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arXiv · 1608.01472

Tensor Modes Damping in Matter and Vacuum Dominated Era

Jafar Khodagholizadeh·Amir H. Abbassi·Ali A. Asgari
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Abstract

The present paper has developed an integro-differential equation to propagate cosmological gravitation waves in matter-dominated era in accounting for the presence of free streaming neutrinos as a traceless transverse tensor part of the anisotropic stress tensor. Its focus is on short and long wavelengths of GWs that enter the horizon in matter-dominated era. Results show that the anisotropic stress reduces the squared amplitude by $ 0.03\%$ for wavelengths, entering the horizon during matter-dominated phase. This reduction is less for those wavelengths that enter the horizon at $ \Lambda $ dominated era in flat spacetime. All of the calculations have been done in closed spacetime and the results have been compared with the radiation-dominated case for both flat and closed spacetimes. Finally the paper investigates the effect of closed background on the amplitude of the gravitational waves.

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Jafar Khodagholizadeh, Amir H. Abbassi, Ali A. Asgari. 2016-08-04. Tensor Modes Damping in Matter and Vacuum Dominated Era. https://arxiv.org/abs/1608.01472

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