The Newtonian gravitational constant: Modern status of measurement and the new CODATA valuePleiades Publishing Ltd - Tập 18 - Trang 216-224 - 2012
V. Milyukov, Shu-hua Fan
Measurements of G, the Newtonian constant of gravitation, in laboratory experiments have a more than two hundred years’ history. Although the accuracy of the best modern experimental measurements of G reaches 15–40 ppm, the scatter of the measured values is large enough, and the knowledge of the absolute value of G is still rather poor. The results of the G measurements which were used for CODATA ...... hiện toàn bộ
Interaction of chiral fields of the dark sector with cold dark matterPleiades Publishing Ltd - Tập 18 - Trang 262-269 - 2012
R. R. Abbyazov, S. V. Chervon
We study models containing matter in the form of dust and the fields of a two-component nonlinear sigma model describing dark energy. We consider the background and perturbation equations for the suggested models and compare them with the ΛCDM model.
A Cosmological Scenario with RotationPleiades Publishing Ltd - Tập 25 - Trang 362-365 - 2019
O. V. Sandakova, D. M. Yanishevsky, V. F. Panov
A Bianchi type IX cosmological model with expansion and rotation has been constructed in the framework of general relativity. The model comprises the Friedmannian stages of the Universe evolution including the subsequent transition to accelerated exponential expansion observed nowadays. The gravitational field sources of the model are ultrarelativistic matter, dust and a comoving anisotropic rotat...... hiện toàn bộ
Conformally and gauge invariant spin-2 field equationsPleiades Publishing Ltd - Tập 19 - Trang 163-170 - 2013
C. S. O. Mayor, G. Otálora, J. G. Pereira
Using an approach based on the Casimir operators of the de Sitter group, conformally invariant equations for a fundamental spin-2 field are obtained, and their consistency is discussed. It is shown that only when the spin-2 field is interpreted as a 1-form assuming values in the Lie algebra of the translation group, rather than a symmetric second-rank tensor, the field equation is both conformally...... hiện toàn bộ
Dilaton-scalar models in the context of generalized affine gravity theories: Their properties and integrabilityPleiades Publishing Ltd - Tập 19 - Trang 209-218 - 2013
E. Davydov, A. T. Filippov
Nowadays it is widely accepted that the evolution of the Universe was driven by some scalar degrees of freedom both on its early stage and at present. The corresponding cosmological models often involve some scalar fields introduced ad hoc. In this paper we cultivate a different approach, based on a derivation of new scalar degrees of freedom from fundamental modifications of Einstein’s gravity. I...... hiện toàn bộ
Cosmological solutions in the Lovelock theory and the Einstein-Gauss-Bonnet theory with a dilatonPleiades Publishing Ltd - Tập 15 - Trang 59-61 - 2009
I. V. Kirnos, A. N. Makarenko, K. E. Osetrin
For a description of the expanding Universe agreeing with the observational data, one of the models of modified gravity is chosen, the Lovelock theory with a dilaton. We have considered an empty D-dimensional space-time with two maximally symmetric subspaces, one being 3-dimensional, the other (D-4)-dimensional. In different versions of the theory under study (in the third order without a dilaton ...... hiện toàn bộ
Weak-Field Limit of a Kaluza-Klein Model with a Nonlinear Perfect FluidPleiades Publishing Ltd - Tập 25 - Trang 349-353 - 2019
Ezgi Yalçınkaya, Alexander Zhuk
The main purpose of our paper is to construct a viable Kaluza-Klein model satisfying the observational constraints. To this end, we investigate a six-dimensional model with spherical compactification of the internal space. Background matter is considered in the form of a perfect fluid with nonlinear equations of state both in the external/our and internal spaces, and the model is set to include an...... hiện toàn bộ