Damping of Gravitational Waves in Matter Dominated Era

Jafar Khodagholizadeh (IPM)
Tuesday, 94/08/26 (November 17, 2015) 13:30

We derive an integro-differential equation for propagation of cosmological gravitation waves in matter dominated era whereas the traceless transverse tensor part of the anisotropic stress tensor is free streaming neutrinos and antineutrinos which has been traveling essentially without collisions since the temperature dropped below about $ 10^{10} (K) $. and then we compare the results with the radiation dominated case in both flat and closed spacetimes and investigate the effect of closed background on the amplitude of the gravitational waves.