On the characteristic polynomial of an effective Hamiltonian

Abstract

The characteristic polynomial of the effective Hamiltonian for a general model has been discussed. It is found that, compared with the associated energy eigenvalues, this characteristic polynomial generally has better analytical properties and larger convergence radius when being expanded in powers of the interaction parameter, and hence is more suitable for a perturbation calculation. A form of effective Hamiltonian which has the same singularities (branch points) as such characteristic polynomial has also been constructed.

Cited by in corpus (4)

• Answer to the comment on "On the characteristic polynomial of an effective Hamiltonian''
• Fast recovery of parametric eigenvalues depending on several parameters and location of high order exceptional points
• Comment on: "On the characteristic polynomial of an effective Hamiltonian"
• On the effective secular equation