1997/05/21 by Sabino Matarrese, Matarrese, Sabino, Silvia Mollerach +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #astro-ph #gr-qc
paper · pdf · doi:10.48550/arxiv.astro-ph/9705168
14 pages, in Latex using ere96.sty (included). Invited talk at the Spanish Relativity Meeting (ERE-96), Valencia 1996, J.A. Miralles, J.A. Morales & D. Saez eds
arxiv created 1997/05/21 · arxiv updated 2009/11/30
The cosmological stochastic gravitational-wave background produced by the mildly non-linear evolution of density fluctuations is analyzed, in the frame of an Einstein-de Sitter model, by means of a fully relativistic perturbation expansion up to second order. The form of these gravitational-instability-induced gravitational waves is gauge-dependent. In the synchronous gauge, where the second-order expansion is most easily carried out, the transverse and traceless tensor modes which are produced also contain a Newtonian and post-Newtonian piece, whose interpretation as gravitational waves is non-trivial. A more direct physical understanding of this background is obtained in the so-called Poisson gauge, where it is seen to consist of a constant term plus an oscillating piece whose amplitude decays inside the Hubble radius.