Results 31 to 40 of about 74,681 (258)

Newtonian versus relativistic cosmology

, 2012
We show how the relativistic matter and velocity power spectra behave in different gauges. We construct a new gauge where both spectra coincide with Newtonian theory on all scales.
Flender, Samuel F., Schwarz, Dominik J.
core   +1 more source

Off-diagonal cosmological solutions in emergent gravity theories and Grigory Perelman entropy for geometric flows

European Physical Journal C: Particles and Fields, 2021
We develop an approach to the theory of relativistic geometric flows and emergent gravity defined by entropy functionals and related statistical thermodynamics models. Nonholonomic deformations of G.
Sergiu I. Vacaru, Elşen Veli Veliev, Laurenţiu Bubuianu   +2 more
doaj   +1 more source

Conformal Symmetries of the Strumia–Tetradis’ Metric

Physical Sciences Forum, 2023
In a recent paper, a new conformally flat metric was introduced, describing an expanding scalar field in a spherically symmetric geometry. The spacetime can be interpreted as a Schwarzschild-like model with an apparent horizon surrounding the curvature ...
Pantelis S. Apostolopoulos, Christos Tsipogiannis   +1 more
doaj   +1 more source

Lagrangian description of the fluid flow with vorticity in the relativistic cosmology

, 1999
We develop the Lagrangian perturbation theory in the general relativistic cosmology, which enables us to take into account the vortical effect of the dust matter.
D.S. Salopek, H. Friedrich, H. Kodama, H. Russ, Hideki Asada, J. Ehlers, J. Ehlers, J. Glanz, J. Parry, J.M. Bardeen, K. Tomita, K. Tomita, K. Tomita, K.M. Croudace, M. Kasai, M. Morita, M. Sasaki, M. Shibata, M. Takada, Masumi Kasai, P.J.E. Peebles, S. Matarrese, S. Matarrese, S. Matarrese, S. Weinberg, T. Buchert, T. Buchert, T. Buchert, T. Buchert, T. Futamase, T. Futamase, Y.B. Zel’dovich   +31 more
core   +1 more source

Regional averaging and scaling in relativistic cosmology [PDF]

, 2002
Averaged inhomogeneous cosmologies lie at the forefront of interest, since cosmological parameters like the rate of expansion or the mass density are to be considered as volume-averaged quantities and only these can be compared with observations.
Buchert, Thomas, Carfora, Mauro
core   +3 more sources

Entropic force and its cosmological implications

, 2011
We investigate a possibility of realizing the entropic force into the cosmology. A main issue is how the holographic screen is implemented in the Newtonian cosmology.
A. Sheykhi, C. Gao, J.C. Hwang, J.D. Bekenstein, J.M. Bardeen, L. Susskind, L. Susskind, M. Li, R. Bousso, R.G. Cai, R.G. Cai, S. Rasanen, S.W. Hawking, T. Jacobson, T. Padmanabhan, T. Rainsford, Y. Tian, Y.S. Myung, Y.S. Myung, Yun Soo Myung   +19 more
core   +1 more source

Braneworlds and Quantum States of Relativistic Shells [PDF]

, 2007
We review some applications of relativistic shells that are relevant in the context of quantum gravity/quantum cosmology. Using a recently developed approach, the stationary states of this general relativistic system can be determined in the ...
Ansoldi, Stefano
core   +2 more sources

Relations between Newtonian and Relativistic Cosmology

Universe
We start with the cosmic Friedmann equations, where we adopt a novel perspective rooted in a Lagrangian formulation, grounded in Newtonian mechanics and the first law of thermodynamics. Our investigation operates under the assumption that the universe is
Jaume de Haro
doaj   +1 more source

Topological acceleration in relativistic cosmology

, 2012
Heuristic approaches in cosmology bypass more difficult calculations that would more strictly agree with the standard Einstein equation. These give us the well-known Friedmann-Lemaitre-Robertson-Walker (FLRW) models, and, more recently, the feedback ...
Roukema, Boudewijn F.
core   +1 more source

General Relativistic Self-Similar Solutions in Cosmology [PDF]

, 2006
We present general relativistic solutions for self-similar spherical perturbations in an expanding cosmological background of cold pressure-less gas. We focus on solutions having shock discontinuities propagating in the surrounding cold gas. The pressure,
Nusser, Adi
core   +2 more sources