Shear dynamics in Bianchi I cosmologies with R-gravity
نویسنده
چکیده
We give the equations governing the shear evolution in Bianchi spacetimes for general f(R)-theories of gravity. We consider the case of R-gravity and perform a detailed analysis of the dynamics in Bianchi I cosmologies which exhibit local rotational symmetry. We find exact solutions and study their behaviour and stability in terms of the values of the parameter n. In particular, we found a set of cosmic histories in which the universe is initially isotropic, then develops shear anisotropies which will dissipate at late times to a constant value σ0. PACS numbers: 98.80.JK, 04.50.+h, 05.45.-a
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تاریخ انتشار 2006