Friedmann cosmology with nonpositive-definite Higgs potentials

We consider classical aspects of the dynamics of scalar fields with nonpositive-definite potentials in the Friedmann cosmology. Such models appear as effective local models in the framework of nonlocal models related to string field theory. In an effective local approximation after a suitable field redefinition, the Higgs potential with a negative effective cosmological constant appears in these models. A special feature of considered models is an absence of the reheating phase, instead of which phase of regime change from expansion to contraction appears. We study the behavior of the model near the point of regime change.