Anisotropic cosmologies containing isotropic background radiation
نویسندگان
چکیده
منابع مشابه
Anisotropic universes with isotropic cosmic microwave background radiation
We show the existence of spatially homogeneous but anisotropic cosmological models whose cosmic microwave background temperature is exactly isotropic at one instant of time but whose rate of expansion is highly anisotropic. The existence of these models shows that the observation of a highly isotropic cosmic microwave background temperature cannot alone be used to infer that the universe is clo...
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We study isotropic and anisotropic (Bianchi I) cosmologies in Palatini f(R) and f(R,RμνR μν) theories of gravity and consider the existence of non-singular bouncing solutions in the early universe. We find that all f(R) models with isotropic bouncing solutions develop shear singularities in the anisotropic case. On the contrary, the simple quadratic model R+ aR/RP +RμνR /RP exhibits regular bou...
متن کاملLETTER TO THE EDITOR Anisotropic universes with isotropic cosmic microwave background radiation
We show the existence of spatially homogeneous but anisotropic cosmological models whose cosmic microwave background temperature is exactly isotropic at one instant of time but whose rate of expansion is highly anisotropic. The existence of these models shows that the observation of a highly isotropic cosmic microwave background temperature cannot alone be used to infer that the universe is clo...
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Anisotropic cosmological spacetimes are constructed from spherically symmetric solutions to Einstein’s equations coupled to nonlinear electrodynamics and a positive cosmological constant. This is accomplished by finding solutions in which the roles of r and t are interchanged for all r > 0 (i.e. r becomes timelike and t becomes spacelike). Constant time hypersurfaces have topology R × S and in ...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2001
ISSN: 0556-2821,1089-4918
DOI: 10.1103/physrevd.64.083502