The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

9 pages, 6 figures, Submitted to MNRAS. High resolution colour pictures can be obtained on request from the authors

Scientific paper

10.1046/j.1365-8711.2002.05570.x

Recent estimates of cosmological parameters derived from Cosmic Microwave Background (CMB) anisotropies are based on the assumption that we know the precise amount of energy density in relativistic particles in the universe, $\omega_{rel}$, at all times. There are, however, many possible mechanisms that can undermine this assumption. In this paper we investigate the effect that removing this assumption has on the determination of the various cosmological parameters. We obtain fairly general bounds on the redshift of equality, $z_{eq}= \omega_{m}/\omega_{rel}=3100_{-400}^{+600}$. We show that $\omega_{rel}$ is nearly degenerate with the amount of energy in matter, $\omega_m$, and that its inclusion in CMB parameter estimation also affects the present constraints on other parameters such as the curvature or the scalar spectral index of primordial fluctuations. This degeneracy has the effect of limiting the precision of parameter estimation from the MAP satellite, but it can be broken by measurements on smaller scales such as those provided by the Planck satellite mission.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies 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 The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Impact of an Extra Background of Relativistic Particles on the Cosmological Parameters derived from Microwave Background Anisotropies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-12913

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.