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Related papers: Perturbations in Non-Flat Cosmology for $f(T)$ gra…

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Cosmological perturbations are considered in $f(T)$ and in scalar-torsion $f(\varphi)T$ teleparallel models of gravity. Full sets of linear perturbation equations are accurately derived and analysed at the relevant limits. Interesting…

General Relativity and Quantum Cosmology · Physics 2023-01-11 Alexey Golovnev , Tomi Koivisto

We discuss linear perturbations of the most general class of teleparallel spacetimes with cosmological symmetry, and perform a decomposition of these perturbations into irreducible components. We then study their behavior under gauge…

General Relativity and Quantum Cosmology · Physics 2021-01-12 Manuel Hohmann

The universal character of the gravitational interaction provided by the equivalence principle motivates a geometrical description of gravity. The standard formulation of General Relativity \`a la Einstein attributes gravity to the…

General Relativity and Quantum Cosmology · Physics 2021-04-13 Jose Beltrán Jiménez , Lavinia Heisenberg , Tomi Sebastian Koivisto , Simon Pekar

We study linear cosmological perturbations in the most general teleparallel gravity setting, where gravity is mediated by the torsion and nonmetricity of a flat connection alongside the metric. For a general linear perturbation of this…

General Relativity and Quantum Cosmology · Physics 2023-12-22 Lavinia Heisenberg , Manuel Hohmann

We investigate the cosmological perturbations around all three branches of spatially flat universe with different connections in symmetric teleparallel gravity. The model we consider can cover both the case of f(Q) model and that of the…

General Relativity and Quantum Cosmology · Physics 2023-12-06 Haomin Rao , Chunhui Liu , Chao-Qiang Geng

In this short paper we explain how the spin connection variables should be introduced into the perturbation theory of the spatially flat cosmology in f(T) gravity with the background tetrad $e^a_{\mu}=a(t)\cdot\delta^a_{\mu}$ and zero…

General Relativity and Quantum Cosmology · Physics 2020-04-20 Alexey Golovnev

Teleparallel gravity offers a new avenue in which to construct gravitational models beyond general relativity. While teleparallel gravity can be framed in a way to be dynamically equivalent to general relativity, its modifications are…

General Relativity and Quantum Cosmology · Physics 2021-01-28 Sebastian Bahamonde , Viktor Gakis , Stella Kiorpelidi , Tomi Koivisto , Jackson Levi Said , Emmanuel N. Saridakis

We perform detailed investigation of cosmological perturbations in f(T) theory of gravity coupled with scalar field. Our work emphasizes on the way to gauge fix the theory and we examine all possible modes of perturbations up to second…

General Relativity and Quantum Cosmology · Physics 2013-06-24 Keisuke Izumi , Yen Chin Ong

There has been growing interest in $f(Q)$ gravity, which has led to significant advancements in the field. However, it is important to note that most studies in this area were based on the coincident gauge, thus overlooking the impact of…

General Relativity and Quantum Cosmology · Physics 2023-11-10 Lavinia Heisenberg , Manuel Hohmann , Simon Kuhn

We investigate the cosmological perturbations around FLRW solutions to non- linear massive gravity with a new effective coupling to matter proposed recently. Unlike the case with minimal matter coupling, all five degrees of freedom in the…

High Energy Physics - Theory · Physics 2015-06-23 A. Emir Gümrükçüoğlu , Lavinia Heisenberg , Shinji Mukohyama

We formulate cosmological perturbation theory around the spatially curved FLRW background in the context of metric-affine gauge theory of gravity which includes torsion and nonmetricity. Performing scalar-vector-tensor decomposition of the…

General Relativity and Quantum Cosmology · Physics 2024-07-18 Katsuki Aoki , Sebastian Bahamonde , Jorge Gigante Valcarcel , Mohammad Ali Gorji

In this paper, working in a Friedman-Lemaitre-Robertson-Walker (FLRW), first, in the flat case, we recover the generalized Friedman equation of Quantum Loop cosmology, and therefore the cosmological bounce, in the framework of modified…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Alessandro Casalino , Bruno Sanna , Lorenzo Sebastiani , Sergio Zerbini

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

We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this model all the dimensionful parameters like the gravitational…

General Relativity and Quantum Cosmology · Physics 2012-02-06 Pankaj Jain , Purnendu Karmakar , Subhadip Mitra , Sukanta Panda , Naveen K. Singh

The standard cosmological model, rooted in General Relativity (GR), has achieved remarkable success, yet it still faces unresolved issues like the nature of dark matter, dark energy, and the Hubble tension. These challenges might imply the…

General Relativity and Quantum Cosmology · Physics 2025-05-13 Valentina Danieli , Antonio De Felice

In this paper, a specific solution to the second-order cosmological perturbation theory is given. Perturbations are performed around any FLRW spacetime filled with dust and with a positive cosmological constant. In particular, with a…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Szymon Sikora

Symmetric Teleparallel Gravity is an exceptional theory of gravity that is consistent with the vanishing affine connection. This theory is an alternative and a simpler geometrical formulation of general relativity, where the non-metricity…

General Relativity and Quantum Cosmology · Physics 2021-07-23 Sanjay Mandal , N. Myrzakulov , P. K. Sahoo , R. Myrzakulov

We explore the cosmological implications of the local limit of nonlocal gravity, which is a classical generalization of Einstein's theory of gravitation within the framework of teleparallelism. An appropriate solution of this theory is the…

General Relativity and Quantum Cosmology · Physics 2024-04-17 Javad Tabatabaei , Abdolali Banihashemi , Shant Baghram , Bahram Mashhoon

In this paper we study cosmological perturbations in teleparallel gravity. We discuss problems which appear in standard approach to $f(T)$ gravity, and find that these problems may be solved within covariant formulation of teleparallel…

General Relativity and Quantum Cosmology · Physics 2020-09-02 A. Toporensky , P. Tretyakov

We investigate the cosmological perturbations in f(T) gravity. Examining the pure gravitational perturbations in the scalar sector using a diagonal vierbien, we extract the corresponding dispersion relation, which provides a constraint on…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Shih-Hung Chen , James B. Dent , Sourish Dutta , Emmanuel N. Saridakis
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