Cosmic Coincidence with a new Type of Dark Matter

TL;DR

This paper proposes a new dark matter model where neutrinos in a special state called CLEP evolve with the universe's expansion, mimicking dark energy and affecting cosmic dynamics.

Contribution

It introduces a novel fermion field theory with CLEP states, linking neutrino properties to cosmological expansion and dark energy phenomena.

Findings

Neutrinos in CLEP states increase mass as universe expands

Dark matter in CLEP states exhibits negative pressure similar to dark energy

Total universe energy density is lower with CLEP neutrinos than without

Abstract

A field theory is proposed where the regular fermionic matter and the dark fermionic matter are different states of the same "primordial" fermion fields. In regime of the fermion densities typical for normal particle physics, the primordial fermions split into three families identified with regular fermions. When fermion energy density becomes comparable with dark energy density, the theory allows new type of states. The possibility of such Cosmo-Low Energy Physics (CLEP) states is demonstrated by means of solutions of the field theory equations describing FRW universe filled by homogeneous scalar field and uniformly distributed nonrelativistic neutrinos. Neutrinos in CLEP state are drawn into cosmological expansion by means of dynamically changing their own parameters. One of the features of the fermions in CLEP state is that in the late time universe their masses increase as a^{3/2} (a=a(t) is the scale factor). The energy density of the cold dark matter consisting of neutrinos in CLEP state scales as a sort of dark energy; this cold dark matter possesses negative pressure and for the late time universe its equation of state approaches that of the cosmological constant. The total energy density of such universe is less than it would be in the universe free of fermionic matter at all. The (quintessence) scalar field is coupled to dark matter but its coupling to regular fermionic matter appears to be extremely strongly suppressed.