منابع مشابه
Analytic solutions for the Λ-FRW Model
The high precision attained by cosmological data in the last few years has increased the interest in exact solutions. Analytic expressions for solutions in the Standard Model are presented here for all combinations of Λ = 0 , Λ 6= 0, κ = 0 and κ 6= 0, in the presence and absence of radiation and nonrelativistic matter. The most complete case (here called the ΛγCDM Model) has Λ 6= 0, κ 6= 0, and...
متن کاملClassical solutions from quantum regime for barotropic FRW model
It is a general belief that the existence of an initial singularity can be remove through the employment of a quantum theory of gravity. However, there is no consistent theory of gravity until now, and in this sense the problem of the initial singularity remains of actuality. It is well known that is possible to construct a quantum model for the universe as a whole, through the Wheeler-DeWitt (...
متن کاملthe use of appropriate madm model for ranking the vendors of mci equipments using fuzzy approach
abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...
15 صفحه اولSome Frw Models with Variable G and Λ
We consider several models with metrics type FRW, with k = 0 and with a generic equation of state, p = ωρ, furthermore, we take into account the conservation principle of the energy-momentum tensor, div(Tij) = 0, but with G and Λ variable. We find trivially, a set of solutions through dimensional analysis. We stand out that, G ∝ t, i.e. its behaviour depends on the state equation and Λ ∝ t in a...
متن کامل0 FRW Cosmological Solutions in M - theory
We present the canonical and quantum cosmological investigation of a four-dimensional, spatially flat, Friedmann-Robertson-Walker (FRW) model that is derived from the bosonic Neveu-Schwarz/Neveu-Schwarz sector of the low-energy M-theory effective action. We discuss in detail the phase space of the classical theory. We find the quantum solutions of the model and obtain the positive norm Hilbert ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Foundations of Physics
سال: 2006
ISSN: 0015-9018,1572-9516
DOI: 10.1007/s10701-006-9076-6