Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-06-16
Phys.Rev. D69 (2004) 023503
Astronomy and Astrophysics
Astrophysics
14 pages. The original version of this paper has been expanded to deal with perturbations of any wavelength. While for wavelen
Scientific paper
10.1103/PhysRevD.69.023503
An analytic formula is given for the traceless transverse part of the anisotropic stress tensor due to free streaming neutrinos, and used to derive an integro-differential equation for the propagation of cosmological gravitational waves. The solution shows that anisotropic stress reduces the squared amplitude by 35.6 % for wavelengths that enter the horizon during the radiation-dominated phase, independent of any cosmological parameters. This decreases the tensor temperature and polarization correlation functions for these wavelengths by the same amount. The effect is less for wavelengths that enter the horizon at later times. At the longest wavelengths the decrease in the tensor correlation functions due to neutrino free streaming ranges from 10.7% for $\Omega_Mh^2=0.1$ to 9.0% for $\Omega_Mh^2=0.15$. An Appendix gives a general proof that tensor as well as scalar modes satisfy a conservation law for perturbations outside the horizon, even when the anisotropic stress tensor is not negligible.
No associations
LandOfFree
Damping of Tensor Modes in Cosmology 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 Damping of Tensor Modes in Cosmology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Damping of Tensor Modes in Cosmology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-674655