Viscous cosmologies

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Viscous Cosmologies with Extra Dimensions

We present an analysis of a n-dimensional vacuum Einstein field equations in which 4-dimensional space-time with is described by a Friedmann Robertson-Walker (FRW) metric and that of the extra dimensions by a Kasner type Euclidean metric. The field equations are interpreted as four dimensional Einstein equations with effective matter properties. We obtain solutions for the cases when the effect...

متن کامل

Scalar Field Cosmologies with Viscous Fluid

We investigate cosmological models with a free scalar field and a viscous fluid. We find exact solutions for a linear and nonlinear viscosity pressure. Both yield singular and bouncing solutions. In the first regime, a de Sitter stage is asymptotically stable, while in the second case we find power-law evolutions for vanishing cosmological constant. PACS 04.20 Jb, 04.40 Nr, 98.80 Hw

متن کامل

Viscous Cosmologies with Variable G and Λ in R Gravity

We study evolution of a flat Friedmann-Robertson Walker universe filled with a bulk viscous cosmological fluid in a higher derivative theory of gravity in the presence of time varying gravitational and cosmological constant. Cosmological models admitting both power-law and exponential expansions are explored here in the presence of imperfect fluid described by full Israel and Stewart theory. We...

متن کامل

A Brief Review of the Singularities in 4d and 5d Viscous Cosmologies near the Future Singularity

Analytic properties of physical quantities in the cosmic fluid such as energy density ρ(t) and Hubble parameter H(t) are investigated near the future singularity (Big Rip). Both 4D and 5D cosmologies are considered (the Randall-Sundrum II model in the 5D case), and the fluid is assumed to possess a bulk viscosity ζ. We consider both Einstein gravity and modified gravity, where in the latter cas...

متن کامل

Noncommutative Mixmaster Cosmologies

In this paper we investigate a variant of the classical mixmaster universe model of anisotropic cosmology, where the spatial sections are noncommutative 3-tori. We consider ways in which the discrete dynamical system describing the mixmaster dynamics can be extended to act on the noncommutative torus moduli, and how the resulting dynamics differs from the classical one, for example, in the appe...

متن کامل

ذخیره 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: Classical and Quantum Gravity

سال: 2019

ISSN: 0264-9381,1361-6382

DOI: 10.1088/1361-6382/ab45bb