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Related papers: $f(Q,L_m)$ gravity, and its cosmological implicati…

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We investigate the geometrodynamical effects of introducing the boundary term in symmetric teleparallel gravity. Specifically, we consider a homogeneous and isotropic universe in $f\left( Q, B \right) $, where $Q$ is the non-metricity…

General Relativity and Quantum Cosmology · Physics 2023-09-27 Andronikos Paliathanasis

In this paper, we consider a theory of gravity with a metric-dependent torsion namely the $F(R,T)$ gravity, where $R$ is the curvature scalar and $T$ is the torsion scalar. We study a geometric root of such theory. In particular we give the…

General Relativity and Quantum Cosmology · Physics 2012-11-20 Ratbay Myrzakulov

Over the past decades, the role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description. Here we review various…

General Relativity and Quantum Cosmology · Physics 2016-09-09 Yi-Fu Cai , Salvatore Capozziello , Mariafelicia De Laurentis , Emmanuel N. Saridakis

Since the discovery of cosmic acceleration, modified gravity theories play an important role in the modern cosmology. In particular, the well-known F(R) - theories reached great popularity motivated by the easier formalism and by the…

General Physics · Physics 2024-06-03 Ratbay Myrzakulov

The existence of self-similar solutions is discussed in symmetric teleparallel $f(Q)$-theory for a Friedmann-Lema\^itre-Robertson-Walker background geometry with zero and non-zero spatial curvature. For the four distinct families of…

General Relativity and Quantum Cosmology · Physics 2022-12-01 N. Dimakis , M. Roumeliotis , A. Paliathanasis , P. S. Apostolopoulos , T. Christodoulakis

Recently a class of alternative theories of gravity which goes under the name f(R) gravity, has received considerable attention, mainly due to its interesting applications in cosmology. However, the phenomenology of such theories is not…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thomas P. Sotiriou , Stefano Liberati

In this work, we review a plethora of modified theories of gravity with generalized curvature-matter couplings. The explicit nonminimal couplings, for instance, between an arbitrary function of the scalar curvature $R$ and the Lagrangian…

General Relativity and Quantum Cosmology · Physics 2014-07-29 Tiberiu Harko , Francisco S. N. Lobo

We consider cosmological modelling in $f(R)$ theories of gravity, using both top-down and bottom-up constructions. The top-down models are based on Robertson-Walker geometries, and the bottom-up constructions are built by patching together…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Timothy Clifton , Peter K. S. Dunsby

In general relativity (GR), the metric tensor of spacetime is essential since it represents the gravitational potential. In other gauge theories (such as electromagnetism), the so-called premetric approach succeeds in separating the purely…

General Relativity and Quantum Cosmology · Physics 2017-04-18 Yakov Itin , Friedrich W. Hehl , Yuri N. Obukhov

The present work studies one of Einstein's alternative formulations based on the non-metricity scalar $Q$ generalized as $f(Q)$ theory. More specifically, we consider the power-law form of $f(Q)$ gravity i.e. $f(Q)=Q+\alpha\, Q^n$. Here, we…

General Relativity and Quantum Cosmology · Physics 2021-05-26 Wompherdeiki Khyllep , Andronikos Paliathanasis , Jibitesh Dutta

General relativity can be formulated equivalently with a non-Riemannian geometry that associates with an affine connection of nonzero nonmetricity $Q$ but vanishing curvature $R$ and torsion $T$. Modification based on this description of…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Rui-Hui Lin , Xiang-Hua Zhai

We consider the teleparallel equivalent of Lovelock gravity and its natural extension, where the action is given by an arbitrary function $f(T_{_{L_1}}, T_{_{L_2}},\cdot \cdot \cdot , T_{_{L_n}})$ of the torsion invariants $T_{_{L_i}}$,…

General Relativity and Quantum Cosmology · Physics 2019-07-31 P. A. González , Samuel Reyes , Yerko Vásquez

There is ongoing interest in the nonmetricity formulation of gravity. The nonlinear extension of the theory, called $f(Q)$ gravity, has recently been proposed and offers a promising avenue for addressing some of the long-standing challenges…

General Relativity and Quantum Cosmology · Physics 2024-09-23 A. M. Silva , M. J. Rebouças , N. A. Lemos

In Einstein's General Relativity (GR), the gravitational interactions are described by the spacetime curvature. Recently, other alternative geometric formulations and representations of GR have emerged in which the gravitational…

General Relativity and Quantum Cosmology · Physics 2023-08-16 A. Hanin , M. Koussour , Z. Sakhi , M. Bennai

General Relativity (GR), with or without matter fields, admits a natural extension to a scale invariant theory that requires a dilaton. Here we show that the recently formulated massive GR, minimally coupled to matter, possesses a new…

High Energy Physics - Theory · Physics 2013-04-03 Guido D'Amico , Gregory Gabadadze , Lam Hui , David Pirtskhalava

The cosmological implications of the Covariant Canonical Gauge Theory of Gravity (CCGG) are investigated. We deduce that, in a metric compatible geometry, the requirement of covariant conservation of matter invokes torsion of space-time. In…

General Relativity and Quantum Cosmology · Physics 2024-10-28 David Vasak , Johannes Kirsch , Juergen Struckmeier

We explore the geometrical meaning of teleparallel geometries and the role of covariance in their definition. We argue that pure gauge connections are a necessary ingredient for describing geometry and gravity in terms of torsion and…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Martin Krššák

The fundamental nature and origin of dark energy are one of the premier mysteries of theoretical physics. In General Relativity Theory, the cosmological constant $\Lambda$ is the simplest explanation for dark energy. On the other hand, the…

General Relativity and Quantum Cosmology · Physics 2022-05-27 Raja Solanki , Avik De , Sanjay Mandal , P. K. Sahoo

In this study, we examined the late-time cosmic expansion of the universe within the framework of $f(Q, L_m)$ gravity, where $Q$ denotes the non-metricity and $L_{m}$ represents the matter Lagrangian. We analyzed a linear $f(Q, L_m)$ model…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-15 Yerlan Myrzakulov , O. Donmez , M. Koussour , D. Alizhanov , S. Bekchanov , J. Rayimbaev

We perform a phase space analysis of a non-minimally coupled modified gravity theory with the Lagrangian density of the form $\frac{1}{2} f_{1}(R)+[1+\lambda f_{2}(R)]{{\cal{L}}_{m}}$, where $f_1(R)$ and $f_2(R)$ are arbitrary functions of…

General Relativity and Quantum Cosmology · Physics 2014-06-03 Tahereh Azizi , Emad Yaraie