Related papers: Dark matter stability at fixed points in a modular…
In this paper, we study the phenomenology of a Dirac dark matter in the $L_\mu-L_\tau$ model and investigate the neutrino oscillation in the dark halo. Since dark matter couples to the muon neutrino and the tau neutrino with opposite sign…
The well-studied radiative model of neutrino mass through $Z_2$ dark matter is shown to be naturally realizable in the context of SU(6) grand unification. A recent new proposal based on U(1)_D dark matter is similarly accommodated in SU(7).…
Sterile neutrinos ($\nu_s$) that mix with active neutrinos ($\nu_a$) are interesting dark matter candidates with a rich cosmological and astrophysical phenomenology. In their simplest incarnation, their production is severely constrained by…
We present the Discrete Dark Matter mechanism (DDM) which consist on the stability of the dark matter from a spontaneous breaking of a flavor symmetry group into one of its subgroups. Here we present the inclusion of the quarks on this…
The modular $A_4$ symmetry with three moduli is investigated. We assign different moduli to charged leptons, neutrinos, and quarks. We analyze these moduli at their fixed points where a residual symmetry exists. We consider two…
Multi-Higgs models equipped with global symmetries produce scalar dark matter (DM) candidates stabilized by the unbroken symmetry. It is remarkable that a conserved CP symmetry can also stabilize DM candidates, provided it is a CP symmetry…
We study the phenomenological implications of the modular symmetry $\Gamma(3) \simeq A_4$ of lepton flavors facing recent experimental data of neutrino oscillations. The mass matrices of neutrinos and charged leptons are essentially given…
In multi-component scalar dark matter scenarios, a single $Z_N$ ($N\geq 4$) symmetry may account for the stability of different dark matter particles. Here we study the case where $N$ is even ($N=2n$) and two species, a complex scalar and a…
Matter and dark matter are unified under the framework of $SU(6)\to SU(5) \times U(1)_N$. A dark-matter candidate is possible, not because it is stable, but because it has a very long lifetime, in analogy to that of the proton in theories…
We consider a class of nonlinear ordinary differential equations of the second order with parameters. We establish conditions for perturbations of the coefficients of the equation under which the zero solution is asymptotically stable.…
From the observed results, we deduced that the mass of the neutrino is about 10^(-1) eV and the mass of the fourth stable elementary particle (delta) is about 10^(0) eV. While neutrino is related to electro-weak field, the fourth stable…
Neutron stars could contain a mixture of ordinary nuclear matter and dark matter, such that dark matter could influence observable properties of the star, such as its mass and radius. We study these dark matter admixed neutron stars for two…
In the context of the $\mathrm{SU(3)_c \otimes SU(3)_L \otimes U(1)_X \otimes U(1)_{N}}$ (3-3-1-1) extension of the standard model, we show how the spontaneous breaking of the gauge symmetry gives rise to a residual symmetry which accounts…
We study a Zee-Babu neutrino model in a non-holomorphic modular $A_4$ symmetry, and we construct a model so that there are minimum free parameters (two complex parameters). We find only the normal hierarchy is allowed. Moreover, the allowed…
The regime of dark matter (DM) freeze-in at stronger coupling interpolates between freeze-in and freeze-out. It relies on Boltzmann-suppressed dark matter production, implying that the Standard Model bath temperature never exceeds the dark…
We derive the renormalization group equations for the neutrino masses and mixing angles in explicit form and discuss the possible classes of their solutions. We identify fixed points in the equations for mixing angles, which can be reached…
A new idea for neutrino mass was proposed recently, where its smallness is not due to the seesaw mechanism, i.e. not inversely proportional to some large mass scale. It comes from a one-loop mechanism with dark matter in the loop consisting…
We present a unified model of dark matter and dark energy. The dark matter field is a modulus corresponding to a flat direction of supersymmetry, which couples, in a hybrid type potential, with the dark energy field. The latter is a light…
Stability of the zero solution plays an important role in the investigation of positive systems. In this note, we revisit the $\mu$-stability of positive nonlinear systems with unbounded time-varying delays. The system is modelled by…
A new understanding of the stability of self-interacting dark matter is pointed out, based on the simplest spontaneously broken Abelian $U(1)$ gauge model with one complex scalar and one Dirac fermion. The key is the imposition of dark…