symmetric Schrödinger operators: reality of the perturbed eigenvalues.
Perturbation of an eigen-value from a dense point spectrum : a general Floquet hamiltonian
Perturbative expansions in quantum mechanics
We prove a analytic versal deformation theorem in the Heisenberg algebra. We define the spectrum of an element in the Heisenberg algebra. The quantised version of the Morse lemma already shows that the perturbation series arising in a perturbed harmonic oscillator become analytic after a formal Borel transform.
Perturbative treatment of the evolution operator associated with Raman couplings.
Puits multiples (d'après des travaux avec B. Helffer)
Puits multiples pour l'opérateur de Dirac