Mass varying neutrinos with different quintessence potentials

Abstract

The mass-varying neutrino scenario is analyzed for three trial quintessence potentials (Ferreira-Joyce, inverse exponential, and thawing oscillating). The neutrino mass is generated via Yukawa coupling to the scalar field which represents dark energy. The inverse exponential and oscillating potentials are shown to successfully generate the neutrino masses in the range m ∼ 10-2-10-3 eV and to yield the current dark energy density in the regime of the late-time acceleration of the Universe. Depending on the choice of potentials, the acceleration could occur in two different regimes: (1) the regime of instability, and (2) the stable regime. The first regime of instability is after the Universe underwent a first-order transition and is rolling toward the new stable vacuum. The imaginary sound velocity c2 s < 0 in this regime implies growing fluctuations of the neutrino density (clustering). In the second regime, the Universe smoothly changes its stable states via a continuous transition. Since c2 s > 0, the neutrino density is stable. For all cases the predicted late-time acceleration of the Universe is asymptotically very close to that of the ΛCDM model. Further extensions of the theory to modify the neutrino sector of the Standard Model and to incorporate inflation are also discussed. It is also shown that in the stable regimes where the neutrino mass is given by the minimum of the thermodynamic potential, the tree-level dynamics of the scalar field is robust with respect to one-loop bosonic and fermionic corrections to the potential.

Observational Constraints on Dynamical Dark Energy Models

“…These works predict a time-dependent mass for dark matter particles and neutrinos. It has been shown in the following work [239,240] that it is possible to simultaneously obtain the values of the late-time evolution of the universe (w → −1, V(ϕ) ∼ M 4 ∼ Λ), asymptotically close to that of the ΛCDM model, as well as the dark-energy-generated neutrino masses consistent with the observations for several dark energy potentials coupled to the fermionic field.…”

“…The models analyzed in [239,240] are toy models since only a single fermionic species coupled to the scalar field is considered. An important and promising direction of the future work, aiming to reveal the origins of the dark sector of the universe and the neutrino mass generation, appears to be an approach unifying the scalar field(s) coupled to the matter fields of the Standard Model.…”

“…A significant drawback of this model is the absence of a convincing explanation for the onset of the interaction of dark energy and matter at the epoch of transition from the decelerated to the accelerated expansion of the universe. The thermal quantum-field theory treatment of the quintessence dark energy coupled to the matter field shows that one can consistently recover different expansion regimes of the universe, including the late-time acceleration; however, more work is needed to relate the matter field to a viable dark matter candidate [239,240].…”

Observational Constraints on Dynamical Dark Energy Models

“…A significant drawback of this model is the absence of a convincing explanation for the onset of the interaction of dark energy and matter at the epoch of transition from the decelerated to the accelerated expansion of the universe. The thermal quantum-field theory treatment of the quintessence dark energy coupled to the matter field shows that one can consistently recover different expansion regimes of the universe, including the late-time acceleration, however more work is needed to relate the matter field to a viable dark matter candidate [191,192].…”