21 research outputs found
Noncommutative effective LQC: A (pre-)inflationary dynamics investigation
We conduct a (pre-)inflationary dynamics study within the framework of a
simple noncommutative extension of effective loop quantum cosmology -- put
forward recently by the authors -- which preserves its key features (in
particular, the quantum bounce is maintained). A thorough investigation shows
that the (pre-)inflationary scenario associated to the chaotic quadratic
potential is in the overall the same as the one featured in standard loop
quantum cosmology (which reinforces the conclusion reached by the authors in a
preliminary analysis). Hence, this (pre-)inflationary scenario does not easily
distinguish between standard loop quantum cosmology and the aforementioned
noncommutative scheme. It is argued that a particular tuning of the
noncommutativity parameter could accommodate for subtle effects at the level of
primordial perturbations (the hybrid quantization framework being a tentative
route of analysis).Comment: 22 pages, 18 figures, 1 tabl
Quintom fields from chiral anisotropic cosmology
In this paper we present an analysis of a chiral anisotropic cosmological
scenario from the perspective of quintom fields. In this setup quintessence and
phantom fields interact in a non-standard (chiral) way within an anisotropic
Bianchi type I background. We present our examination from two fronts:
classical and quantum approaches. In the classical program we find analytical
solutions given by a particular choice of the emerged relevant parameters.
Remarkably, we present an explanation of the ''big-bang'' singularity by means
of a ''big-bounce''. Moreover, isotropization is in fact reached as the time
evolves. On the quantum counterpart the Wheeler-DeWitt equation is analytically
solved for various instances given by the same parameter space from the
classical study, and we also include the factor ordering . Having
solutions in this scheme we compute the probability density, which is in effect
damped as the volume function and the scalar fields evolve; and it also tends
towards a flat FLRW framework when the factor ordering constant .
This result might indicate that for a fixed set of parameters, the anisotropies
quantum-mechanically vanish for very small values of the parameter .
Finally, classical and quantum solutions reduce to their flat FLRW counterparts
when the anisotropies vanish.Comment: 14 pages, 4 figure