Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-05-20
Phys.Lett.B677:235-238, 2009; Phys.Lett.B677:235-238,2009
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
5 pages, 3 figures and 1 table, Published version
Scientific paper
10.1016/j.physletb.2009.05.046
We discuss a method to constrain the fraction density $f$ of the relativistic gas in the radiation dominant stage, by their impacts on a relic gravitational waves and the cosmic microwave background (CMB) $B$ polarization power spectrum. We find that the uncertainty of $f$ strongly depends on the noise power spectra of the CMB experiments and the amplitude of the gravitational waves. Taking into account of the CMBPol instrumental noises, an uncertainty $\Delta f=0.046$ is obtained for the model with tensor-to scalar ratio $r=0.1$. For an ideal experiment with only the reduced cosmic lensing as the contamination of $B$-polarization, $\Delta f=0.008$ is obtained for the model with $r=0.1$. So the precise observation of the CMB $B$-polarization provides a great opportunity to study the relativistic components in the early Universe.
Xia Tianyang
Zhang Yang
Zhao Wen
No associations
LandOfFree
New method to constrain the relativistic free-streaming gas in the Universe 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 New method to constrain the relativistic free-streaming gas in the Universe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New method to constrain the relativistic free-streaming gas in the Universe will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-242215