A rapid convergence method for a singular perturbation problem
A rational spectral problem in fluid-solid vibration.
A remark on Schrödinger's equation with a short range potential
A remark on two dimensional periodic potentials.
A result on the bifurcation from the principal eigenvalue of the -Laplacian.
A scattering theory for automorphic functions
A second eigenvalue bound for the Dirichlet-Schrödinger equation with a radially symmetric potential.
A selfadjoint hyperbolic boundary-value problem.
A semi-classical picture of quantum scattering
A sharp result on the poles localization for a Gevrey convex body
In this talk we extend to Gevrey-s obstacles with a result on the poles free zone due to J. Sjöstrand [8] for the analytic case.
A Simple Example of Localized Parametric Resonance for the Wave Equation
2000 Mathematics Subject Classification: 35L05, 35P25, 47A40.The problem studied here was suggested to us by V. Petkov. Since the beginning of our careers, we have benefitted from his insights in partial differential equations and mathematical physics. In his writings and many discussions, the conjuction of deep analysis and specially interesting problems has been a source inspiration for us.The research of J. Rauch is partially supported by the U.S. National Science Foundation under grant NSF-DMS-0104096...
A spectral estimate for the Dirac operator on Riemannian flows
We give a new upper bound for the smallest eigenvalues of the Dirac operator on a Riemannian flow carrying transversal Killing spinors. We derive an estimate on both Sasakian and 3-dimensional manifolds, and partially classify those satisfying the limiting case. Finally, we compare our estimate with a lower bound in terms of a natural tensor depending on the eigenspinor.
A Spectral Gap Theorem for Dirac Operators with Central Field.
A spectral problem with an indefinite weight for an elliptic system.
A spectral study of an infinite axisymmetric elastic layer
We present here a theoretical study of eigenmodes in axisymmetric elastic layers. The mathematical modelling allows us to bring this problem to a spectral study of a sequence of unbounded self-adjoint operators , , in a suitable Hilbert space. We show that the essential spectrum of is an interval of type and that, under certain conditions on the coefficients of the medium, the discrete spectrum is non empty.
A spectral study of an infinite axisymmetric elastic layer
We present here a theoretical study of eigenmodes in axisymmetric elastic layers. The mathematical modelling allows us to bring this problem to a spectral study of a sequence of unbounded self-adjoint operators An, , in a suitable Hilbert space. We show that the essential spectrum of An is an interval of type and that, under certain conditions on the coefficients of the medium, the discrete spectrum is non empty.
A Superconvergence result for mixed finite element approximations of the eigenvalue problem
In this paper, we present a superconvergence result for the mixed finite element approximations of general second order elliptic eigenvalue problems. It is known that a superconvergence result has been given by Durán et al. [Math. Models Methods Appl. Sci. 9 (1999) 1165–1178] and Gardini [ESAIM: M2AN 43 (2009) 853–865] for the lowest order Raviart-Thomas approximation of Laplace eigenvalue problems. In this work, we introduce a new way to derive the superconvergence of general second order elliptic...
A Superconvergence result for mixed finite element approximations of the eigenvalue problem∗
In this paper, we present a superconvergence result for the mixed finite element approximations of general second order elliptic eigenvalue problems. It is known that a superconvergence result has been given by Durán et al. [Math. Models Methods Appl. Sci. 9 (1999) 1165–1178] and Gardini [ESAIM: M2AN 43 (2009) 853–865] for the lowest order Raviart-Thomas approximation of Laplace eigenvalue problems. In this work, we introduce a new way to derive the superconvergence of general second order elliptic...
A tauberian theorem in quantum mechanical inverse scattering theory
A Tour Through -invariants: from Nash’s Embedding Theorem to Ideal Immersions, Best Ways of Living and Beyond