Cosmological particle creation in the presence of Lorentz violation

Abstract

In recent years, the effects of Lorentz symmetry breaking in cosmology has attracted considerable amount of attention. In cosmological context several topics can be affected by Lorentz violation,e.g., inflationary scenario, CMB, dark energy problem and barryogenesis. In this paper we consider the cosmological particle creation due to Lorentz violation (LV). We consider an exactly solvable model for finding the spectral properties of particle creation in an expanding space-time exhibiting Lorentz violation. In this model we calculate the spectrum and its variations with respect to the rate and the amount of space-time expansion.

Optimal estimation of parameters for scalar field in an expanding spacetime exhibiting Lorentz invariance violation

“…It is worth noting that the behavior of quantum entanglement for a massless scalar field due to LIV during the evolution of expanding spacetime shown in Ref. [30], is similar with the behavior of QFI with respect to α 2 in our paper, which represents that the precision of expansion volume estimation will be enhanced by the increment of quantum entanglement.…”

“…It is shown that the QFI firstly increases and then starts to decrease by increasing the value of k, which means that the highest precision in the expansion volume estimating can be obtained at a specific momentum mode. This behavior of QFI is in analogy with the behavior of quantum entanglement for a massless scalar field in the presence of LIV on a two-dimensional asymptotically flat RW expanding spacetime [30], which indicates that the precision of expansion volume estimation will be improved by increasing of quantum entanglement. Moreover, as the expansion rate, ρ, grows, the QFI increases accordingly.…”

“…As considered in the Refs. [30,31], the generalized Lagrangian for the cosmological spacetime in the presence of LIV can be written as…”

Particle creation from vacuum by Lorentz violation

“…In this case for smaller value of α 2 0 the plot falls and for α 2 0 → 0 it coincides to N k = 0 for all k's, as one expected. We have studied a toy model to describe the effects of Lorentz violation in particle creation subject [17] in presence of a time dependent deformed dispersion relation. In this paper, we have shown that the existence of Lorentz violation in very early times' vacuum can result in the existence of particles but in the absence of any Lorentz violation.…”

Parameter estimation for a Lorentz invariance violation

“…As examples of such models we can mention the Double Special Relativity Theory [18][19][20][21], the Extra-Dimensional Theories [22], the Horava-Lifshitz Theory [24][25][26] and the Theories with Non-Commutative Geometries [26][27][28]. Another path pursued in recent research is the possibility of particle creation as well as entropy generation due to Lorentz invariance violation in the course of cosmological evolution [29][30][31]. In this viewpoint, the existence of particles and the entropy production can be interpreted as an evidence for quantum gravity effects in the early universe.…”