Caractérisation du spectre essentiel de l'opérateur de Schrödinger avec un champ magnétique
Characteristic properties of distributions associated with the wave group
Cheeger inequalities for unbounded graph Laplacians
We use the concept of intrinsic metrics to give a new definition for an isoperimetric constant of a graph. We use this novel isoperimetric constant to prove a Cheeger-type estimate for the bottom of the spectrum which is nontrivial even if the vertex degrees are unbounded.
Comparison of Perron and Floquet Eigenvalues in Age Structured Cell Division Cycle Models
We study the growth rate of a cell population that follows an age-structured PDE with time-periodic coefficients. Our motivation comes from the comparison between experimental tumor growth curves in mice endowed with intact or disrupted circadian clocks, known to exert their influence on the cell division cycle. We compare the growth rate of the model controlled by a time-periodic control on its coefficients with the growth rate of stationary models of the same nature, but with averaged coefficients....
Complete asymptotic expansions for eigenvalues of Dirichlet laplacian in thin three-dimensional rods
We consider the Dirichlet Laplacian in a thin curved three-dimensional rod. The rod is finite. Its cross-section is constant and small, and rotates along the reference curve in an arbitrary way. We find a two-parametric set of the eigenvalues of such operator and construct their complete asymptotic expansions. We show that this two-parametric set contains any prescribed number of the first eigenvalues of the considered operator. We obtain the complete asymptotic expansions for the eigenfunctions...
Complete asymptotic expansions for eigenvalues of Dirichlet Laplacian in thin three-dimensional rods*
We consider the Dirichlet Laplacian in a thin curved three-dimensional rod. The rod is finite. Its cross-section is constant and small, and rotates along the reference curve in an arbitrary way. We find a two-parametric set of the eigenvalues of such operator and construct their complete asymptotic expansions. We show that this two-parametric set contains any prescribed number of the first eigenvalues of the considered operator. We obtain the complete asymptotic expansions for the eigenfunctions...
Complétude asymptotique pour un modèle du transfert de charge
Comportamento asintotico dello spettro di operatori multi-quasi-ellittici di tipo Schrödinger
Comportement semi-classique du spectre des Hamiltoniens quantiques elliptiques
Comportement semi-classique du spectre des hamiltoniens quantiques hypoelliptiques
Confining quantum particles with a purely magnetic field
We consider a Schrödinger operator with a magnetic field (and no electric field) on a domain in the Euclidean space with a compact boundary. We give sufficient conditions on the behaviour of the magnetic field near the boundary which guarantees essential self-adjointness of this operator. From the physical point of view, it means that the quantum particle is confined in the domain by the magnetic field. We construct examples in the case where the boundary is smooth as well as for polytopes; These...
Continuum spectrum for the linearized extremal eigenvalue problem with boundary reactions
We study the semilinear problem with the boundary reaction where , , is a smooth bounded domain, is a smooth, strictly positive, convex, increasing function which is superlinear at , and is a parameter. It is known that there exists an extremal parameter such that a classical minimal solution exists for , and there is no solution for . Moreover, there is a unique weak solution corresponding to the parameter . In this paper, we continue to study the spectral properties of and show...
Control theory and high energy eigenfunctions
Convexity of the first eigenfunction of the drifting Laplacian operator and its applications.
Coverings, heat kernels and spanning trees.