English
Related papers

Related papers: Induced cosmological anisotropy by a gauge-gravity…

200 papers

Accelerating cosmological models are constructed in a modified gravity theory dubbed as $f(R,T)$ gravity at the backdrop of an anisotropic Bianchi type-III universe. $f(R,T)$ is a function of the Ricci scalar $R$ and the trace $T$ of the…

General Relativity and Quantum Cosmology · Physics 2017-06-21 S K Sahu , S K Tripathy , P K Sahoo , A Nath

Scalar field cosmologies with a generalized harmonic potential and matter with energy density $\rho_m$, pressure $p_m$, and barotropic equation of state (EoS) $p_m=(\gamma-1)\rho_m, \; \gamma\in[0,2]$ in Kantowski-Sachs (KS) and closed…

General Relativity and Quantum Cosmology · Physics 2021-08-09 Genly Leon , Esteban González , Samuel Lepe , Claudio Michea , Alfredo D. Millano

The major contribution to the anisotropy of the temperature of the Cosmic Microwave Background (CMB) radiation is believed to come from the interaction of linear density perturbations with the radiation previous to the decoupling time.…

Astrophysics · Physics 2015-06-24 Enrique Martinez-Gonzalez

We study the asymptotic dynamics of $f(T, B)$-theory in an anisotropic Bianchi III background geometry. We show that an attractor always exists for the field equations, which depends on a free parameter provided by the specific $f(T, B)$…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Genly Leon , Andronikos Paliathanasis

Cosmography is a widely applied method to infer kinematics of the Universe at small cosmological scales while remaining agnostic about the theory of gravity at play. Usually cosmologists invoke the Friedmann-Lemaitre-Robertson-Walker (FLRW)…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-25 Hayley J. Macpherson , Asta Heinesen

Massive bigravity models are interesting alternatives to standard cosmology. In most cases, however, these models have been studied for a simplified scenario in which both metrics take homogeneous and isotropic forms…

General Relativity and Quantum Cosmology · Physics 2015-11-18 Henrik Nersisyan , Yashar Akrami , Luca Amendola

We use numerical simulations to calculate the cosmic microwave background anisotropy induced by the evolution of a global texture field, with special emphasis on individual textures. Both spherically symmetric and general configurations are…

We show that, in quadratic lagrangian theories of gravity, isotropic cosmological singularities are stable to the presence of small scalar, vector and tensor inhomogeneities. Unlike in general relativity, a particular exact isotropic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John D. Barrow , Jonathan Middleton

We study curvature perturbations in the anisotropic inflationary model with a complex scalar field charged under a $U(1)$ gauge field in Bianchi I universe. Due to Abelian Higgs mechanism, the gauge field receives an additional longitudinal…

High Energy Physics - Theory · Physics 2015-06-12 Razieh Emami , Hassan Firouzjahi

We show that modified gravity presents distinctive nonlinear features on the Cosmic Microwave Background (CMB) anisotropies comparing with General Relativity (GR). We calculate the contribution to the CMB non-Gaussianity from nonlinear…

General Relativity and Quantum Cosmology · Physics 2011-08-09 Xian Gao

We investigate FLRW cosmology in the framework of symmetric teleparallel $f(Q)$ gravity with a nonminimal coupling between dark matter and the gravitational field. In the noncoincidence gauge, the field equations admit an equivalent…

General Relativity and Quantum Cosmology · Physics 2026-03-26 A. Abebe , P. S. Apostolopoulos , A. Giacomini , G. Leon , F. Moncada , A. Paliathanasis

In the context of modified tele-parallel theory of gravity, we undertake cosmological anisotropic models and search for their solutions. Within a suitable choice of non-diagonal tetrads, the decoupled equations of motion are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-25 M. E. Rodrigues , A. V. Kpadonou , F. Rahaman , P. J. Oliveira , M. J. S. Houndjo

We demonstrate a severe Fermi contour anisotropy induced by the application of a parallel magnetic field to high-mobility electrons confined to a 30-nm-wide (001) GaAs quantum well. We study commensurability oscillations, namely geometrical…

Strongly Correlated Electrons · Physics 2015-06-16 D. Kamburov , M. A. Mueed , M. Shayegan , L. N. Pfeiffer , K. W. West , K. W. Baldwin , J. J. D. Lee , R. Winkler

This paper studies the effect of anisotropy on sharp or diffuse interfaces models. When the surface tension is a convex function of the normal to the interface, the anisotropy is said to be weak. This usually ensures the lower…

Analysis of PDEs · Mathematics 2025-10-16 Jean-François Babadjian , Blanche Buet , Michael Goldman

Recent measurements using catalogues of quasars and radio galaxies have shown that the dipole anisotropy in the large-scale distribution of matter is about twice as large as is expected in the standard $\Lambda$CDM model, indeed in any…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-15 Sebastian von Hausegger

We propose a new model to generate large anisotropies in the scalar-induced gravitational wave (SIGW) background via sound speed resonance in the inflaton-curvaton mixed scenario. Cosmological curvature perturbations are not only…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-03 Yan-Heng Yu , Sai Wang

Deviations from isotropy have been a key tool to identify the sources and the primary type of cosmic rays (CRs) at low energies. We argue that anisotropies due to blind regions induced by the Galactic magnetic field, the cosmological…

Astrophysics · Physics 2008-11-26 M. Kachelriess

We present the reconstruction method of $f(R)$ gravity for the homogeneous and anisotropic Bianchi-I spacetime, which was previously formulated only for homogeneous and isotropic FLRW spacetime. We argue in this paper that for anisotropic…

General Relativity and Quantum Cosmology · Physics 2018-07-11 Saikat Chakraborty

We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-18 Razieh Emami , Hassan Firouzjahi , S. M. Sadegh Movahed , Moslem Zarei

The standard $\Lambda$CDM cosmological model faces increasing tensions between key observations, motivating tests that probe its underlying assumptions. In a companion letter, we present a model-independent framework that combines…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 S. M. Koksbang , A. Heinesen