Mixed configurations of tensor-multi-scalar solitons and neutron stars

Abstract

In the present paper we consider special classes of massive tensor-multi-scalar theories of gravity whose target space metric admits Killing field(s) with a periodic flow. For such tensor-multi-scalar theories we show that there exist mixed configurations of tenor-multi-scalar solitons and relativistic (neutron) stars. The influence of the curvature of the target space on the structure of the mixed configurations is studied for two explicit scalar-tensor theories. The stability of the obtained compact objects is examined and it turns out that the stability region spans to larger central energy densities and central values of the scalar field compared to the pure neutron stars or the pure tensor-multi-scalar solitons.