Active-sterile neutrino mixing in the ISS(p,q) inverse seesaw models

Abstract

A class of models with inverse seesaw (ISS) mechanism is considered for arbitrary numbers p and q of new neutral fermions for each generation of leptons. The models containing a candidate particle for the role of warm dark matter are sorted using the inversion technique of an arbitrary block matrix in terms of Schur complement. Studies of the neutrino mass hierarchies and active-sterile neutrino mixing scenarios in the ISS parameter space for the general case of Casas-Ibarra diagonalization make it possible to identify a class of models that satisfy the last strong constraints from NuSTAR, XMM-Newton, and eROSITA experiments for keV-scale sterile neutrino dark matter particles.

Comments: 23 pages, 4 figures