Numerical approaches for some Nonlinear Eigenvalue Problems

In this article we are interested for the numerical study of nonlinear eigenvalue problems. We begin with a review of theoretical results obtained by functional analysis methods, especially for the Schrodinger pencils. Some recall are given for the pseudospectra. Then we present the numerical methods and results obtained for eigenvalues computation with spectral methods and finite difference discretization, in infinite or bounded domains. Comparison with theoretical results is done. The main difficulty here is that we have to compute eigenvalues of strongly non-self-adjoint operators which are very unstable.