Spectral monodromy of non selfadjoint operators

Quang Sang Phan (1)

1 IRMAR - Institut de Recherche Mathématique de Rennes

We propose to build a combinatorial invariant, called the spectral monodromy, from the spectrum of a single non-selfadjoint h-pseudodifferential operator with two degrees of freedom in the semi-classical limit. Our inspiration comes from the quantum monodromy defined for the joint spectrum of an integrable system of n commuting selfadjoint h-pseudodifferential operators, given by S. Vu Ngoc. The first simple case that we treat in this work is a normal operator. In this case, the discrete spectrum can be identified with the joint spectrum of an integrable quantum system. The second more complex case we propose is a small perturbation of a selfadjoint operator with a classical integrability property. We show that the discrete spectrum (in a small band around the real axis) also has a combinatorial monodromy. The difficulty here is that we do not know the description of the spectrum everywhere, but only in a Cantor type set. In addition, we also show that the monodromy can be identified with the classical monodromy defined by J. Duistermaat.

Mots clés: spectral analysis; pseudo-differential operators; Birkhoff normal form; monodromy; asymptotic spectral; quantum mechanics; classical mechanics; symplectic geometry.; symplectic geometry; Semiclassical analysis; microlocal analysis; Hamiltonian system; integrable system

Domaines: Physique mathématique [math-ph]

Quang Sang Phan. Spectral monodromy of non selfadjoint operators. 2012. ⟨hal-00766411v1⟩