pointed stable curves

Gerard Freixas i Montplet (2012)

Journal of the European Mathematical Society

Let ( 𝒪 , , F ) be an arithmetic ring of Krull dimension at most 1 , S = Spec ( 𝒪 ) and ( 𝒳 S ; σ 1 , ... , σ n ) a pointed stable curve. Write 𝒰 = 𝒳 j σ j ( S ) . For every integer k > 0 , the invertible sheaf ω 𝒳 / S k + 1 ( k σ 1 + ... + k σ n ) inherits a singular hermitian structure from the hyperbolic metric on the Riemann surface 𝒰 . In this article we define a Quillen type metric · Q on the determinant line λ k + 1 = λ ω 𝒳 / S k + 1 ( k ...

An error analysis of the multi-configuration time-dependent Hartree method of quantum dynamics

Dajana Conte, Christian Lubich (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

This paper gives an error analysis of the multi-configuration time-dependent Hartree (MCTDH) method for the approximation of multi-particle time-dependent Schrödinger equations. The MCTDH method approximates the multivariate wave function by a linear combination of products of univariate functions and replaces the high-dimensional linear Schrödinger equation by a coupled system of ordinary differential equations and low-dimensional nonlinear partial differential equations. The main result of this...

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