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Cosmological Dynamics of Interacting Dark Energy and Dark Matter in f(Q)$f(Q)$ Gravity

Fortschritte der Physik, Volume 73, Issue 5, May 2025.
Abstract In this work, the behavior of interacting dark energy (DE) and dark matter (DM) within a model of f(Q)$f(Q)$ gravity is explored, employing the standard framework of dynamical system analysis. The power‐law f(Q)$f(Q)$ model is considered, incorporating two different forms of interacting DE and DM: 3αHρm$3\alpha H\rho _m$ and α3HρmρDE$\frac ...
Gaurav N. Gadbail, Simran Arora, Phongpichit Channuie, P. K. Sahoo   +3 more
wiley   +1 more source

Thermodynamic Interpretation of the Kompanneets–Chernov–Kantowski–Sachs Solutions

Universe
The spatially homogeneous perfect fluid solutions by Kompanneets–Chernov–Kantowski–Sachs are interpreted as a thermodynamic perfect fluid in isentropic evolution, namely, the isentropic limit of their non-homogeneous generalizations, the T-models.
Salvador Mengual, Joan Josep Ferrando
doaj   +1 more source

Euler–Heisenberg Black Hole Surrounded by Quintessence in the Background of Perfect Fluid Dark Matter: Thermodynamics, Shadows, and Quasinormal Modes

Fortschritte der Physik, Volume 73, Issue 3, March 2025.
Abstract Current observations show that a significant fraction of the Universe is composed of dark energy and dark matter. In this paper, the simultaneous effects of these dark sectors on the Euler–Heisenberg black hole are investigated, using the quintessence matter field and perfect fluid to model them. In particular, the black hole's thermodynamics,
Bilel Hamil, Bekir Can Lütfüoğlu
wiley   +1 more source

Conformal Mappings in Relativistic Astrophysics

Journal of Applied Mathematics, 2013
We describe the use of conformal mappings as a mathematical mechanism to obtain exact solutions of the Einstein field equations in general relativity. The behaviour of the spacetime geometry quantities is given under a conformal transformation, and the ...
S. Hansraj, K. S. Govinder, N. Mewalal
doaj   +1 more source

Revealing noncanonical Hamiltonian structures in relativistic fluid dynamics

Fundamental Plasma Physics
We present the noncanonical Hamiltonian structure of the relativistic Euler equations for a perfect fluid in Minkowski spacetime. By identifying the system’s noncanonical Poisson bracket and Hamiltonian, we show that relativistic fluid flows preserve ...
Keiichiro Takeda, Naoki Sato
doaj   +1 more source

A class of higher-dimensional solutions of Einstein’s vacuum equation

European Physical Journal C: Particles and Fields, 2019
A new class of higher-dimensional exact solutions of Einstein’s vacuum equation is presented. These metrics are written in terms of the exponential of a symmetric matrix and when this matrix is diagonal the solution reduces to higher-dimensional ...
Gabriel Luz Almeida, Carlos Batista
doaj   +1 more source

Impacts of perfect fluid dark matter on spacetime geometry: the exponential metric

European Physical Journal C: Particles and Fields
Astrophysical observations provide compelling evidence for the existence of dark matter, a non-luminous component dominating the universe’s mass-energy budget.
Jan Kuncewicz
doaj   +1 more source

Characterisation of orthogonal perfect fluid cosmological spacetimes

, 1994
We consider the general orthogonal metric separable in space and time variables in comoving coordinates. We then characterise perfect fluid models admitted by such a metric. It turns out that the homogeneous models can only be either FLRW or Bianchi I while the inhomogeneous ones can only admit $G_2 $ (two mutually as well as hypersurface orthogonal ...
Dadhich, Naresh, Patel, L. K., Govinder, K. S., Leach, P. G. L.   +3 more
openaire   +2 more sources

The Gibbs Paradox, the Landauer Principle and the Irreversibility Associated with Tilted Observers

Entropy, 2017
It is well known that, in the context of General Relativity, some spacetimes, when described by a congruence of comoving observers, may consist of a distribution of a perfect (non–dissipative) fluid, whereas the same spacetime as seen by a “tilted ...
Luis Herrera
doaj   +1 more source

Almost Schouten solitons and perfect fluid spacetimes

Filomat
In this study, we assume that a perfect fluid is the source of the gravitational field while analyzing the solutions to the Einstein field equations. With this new and innovative approach, we study almost Schouten and gradient Schouten solitons on perfect fluid spacetimes.
Arpan Sardar, Changhwa Woo, Uday De
openaire   +1 more source