Testing and selection of cosmological models with (1+z)^{6} corrections
Abstract
In the paper we check whether the contribution of ()(1+z)^{6} type in the Friedmann equation can be tested. We consider some astronomical tests to constrain the density parameters in such models. We describe different interpretations of such an additional term: geometric effects of loop quantum cosmology, effects of braneworld cosmological models, nonstandard cosmological models in metricaffine gravity, and models with spinning fluid. Kinematical (or geometrical) tests based on null geodesics are insufficient to separate individual matter components when they behave like perfect fluid and scale in the same way. Still, it is possible to measure their overall effect. We use recent measurements of the coordinate distances from the FanaroffRiley type IIb radio galaxy data, supernovae type Ia data, baryon oscillation peak and cosmic microwave background radiation observations to obtain stronger bounds for the contribution of the type considered. We demonstrate that, while ρ^{2} corrections are very small, they can be tested by astronomical observations—at least in principle. Bayesian criteria of model selection (the Bayesian factor, AIC, and BIC) are used to check if additional parameters are detectable in the present epoch. As it turns out, the ΛCDM model is favored over the bouncing model driven by loop quantum effects. Or, in other words, the bounds obtained from cosmography are very weak, and from the point of view of the present data this model is indistinguishable from the ΛCDM one.
 Publication:

Physical Review D
 Pub Date:
 February 2008
 DOI:
 10.1103/PhysRevD.77.043530
 arXiv:
 arXiv:0706.0283
 Bibcode:
 2008PhRvD..77d3530S
 Keywords:

 98.80.Jk;
 04.20.q;
 Mathematical and relativistic aspects of cosmology;
 Classical general relativity;
 General Relativity and Quantum Cosmology
 EPrint:
 19 pages, 1 figure. Version 2 generally revised and accepted for publication