  Fermion-boson stars are solutions of the gravitationally coupled
Einstein-Klein-Gordon-Hydrodynamic equations system. By means of methods
developed in previous works, we perform a stability analysis of fermion-boson
stars that include a quartic self-interaction in their bosonic part.
Additionally, we describe the complete structure of the stability and
instability regions of the space of free parameters, which we argue is
qualitatively the same for any value of the quartic self-interaction. The
relationship between the total mass of mixed stars and their general stability
is also discussed in terms of the structure identified within the stability
region.
