  There exist field theory models where the fermionic energy-momentum tensor
contains a term proportional to g_{\mu\nu}\bar{\Psi}\Psi which can be
responsible for a dark matter to dark energy transmutation. We study some
cosmological aspects of the new field theory effect where nonrelativistic
neutrinos are obliged to be drawn into cosmological expansion (by means of
dynamically changing their own parameters). This becomes possible as the
magnitudes of the cold neutrino and vacuum energy densities are comparable.
Some of the features of such Cosmo-Low Energy Physics (CLEP) state in the toy
model of the late time universe filled with homogeneous scalar field and
uniformly distributed nonrelativistic neutrinos: neutrino mass increases as
a^{3/2} ($a=a(t)$ is the scale factor); its energy density scales as a sort of
dark energy and its equation-of-state approaches w=-1 as a\to\infty; the total
energy density of such universe is less than it would be in the universe free
of fermionic matter at all. CLEP state can be realized in the framework of an
alternative gravity and matter fields theory. The latter is reduced to
canonical General Relativity when the fermionic matter built of the first two
fermion families is only taken into account. In this case also the 5-th force
problem is resolved automatically.
