Results 1 to 10 of about 193,127 (291)

Scalar-Tensor Cosmological Models [PDF]

Physical Review D, 1995
We analyze the qualitative behaviors of scalar-tensor cosmologies with an arbitrary monotonic $\omega(\Phi)$ function. In particular, we are interested on scalar-tensor theories distinguishable at early epochs from General Relativity (GR) but leading to ...
A. A. Coley, A. Burd, A. Meisels, A. R. Liddle, A. R. Liddle, A. Serna, A. Serna, A. Serna, A. Serna, B. M. Barker, C. Brans, C. M. Will, D. La, D. La, D. Lorentz Petzold, E. Vayonakis, E. W. Kolb, E. W. Weinberg, F. S. Accetta, G. S. Greenstein, G. Schmidt, G. Yepes, J. D. Barrow, J. D. Barrow, J. D. Barrow, J. D. Bekenstein, J. D. Bekenstein, J. D. Bekenstein, J. Garcí a Bellido, J. M. Alimi, J. P. Mimoso, K. Nordtvedt, M. M. Green, P. G. Bergmann, P. J. Steinhardt, P. Jordan, P. S. Wesson, P. S. Wesson, R. Holman, R. Holman, R. Holman, R. V. Wagoner, S. J. Kolitch, S. Weinberg, T. Damour, Y. M. Cho   +45 more
core   +5 more sources

Quantum Cosmological Models [PDF]

Classical and Quantum Gravity, 2004
We contrast the initial condition requirements of various contemporary cosmological models, including inflationary and bouncing cosmologies. Various proposals such as Hartle-Hawking's no boundary, or Tunnelling boundary conditions are assessed on grounds
Coule, D. H.
core   +4 more sources

Stability Properties of Geometrothermodynamic Cosmological Models [PDF]

Entropy, 2023
We consider a particular isotropic and homogeneous cosmological model, in which the equation of state is obtained from a thermodynamic fundamental equation by using the formalism of geometrothermodynamics (GTD).
Nurzada Beissen, Medeu Abishev, Manas Khassanov, Temirbolat Aitassov, Sagira Mamatova, Saken Toktarbay   +5 more
doaj   +2 more sources

Metaphysics of cosmological models

HTS Teologiese Studies/Theological Studies, 2023
This article aims to address the metaphysical dimension of cosmological models, be they mythological, philosophical, religious or modern scientific, using multidisciplinary and transdisciplinary methodology.
Vasile Chira
doaj   +1 more source

Little Ado about Everything: ηCDM, a Cosmological Model with Fluctuation-driven Acceleration at Late Times

The Astrophysical Journal, 2023
We propose a model of the Universe (dubbed η CDM) featuring a controlled stochastic evolution of the cosmological quantities that is meant to render the effects of small deviations from homogeneity/isotropy on scales of 30–50 h ^−1 Mpc at late cosmic ...
Andrea Lapi, Lumen Boco, Marcos M. Cueli, Balakrishna S. Haridasu, Tommaso Ronconi, Carlo Baccigalupi, Luigi Danese   +6 more
doaj   +1 more source

Spherically Symmetric Exact Vacuum Solutions in Einstein-Aether Theory

Universe, 2021
We study spherically symmetric spacetimes in Einstein-aether theory in three different coordinate systems, the isotropic, Painlevè-Gullstrand, and Schwarzschild coordinates, in which the aether is always comoving, and present both time-dependent and time-
Jacob Oost, Shinji Mukohyama, Anzhong Wang   +2 more
doaj   +1 more source

Stability Of Cosmological Models [PDF]

Symposium - International Astronomical Union, 1995
The stability problem in cosmology is studied using the equations of geodesic deviation. General conditions for stability are obtained. The method is applied to a number of cosmological models, resulting from different field theories. The results are compared with those obtained from FRW -models.
Wanas, M. I., Bakry, M. A.
openaire   +2 more sources

Cosmological Constant from Boundary Condition and Its Implications beyond the Standard Model

Universe, 2023
Standard cosmology has long been plagued by a number of persistent problems. The origin of the apparent acceleration of the cosmic expansion remains enigmatic.
Jan O. Stenflo
doaj   +1 more source

Errant Man: The Importance of Cosmological Models in Culture [PDF]

Философия и космология, 2019
The author considers the meanings of the term “errant man” in the paper. The birth of man is his abandonment in being and wandering in it. It is important that wandering in being have direction, the source that drives man, forms the authenticity ...
Iryna Dobroskok
doaj   +1 more source

Polynomial Affine Model of Gravity in Three-Dimensions

Universe, 2022
In this work, we explore a three-dimensional formulation of the polynomial affine model of gravity, which is a model that extends general relativity by relaxing the equivalence principle through the exclusion of the metric from the set of fundamental ...
Oscar Castillo-Felisola, Bastian Grez, Oscar Orellana, Jose Perdiguero, Francisca Ramirez, Aureliano Skirzewski, Alfonso R. Zerwekh   +6 more
doaj   +1 more source