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Related papers: Finslerian perturbation for the $\Lambda$CDM model

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This work investigates the nonlinearity of the power-law model of F(T) gravity, highlighting the inability of the Boltzmann solver CLASS to handle nonlinear models. As a workaround, a second-order Taylor expansion is applied to the…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Robert Rugg , Shambel Akalu , Amare Abebe

Horava and Melby-Thompson recently proposed a new version of the Horava-Lifshitz theory of gravity, in which the spin-0 graviton is eliminated by introducing a Newtonian pre-potential $\phi$ and a local U(1) gauge field $A$. In this paper,…

High Energy Physics - Theory · Physics 2011-02-23 Anzhong Wang , Yumei Wu

In this paper we give five gauge-invariant systems of governing equations for first and second order scalar perturbations of flat Friedmann-Lema\^{i}tre universes that are minimal in the sense that they contain no redundant equations or…

General Relativity and Quantum Cosmology · Physics 2019-01-23 Claes Uggla , John Wainwright

We present a proposal to include Lorentz-violating effects in gravitational field by means of the Finsler geometry. In the Finsler set up, the length of an event depends both on the point and the direction in the space-time. We briefly…

High Energy Physics - Theory · Physics 2017-08-23 J. Euclides G. Silva , C. A. S. Almeida

We consider the primordial gravitational wave (GW) background in a class of spatially-flat inflationary cosmological models with cold dark matter (CDM), a cosmological constant, and a broken-scale-invariant (BSI) steplike primordial…

Astrophysics · Physics 2009-10-30 J. Lesgourgues , D. Polarski , A. A. Starobinsky

In this analysis, we study the dynamics of quantum oscillator fields within the context of a position-dependent mass (PDM) system situated in an Einstein-Maxwell space-time, incorporating a non-zero cosmological constant. The magnetic field…

General Relativity and Quantum Cosmology · Physics 2024-06-10 Faizuddin Ahmed , Abdelmalek Bouzenada

The similarity between Finsler and Riemann geometry is an intriguing starting point to extend general relativity. The lack of quadratic restriction over the line element (color) naturally generalize the Riemannian case and breaks the local…

General Relativity and Quantum Cosmology · Physics 2015-06-11 A. P. Kouretsis , M. Stathakopoulos , P. C. Stavrinos

Within the context of supersymmetric space-time (D-particle) foam in string/brane-theory, we discuss a Finsler-induced Cosmology and its implications for (thermal) Dark Matter abundances. This constitutes a truly microscopic model of…

High Energy Physics - Phenomenology · Physics 2012-04-03 Nick E. Mavromatos , Vasiliki A. Mitsou , Sarben Sarkar , Ariadne Vergou

We investigate the inhomogeneous inflation, in which the space exponentially expands with inhomogeneities, and its cosmological perturbations. The inhomogeneous inflation is realized by introducing scalar fields with spacelike gradients…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-11 Xian Gao , Chao Kang

We consider the generation of primordial curvature perturbation by general non-Abelian vector fields without committing to a particular group. Self-interactions of non-Abelian fields make the field perturbation non-Gaussian. We calculate…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-10 Mindaugas Karciauskas

We consider the evolution of cosmological gravitational waves in scalar-tensor theory and $F(R)$ gravity theory as typical models of the modified gravity. Although the propagation speed is not changed from the speed of light, the…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Shin'ichi Nojiri , Sergei D. Odintsov

Within the framework of the Finslerian approach to the problem of violation of Lorentz symmetry, consideration is given to a flat axially symmetric Finslerian space of events, which is the generalization of Minkowski space. Such an event…

High Energy Physics - Theory · Physics 2008-11-26 G. Yu. Bogoslovsky

In this work we explore the possibility of variations in the primordial scalar power spectrum around the power-law shape, as predicted by single-field slow-roll inflationary scenarios. We search for the trace of these fluctuations in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Marzieh Farhang , Muhammad Sadegh Esmaeilian

We study the growth of cosmological perturbations in the model of Lorentz-violating massive gravity. The Friedman equation in this model acquires an unconventional term due to the Lorentz-breaking condensates which has the equation of state…

Astrophysics · Physics 2008-12-18 Michael V. Bebronne , Peter G. Tinyakov

In a suitably chosen essentially unique frame tied to a given observer in a general spacetime, the equation of geodesic deviation can be decomposed into a sum of terms describing specific effects: isotropic (background) motions associated…

General Relativity and Quantum Cosmology · Physics 2009-10-31 J. Bicak , J. Podolsky

We investigate the linear cosmological perturbations in the context of the so-called energy-momentum squared gravity (EMSG) theory. Recent researches show that the EMSG theory can reproduce viable background cosmological evolution…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-17 Qi-Ming Fu , Xin Zhang

The $f(R)$ theory of gravitation developed perturbatively around the general theory of relativity with cosmological constant (the \text{$\Lambda$}CDM model) in a flat FLWR geometry is considered. As a result, a general explicit cosmological…

General Relativity and Quantum Cosmology · Physics 2025-02-25 Pham Van Ky , Nguyen Thi Hong Van , Nguyen Anh Ky

The Hubble constant proves to be the pseudo-Finsleroid--Landsberg factor. The covariantly conserved pseudo-Finsleroid--gravitational tensor is explicitly found after evaluating the respective Finsleroid--case curvature tensor and required…

Mathematical Physics · Physics 2007-07-24 G. S. Asanov

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-07 Saroj Adhikari , Dragan Huterer

We consider quintessence scalar field cosmology in which the Lagrangian of the scalar field is modified by the Generalized Uncertainty Principle. We show that the perturbation terms which arise from the deformed algebra are equivalent with…

General Relativity and Quantum Cosmology · Physics 2015-12-03 Andronikos Paliathanasis , Supriya Pan , Souvik Pramanik
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