The perturbation of gravitational waves in plasma in the FRW space-time

摘要

In this paper we study the perturbation of gravitational waves in plasma, using the relativistic hydro-magnetic equation in the so-called Cowling approximation considering a Friedman-Robertson-Walker (FRW) cosmological model. It has been assumed the gravitational field and the weak magnetic field do not break the homogeneity and isotropy of the considered FRW space time. Applying the formalism proposed for Zel'dovich and Novikov (The structure and evolution of the universe, Volume II, 1983), Brandenburg et al. (Phys. Rev. D 54: 1291, 1996) and Weinberg (Gravitation and Cosmology, 1972). We verify that density fluctuation may be obtained.