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Register a new userAn unified cosmological evolution driven by a mass dimension one fermionic field
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An unified cosmological model for an Universe filled with a mass dimension one (MDO) fermionic field plus the standard matter fields is considered. After a primordial quantum fluctuation the field slowly rolls down to the bottom of a symmetry breaking potential, driving the Universe to an inflationary regime that increases the scale factor for about 71 e-folds. After the end of inflation, the field starts to oscillate and can transfer its energy to the standard model particles through a reheating mechanism. Such a process is briefly discussed in terms of the admissible couplings of the MDO field with the electromagnetic and Higgs fields. We show that even if the field loses all its kinetic energy during reheating, it can evolve as dark matter due a gravitational coupling (of spinorial origin) with baryonic matter. Since the field acquires a constant value at the bottom of the potential, a non-null, although tiny, mass term acts as a dark energy component nowadays. Therefore, we conclude that MDO fermionic field is a good candidate to drive the whole evolution of the Universe, in such a way that the inflationary field, dark matter and dark energy are described by different manifestations of a single field.
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This paper study the evolution of the universe filled with a neutral mass dimension one fermionic field, sometimes called Elko. The numerical analysis of the coupled system of equations furnish a scale factor growth and energy density evolution that correctly reproduces the inflationary phase of the universe. After that, supposing a mechanism of energy transference to ordinary matter, the initial conditions generated after inflation drives the radiation dominated phase and also the subsequent dark matter evolution, since the Elko field is a good dark matter candidate. The energy density of the field at the end of inflation, at the end of radiation phase and for present time are in agreement to the standard model estimates. The analysis was performed with a potential containing a quadratic mass term plus a quartic self-interaction term, which follows naturally from the theory of mass dimension one fermions. It is interesting to notice that inflation occurs when the field makes a kind of transition around the Planck mass scale. The number of e-foldings during inflation was found to be strongly dependent on the initial conditions of the Elko field, as occurs in chaotic inflationary models. An upper mass limit for Elko field has been obtained as $m<10^9$GeV. A possible interpretation of both inflationary phase and recent cosmic acceleration as a consequence of a kind of Pauli exclusion principle is presented at the end.
In this paper we proceed into the next step of formalization of a consistent dual theory for mass dimension one spinors. This task is developed approaching the two different and complementary aspects of such duals, clarifying its algebraic structure and the so called $tau-$deformation. The former regards the mathematical equivalence of the recent proposed Lorentz preserving dual with the duals of algebraic spinors, from Clifford algebras, showing the consistency and generality of the new dual. Moreover, by revealing its automorphism structure, the hole of the $tau-$deformation and contrasting the action group orbits with other Lorentz breaking scenarios, we argue that the new mass dimension one dual theory is placed over solid and consistent basis.
We study the dynamic collapse driven by a scalar field, when a relativistic observer falls co-moving with the collapse and cross the horizon of a Schwarzschild black-hole (BH), at $t=t_0$. During the collapse the scale of time is considered as variable. Back-reaction effects and gravitational waves produced during the exponential collapse are studied. We demonstrate that back-reaction effects act as the source of gravitational waves emitted during the collapse, and wavelengths of gravitational waves (GW) are in the range: $lambda ll r_sequiv {e^{-2h_0t_0}over 2 h_0}$, that is, smaller than the Schwarzschild radius. We demonstrate that during all the collapse the global topology of the space-time remains hyperbolic when the observer cross the horizon.
In this work we use momentum-space techniques to evaluate the propagator $G(x,x^{prime})$ for a spin $1/2$ mass dimension one spinor field on a curved Friedmann-Robertson-Walker spacetime. As a consequence, we built the one-loop correction to the effective lagrangian in the coincidence limit. Going further we compute the effective lagrangian in the finite temperature regime. We arrive at interesting cosmological consequences, as time-dependent cosmological `constant, fully explaining the functional form of previous cosmological models.
We study spherically symmetric solutions with a scalar field in the shift-symmetric subclass of the Horndeski theory. Constructing an effective energy-momentum tensor of the scalar field based on the two-fluid model, we decompose the scalar field into two components: dark matter and dark energy.We find the dark-matter fluid is pressure-less, and its distribution of energy density obeys the inverse-square law. We show the scalar field dark matter can explain the galaxy rotation curve and discuss the time evolution of the dark matter in the cosmic background.
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