Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation

Details Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation

2006-06-29

arxiv.org/abs/astro-ph/0606731v3

Phys.Lett.B642:13-17,2006

Astronomy and Astrophysics

Astrophysics

10 pages, 2 figures, final PLB accepted version

Scientific paper

10.1016/j.physletb.2006.09.013

We discuss certain issues related to the limitations of density parameters for a ``radiation''-like contribution to the Friedmann equation using kinematical or geometrical measurements. We analyse the observational constraint of a negative $(1+z)^4$-type contribution in cosmological models. We argue that it is not possible to determine the energy densities of individual components of matter scaling like radiation from astronomical observations. We find three different interpretations of the presence of the radiation term: 1) the FRW universe filled with a massless scalar field in a quantum regime (the Casimir effect), 2) the Friedmann-Robertson-Walker (FRW) model in the Randall Sundrum scenario with dark radiation, 3) the cosmological model with global rotation. From supernovae type Ia (SNIa) data, Fanaroff-Riley type IIb (FRIIb) radio galaxy (RG) data, baryon oscillation peak and cosmic microwave background radiation (CMBR) observations we obtain bounds for the negative radiation-like term. A small negative contribution of dark radiation can reconcile the tension in nucleosynthesis and remove also the disagreement between $H_0$ values obtained from both SNIa and the Wilkinson Microwave Anisotropy Probe (WMAP) satellite data.

Affiliated with

Also associated with

No associations

Rating

Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Towards observational constraints on negative (1+z)^4 type contribution in the Friedmann equation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-597631