Spectral decomposition for non-selfadjoint singular differential operators

On the Spectral Properties of Degenerate Non-selfadjoint Elliptic systems of Differential Operators

Spectral instability for non-selfadjoint operators∗

We describe a recent result of M. Hager, stating roughly that for nonselfadjoint ordinary differential operators with a small random perturbation we have a Weyl law for the distribution of eigenvalues with a probability very close to 1.

Spectral monodromy of non selfadjoint operators

We propose to build in this paper 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 ...

Diophantine tori and spectral asymptotics for non-selfadjoint operators

We study spectral asymptotics for small non-selfadjoint perturbations of selfadjoint h-pseudodifferential operators in dimension 2, assuming that the classical flow of the unperturbed part possesses several invariant Lagrangian tori enjoying a Diophantine property. We get complete asymptotic expansions for all eigenvalues in certain rectangles in the complex plane in two different cases: in the...

on the spectral properties of degenerate non-selfadjoint elliptic systems of differential operators