... and Schrödinger operators.
A Complex Characterization of the Schwartz Space D (...).
A counterexample to the L² estimate //Xyu//...C(//X...u// + //Y...u// + //u//).
A criterion for discrete spectra of partial differential operators
A density theorem about some system
A general approximation theorem of Whitney type.
We show that Whitney?s approximation theorem holds in a general setting including spaces of (ultra)differentiable functions and ultradistributions. This is used to obtain real analytic modifications for differentiable functions including optimal estimates. Finally, a surjectivity criterion for continuous linear operators between Fréchet sheaves is deduced, which can be applied to the boundary value problem for holomorphic functions and to convolution operators in spaces of ultradifferentiable functions...
A generalized 2-D Poincaré inequality.
A Geometric Construction of the Discrete Series for Semisimple Lie Groups.
A homogeneous Dirichlet problem for a nonlinear partial differential equation in an anisotropic Sobolec space.
A minimax principle for eigenvalues in spectral gaps: Dirac operators with Coulomb potentials.
A model of atomic radiation
A new phase space localization technique with application to the sum of negative eigenvalues of Schrödinger operators
A note on Dirac operators
A note on singular and degenerate abstract equations
Si considera l’equazione astratta , dove
A note on the Rellich formula in Lipschitz domains.
Let L be a symmetric second order uniformly elliptic operator in divergence form acting in a bounded Lipschitz domain Ω of RN and having Lipschitz coefficients in Ω. It is shown that the Rellich formula with respect to Ω and L extends to all functions in the domain D = {u ∈ H01(Ω); L(u) ∈ L2(Ω)} of L. This answers a question of A. Chaïra and G. Lebeau.
A Paley-Wiener type theorem for generalized non-quasianalytic classes
Let P be a hypoelliptic polynomial. We consider classes of ultradifferentiable functions with respect to the iterates of the partial differential operator P(D) and prove that such classes satisfy a Paley-Wiener type theorem. These classes and the corresponding test spaces are nuclear.
A partial differential operator which is surjective on Gevrey classes with 1 ≤ d < 2 and d ≥ 6 but not for 2 ≤ d < 6
It is shown that the partial differential operator is surjective if 1 ≤ d < 2 or d ≥ 6 and not surjective for 2 ≤ d < 6.
A remark on the differential equations on the sphere
A result on the well posedness of the Cauchy problem for a class of hyperbolic operators with double characteristics
A semilinear equation in