Results 41 to 50 of about 60,199 (278)

Cosmological perturbations in Palatini formalism [PDF]

Journal of Cosmology and Astroparticle Physics, 2021
29 pages, Comments welcome!
Yamaguchi, Masahide, Kubota, Mio, Oda, Kinya, Shimada, Keigo   +3 more
openaire   +3 more sources

ONE-DIMENSIONAL SIMULATIONS OF INHOMOGENEITY GROWTH IN PRESSURELESS GRAVITATING MATTER

Odessa Astronomical Publications, 2013
We study a model of the inhomogene­ity growth in the Universe filled with a pressureless matter. The standard hydrodynamical equations for the cosmological perturbations in the comoving frame are treated taking into account all nonlinear terms.
V. I. Zhdanov, V. M. Sliusar
doaj   +1 more source

Cosmological Perturbations from Cosmic Strings [PDF]

, 1994
Some aspects of the theory of cosmological perturbations from cosmic strings and other topological defects are outlined, with particular reference to a simple example: a spatially flat CDM-dominated universe.
Albrecht, Albrecht, Austin, Bennett, Coulson, Hindmarsh, Kolb, M. Hindmarsh, Pen, Sakellariadou, Shellard, Smith, Veeraraghavan, Vilenkin, Weinberg, White   +15 more
core   +3 more sources

Renormalized cosmological perturbation theory

Physical Review D, 2006
We develop a new formalism to study nonlinear evolution in the growth of large-scale structure, by following the dynamics of gravitational clustering as it builds up in time. This approach is conveniently represented by Feynman diagrams constructed in terms of three objects: the initial conditions (e.g.
Crocce, M., Scoccimarro, R.
openaire   +2 more sources

Nonconservative unimodular gravity: a viable cosmological scenario?

European Physical Journal C: Particles and Fields, 2022
In this work we review the issue of imposing the conservation of the energy–momentum tensor as a necessary condition to recover the equivalence between the unimodular gravity and General Relativity (GR) equipped with a cosmological constant.
Júlio C. Fabris, Marcelo H. Alvarenga, Mahamadou Hamani-Daouda, Hermano Velten   +3 more
doaj   +1 more source

Cosmological Perturbations via Quantum Corrections in M-Theory

Universe, 2021
In the early universe, it is important to take into account the quantum effect of gravity to explain the feature of inflation. In this paper, we consider the M-theory effective action which consists of 11-dimensional supergravity and (Weyl)4 terms.
Kazuho Hiraga, Yoshifumi Hyakutake
doaj   +1 more source

On Brane World Cosmological Perturbations [PDF]

, 2002
We discuss the scalar cosmological perturbations in a 3-brane world with a 5D bulk. We first show explicitly how the effective perturbed Einstein's equations on the brane (involving the Weyl fluid) are encoded into Mukohyama's master equation.
A. Lue, A.G. Riess, B. Leong, C. Csaki, C. Deffayet, C. Deffayet, C. Deffayet, C. Deffayet, C. Deffayet, C. Gordon, C. van de Bruck, C. van de Bruck, Cédric Deffayet, D. Langlois, D. Langlois, D. Langlois, D. Wands, G. Dvali, G. Dvali, G.R. Dvali, G.R. Dvali, G.R. Dvali, G.W. Gibbons, H. Ishihara, H. Kodama, H. Kodama, H. van Dam, H.A. Bridgman, H.A. Bridgman, I. Antoniadis, J. Garriga, J. Khoury, J.M. Bardeen, J.M. Cline, J.P. Uzan, K. Koyama, K. Lanczos, L. Randall, M. Dorca, M. Porrati, N. Arkani-Hamed, N. Arkani-Hamed, N. Deruelle, N. Deruelle, N. Deruelle, N. Deruelle, N. Sago, N. Sen, P. Binetruy, P. Binetruy, P. Binetruy, P. Kraus, P.P. Avelino, R. Maartens, S. Mukohyama, S. Mukohyama, S. Mukohyama, S. Mukohyama, S. Mukohyama, S. Perlmutter, S.W. Hawking, T. Boehm, T. Shiromizu, U. Gen, V.F. Mukhanov, V.I. Zakharov, W. Israel, W. Israel, Y. Iwasaki   +68 more
core   +1 more source

Conserved cosmological perturbations [PDF]

Physical Review D, 2003
21 pages, latex with revtex, no ...
Lyth, David H., Wands, David
openaire   +4 more sources

Cosmological perturbations in generalised dark Lagrangians

Journal of High Energy Physics, 2018
We describe a new method to parameterise dark energy theories including massive gravity, elastic dark energy and tensor-metric theories. We first examine the existing framework which describes any second order Lagrangian which depends on the variation of
James Edholm, Jonathan Pearson
doaj   +1 more source

Non-linear stability of α′-corrected Friedmann equations

Journal of High Energy Physics, 2023
We study the non-linear stability of fixed-point solutions to the α′-exact equations from O(d, d) invariant cosmology, with and without matter perturbations.
Heliudson Bernardo, Jan Chojnacki, Vincent Comeau   +2 more
doaj   +1 more source