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Related papers: Herglotz Action for Homogeneous Cosmology

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We consider a spatially homogeneous and isotropic cosmological model where Dirac spinors are coupled to classical gravity. For the Dirac spinors we choose a Hartree-Fock ansatz where all one-particle wave functions are coherent and have the…

Mathematical Physics · Physics 2014-04-23 Felix Finster , Christian Hainzl

We present two methods for describing, from a pedagogical point of view, the solutions of Einstein's equations applied to a homogeneous and isotropic universe. In the first method, we define an effective gravitational potential of the…

Physics Education · Physics 2007-05-23 L. Arturo Ureña--López

The Hamiltonian approach to General Relativity is developed similarly to the Wheeler-DeWitt Hamiltonian cosmology, where the cosmological scale factor is treated as a time-like dynamic variable and its canonical momentum is considered as an…

Astrophysics · Physics 2007-05-23 B. M. Barbashov , V. N. Pervushin , V. A. Zinchuk , A. G. Zorin

Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields, quant-ph/9902015). The unreduced interaction analysis gives intrinsically creative…

General Physics · Physics 2007-05-23 Andrei P. Kirilyuk

We demonstrate that to all large scale cosmological structures where gravitation is the only overall relevant interaction assembling the system (e.g. galaxies), there is associated a characteristic unit of action per particle whose order of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Salvatore Capozziello , Salvatore De Martino , Silvio De Siena , Fabrizio Illuminati

The dynamics of a universe dominated by a self-interacting nonminimally coupled scalar field are considered. The structure of the phase space and complete phase portraits are given. New dynamical behaviors include superinflation…

General Relativity and Quantum Cosmology · Physics 2009-10-31 E. Gunzig , A. Saa , L. Brenig , V. Faraoni , T. M. Rocha Filho , A. Figueiredo

We write a non-relativistic Lagrangian for a hierarchical universe. The equations of motion are solved numerically and the evolution of the fractal dimension is obtained for different initial conditions. We show that our model is…

Astrophysics · Physics 2011-05-23 E. Abdalla , N. Afshordi , K. Khodjasteh , R. Mohayaee

We consider the quantized bi-scalar gravity, which may serve as a locally Lorentz invariant cosmological model with varying speed of light and varying gravitational constant. The equation governing the quantum regime for the case of…

General Relativity and Quantum Cosmology · Physics 2023-10-02 Adam Balcerzak , Mateusz Lisaj

In this paper we develop an abstract setup for hamiltonian group actions as follows: Starting with a continuous 2-cochain $\omega$ on a Lie algebra $h$ with values in an $h$-module $V$, we associate subalgebras $sp(h,\omega) \supeq…

Symplectic Geometry · Mathematics 2011-11-17 Karl-Hermann Neeb , Cornelia Vizman

A framework is introduced which explains the existence and similarities of most exact solutions of the Einstein equations with a wide range of sources for the class of hypersurface-homogeneous spacetimes which admit a Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Claes Uggla , Robert T. Jantzen , Kjell Rosquist

We study the action of Bogoliubov transformations on admissible generalized one-particle density matrices arising in Hartree-Fock-Bogoliubov theory. We show that the orbits of this action are reductive homogeneous spaces, and we give…

Functional Analysis · Mathematics 2024-02-27 Claudia D. Alvarado , Eduardo Chiumiento

We propose a scale-dependent cosmology in which the Robertson--Walker metric and the Einstein equation are modified in such a way that $\Omega_0$, $H_0$ and the age of the Universe all become scale-dependent. Its implications on the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Chung Wook Kim , JeongHyeon Song

Universe structure emerges in the unreduced, complex-dynamical interaction process with the simplest initial configuration (two attracting homogeneous fields). The unreduced interaction analysis avoiding any perturbative model gives…

General Physics · Physics 2015-03-20 Andrei P. Kirilyuk

All classes of spatially homogeneous space-time models are found that allow the integration of the equations of motion of test particles and the eikonal equation by the method of complete separation of variables according to type (2.1).…

General Relativity and Quantum Cosmology · Physics 2020-08-26 Evgeny Osetrin , Konstantin Osetrin , Altair Filippov

We address the implementation of the cosmological principle, that is, the assumption of homogeneity and isotropy in the spatial distribution of matter in the Universe, within the context of Einstein-Cartan theory including minimal couplings…

General Relativity and Quantum Cosmology · Physics 2020-11-03 Francisco Cabral , Francisco S. N. Lobo , Diego Rubiera-Garcia

Advantages of inhomogeneous cosmological models that are exact solutions of Einstein's equations over linearised perturbations of homogeneous models are presented. Examples of effects that can be described in the inhomogeneous ones are…

General Relativity and Quantum Cosmology · Physics 2011-12-05 Andrzej Krasiński

Dark energy is one of the deepest puzzles in modern cosmology, and mounting evidence suggests that it is not just a cosmological constant but a genuinely dynamical component. Although cosmology and dynamical systems theory emerged from…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Nandan Roy , L. Arturo Ureña-López

The "Newtonian" or non-relativistic decomposition of Einstein's gravitational field is useful in the post-Newtonian approximation. We obtain the full non-quadratic Einstein-Hilbert action in terms of these fields as well as the harmonic…

High Energy Physics - Theory · Physics 2012-11-08 Barak Kol , Michael Smolkin

Based on recent results from general relativistic statistical mechanics and black hole information transfer limits a space-time entropy-action equivalence is proposed as a generalization of the holographic principle. With this conjecture,…

General Relativity and Quantum Cosmology · Physics 2021-09-08 Joakim Munkhammar

Some exact solutions for the Einstein field equations corresponding to inhomogeneous $G_2$ cosmologies with an exponential-potential scalar field which generalize solutions obtained previously are considered. Several particular cases are…

General Relativity and Quantum Cosmology · Physics 2016-08-15 A. Feinstein , J. Ibáñez , P. Labraga
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