Deceleration parameter in tilted Friedmann universes
نویسندگان
چکیده
منابع مشابه
Light deflection in perturbed Friedmann universes.
In this letter a new formula for light deflection is derived using only physically observable concepts. The general result is specialized to cosmological perturbation theory and expressed in terms of gauge–invariant perturbation variables. The resulting scalar, vector and tensor equations are supplemented by simple examples for illustration. The gravity wave example may be of more than academic...
متن کاملAngular Diameter Distances in Clumpy Friedmann Universes
Solving null-geodesic equations, behavior of angular diameter distances is studied in inhomogeneous cosmological models, which are given by performing N-body simulations with the CDM spectrum. The distances depend on the separation angle θ of ray pairs, the mass m and the radius rs of particles consisting of galaxies and dark matter balls, and cosmological model parameters. The calculated dista...
متن کاملOne - parameter family of closed , radiation - filled Friedmann - Robertson - Walker “ quantum ” universes
Using as an illustrative example the p=1 operator-ordered Wheeler-DeWitt equation for a closed, radiation-filled Friedmann-Robertson-Walker universe, we introduce and discuss the supersymmetric double Darboux method in quantum cosmology. A one-parameter family of " quantum " universes and the corresponding " wavefunctions of the universe " for this case are presented. Many interesting results h...
متن کاملInhomogeneous dusty Universes and their deceleration
Exact results stemming directly from Einstein equations imply that inhomogeneous Universes endowed with vanishing pressure density can only decelerate, unless the energy density of the Universe becomes negative. Recent proposals seem to argue that inhomogeneous (but isotropic) space-times, filled only with incoherent matter, may turn into accelerated Universes for sufficiently late times. To sc...
متن کاملThe Future of Tilted Bianchi Universes
An asymptotic stability analysis of spatially homogeneous models of Bianchi type containing tilted perfect fluids is performed. Using the known attractors for the non-tilted Bianchi type universes, we check whether they are stable against perturbations with respect to tilted perfect fluids. We perform the analysis for all Bianchi class B models and the Bianchi type V I0 model. In particular, we...
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: Physical Review D
سال: 2015
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.92.043515