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Related papers: Shear Dynamics in Higher Dimensional FLRW Cosmolog…

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Discrepancies between distance measurements and $\Lambda$CDM predictions reveal notable features in the distance-redshift relation, possibly suggesting the presence of an evolving dark energy component. Given the central role of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-06 David Camarena , Kylar Greene , John Houghteling , Francis-Yan Cyr-Racine

We construct a FLRW universe considering an anisotropic scaling between space and time at extremely high and low energies only. In this context, Friedmann equations contain an additional term arising from spatial curvature which implements…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Rodrigo Maier , Ivano Damião Soares

In the context of higher-dimensional cosmologies with isotropic visible and internal space and multi-perfect fluid matter, we study the conditions under which adiabatic expansion of the visoble external space is possible, when a…

General Relativity and Quantum Cosmology · Physics 2015-06-25 K. Kleidis , D. B. Papadopoulos

The unprecedented amount and the excellent quality of lensing data that the upcoming ground- and space-based surveys will produce represent a great opportunity to shed light on the questions that still remain unanswered concerning our…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-27 Carolina Parroni , Edouard Tollet , Vincenzo F. Cardone , Roberto Maoli , Roberto Scaramella

The evolution equation for the shear is reobtained for a spherically symmetric anisotropic, viscous dissipative fluid distribution, which allows us to investigate conditions for the stability of the shear-free condition. The specific case…

General Relativity and Quantum Cosmology · Physics 2015-05-18 L. Herrera , A. Di Prisco , J. Ospino

We examine how perturbed shear flows evolve in two-dimensional, incompressible, inviscid hydrodynamical fluids, with the ultimate goal of understanding the dynamics of accretion disks. To linear order, vorticity waves are swung around by…

Astrophysics · Physics 2009-11-13 Yoram Lithwick

In this work the role of extra dimensions in the accelerated universe through the scenario of higher-dimensional Friedmann-Robertson-Walker (FRW) cosmology has been studied. For this purpose, we first consider warped space-time in the…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-15 M. Mohsenzadeh , E. Yusofi

We analytically study coarsening dynamics in a system with nonconserved scalar order parameter, when a uniform time-independent shear flow is present. We use an anisotropic version of the Ohta-Jasnow-Kawasaki approximation to calculate the…

Statistical Mechanics · Physics 2009-10-31 Andrea Cavagna , Alan J. Bray , Rui D. M. Travasso

In braneworld models, Space-Time-Matter and other Kaluza-Klein theories, our spacetime is devised as a four-dimensional hypersurface {\it orthogonal} to the extra dimension in a five-dimensional bulk. We show that the FRW line element can…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. Ponce de Leon

We investigate the dominant physical effects of superhorizon fluctuations in a flat FLRW universe, focusing on whether the combined evolution of scalar and tensor adiabatic modes in the near-horizon regime could lead to geometries beyond…

General Relativity and Quantum Cosmology · Physics 2025-04-02 Jorge Noreña , Thiago S. Pereira , Sean K. Reynolds

We interpret as shear viscosity the anisotropic pressure that emerges in inhomogeneous spherically symmetric spacetimes described by the Lemaitre-Tolman-Bondi (LTB) metric in a comoving frame. By assuming that local isotropic pressure and…

General Relativity and Quantum Cosmology · Physics 2008-12-24 Roberto A Sussman

In this paper, we have investigated the density perturbations and cosmological evolution in the FLRW universe in presence of a cosmic magnetic field, which may be assumed to mimic primordial magnetic fields. Such magnetic fields have…

High Energy Physics - Theory · Physics 2025-08-11 Samarjit Chakraborty , Sarbari Guha

A two-dimensional Yukawa liquid is studied using two different nonequilibrium molecular dynamics simulation methods. Shear viscosity values in the limit of small shear rates are reported for a wide range of Coulomb coupling parameter and…

Soft Condensed Matter · Physics 2016-08-16 Z. Donkó , J. Goree , P. Hartmann , K. Kutasi

The shear dynamics in Bianchi I cosmological model on the brane with a perfect fluid (the equation of state is $p=(\gamma-1) \mu$) is studied. It is shown that for $1 < \gamma < 2$ the shear parameter has maximum at some moment during a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 A. V. Toporensky

We define a new observable that depends on finite redshift differences of the spin-weighted angular moments of the two point function of the three dimensional cosmic shear and on luminosity distance. It is shown that precise measurements of…

Astrophysics · Physics 2010-08-18 Ram Brustein , Daniel Levy

Bianchi type I cosmological models are studied that contain a stiff fluid with a shear viscosity that is a power function of the energy density, such as $\zeta = \alpha \epsilon^n$. These models are analyzed by describing the cosmological…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Wung-Hong Huang

Evolution of the density parameter in the anisotropic DGP braneworld model is studied. The role of shear and cross-over scale in the evolution of $\Omega_\rho$ is examined for both the branches of solution in the DGP model. The evolution is…

General Relativity and Quantum Cosmology · Physics 2011-12-23 Rizwan Ul Haq Ansari , P. K. Suresh

We study FRW cosmology for scalar tensor theory where two scalar functions nonminimally coupled to the geometry and matter Lagrangian. In a framework to study stability and attractor solutions of the model in the phase space, we…

General Relativity and Quantum Cosmology · Physics 2011-11-22 Hossein Farajollahi , Amin Salehi , Mohammad Nasiri

We study the conditions for the consistency of the Friedmann-Robertson-Walker (FRW) metric with the dynamical Chern-Simons modified gravity. It turns out to be that in this situation the accelerated expansion of the Universe takes place,…

High Energy Physics - Theory · Physics 2011-07-14 C. Furtado , J. R. Nascimento , A. Yu. Petrov , A. F. Santos

Accelerating cosmologies in extra dimensional spaces have been studied. These extra dimensional spaces are products of many spaces. The physical behaviors of accelerating cosmologies are investigated from Einstein's field equation in higher…

Astrophysics · Physics 2008-10-16 Han Siong Ch'ng