Phase transition patterns in relativistic and nonrelativistic multi-scalar-field models

We discuss the phenomena of symmetry nonrestoration and inverse symmetry breaking in the context of multi-scalar field theories at finite temperatures and present its consequences for the relativistic Higgs-Kibble multi-field sector as well as for a nonrelativistic model of hard core spheres. For relativistic scalar field models, it has been shown previously that temperature effects on the couplings do not alter, qualitatively, the phase transition pattern. Here, we show that for the nonrelativistic analogue of these models inverse symmetry breaking, as well as symmetry nonrestoration, cannot take place, at high temperatures, when the temperature dependence of the two-body couplings is considered. However, the temperature behavior in the nonrelativistic models allows for the appearance of reentrant phases.