spontaneously-broken chiral symmetry

We present and discuss the properties and the main results of a cosmological model with a spontaneously-broken chiral symmetry. The model contains and relates dynamically, two spin-zero fields. The scalar field can provide the dynamical basis for inflation in the early universe. The pseudoscalar, Goldstone field can provide an early, small residual vacuum energy density, the absolute value of which we estimate to be similar to the present, empirically small vacuum energy density. The small energy scale for this effective cosmological constant is estimated separately, by relating it dynamically to the empirical, small scale of neutrino mass. CP invariance is broken spontaneously. This provides a natural basis for the early generation of an antineutrino-neutrino asymmetry, whose magnitude we estimate, and find to be significant. Speculations concerning the existence and the dynamics of fields with spin-zero and positive parity play a central role in cosmological models [1–4]. Two such (scalar) fields are presently of particular interest in the construction of models for hypothetical inflation in the early universe [5], and for a presumed small cosmological constant [6,7] in the present epoch [3, 8]. In these considerations, one issue that is always present (but is often not explicitly stated), involves an effort to relate the existence of the hypothetical field to phenomena other than the single one for which it is postulated, i. e. either to provide a large vacuum energy density which drives early inflation [5], or to provide a small vacuum energy density which appears as an effective cosmological constant today [3]. One possibility involves considering the inflationary scalar field as the same field whose energy density gives a present effective cosmological constant [8]. A different possibility involves considering the cosmological-constant scalar field as a field which gives mass (varying with time) to dark-matter particles [4, 9]. These two possibilities invoke (homogeneous)