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A good definition for the energy momentum tensor of gravity (EMTG) in General Relativity (GR) is a hard, if not impossible, task. On the other hand, in its teleparallel version, known as The Teleparallel Equivalent of General Relativity…

General Relativity and Quantum Cosmology · Physics 2018-12-18 J. B. Formiga

In this work, we analyze the Einstein-scalar-Gauss-Bonnet (EsGB) theory of gravity in a cosmological context using the formalism of dynamical systems. We obtain the equations of motion of the theory and introduce an appropriate set of…

General Relativity and Quantum Cosmology · Physics 2025-09-23 Miguel A. S. Pinto , João Luís Rosa

We demonstrate a new method to constrain gravity on the largest cosmological scales by combining measurements of cosmic microwave background (CMB) lensing and the galaxy velocity field. $E_G$ is a statistic, constructed from a gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-09 Anthony R. Pullen , Shadab Alam , Siyu He , Shirley Ho

This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field,…

General Relativity and Quantum Cosmology · Physics 2024-04-30 J. K. Singh , Shaily , Harshna Balhara , Sushant G. Ghosh , Sunil D. Maharaj

A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

In ``On restricting to one-loop order the radiative effects in quantum gravity" (Brandt, Frenkel, and McKeon, 2020) \cite{Brandt2020}, a Lagrange multiplier (LM) field is introduced into the Einstein-Hilbert action, removing all multi-loop…

High Energy Physics - Theory · Physics 2025-09-09 Farrukh A. Chishtie

In this work, we extend the standard cosmological model within the quadratic energy-momentum squared gravity (qEMSG) framework, introducing a nonminimal interaction between the usual material field ($T_{\mu\nu}$) and its accompanying…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 Ozgur Akarsu , Mariam Bouhmadi-López , Nihan Katirci , N. Merve Uzun

Over the last decades, tests on the standard model of cosmology, the so-called $\Lambda$CDM model, have been widely analysed and compared with many different models for describing dark energy. Modified gravities have played an important…

General Relativity and Quantum Cosmology · Physics 2024-12-13 Sergei D. Odintsov , Diego Sáez-Chillón Gómez , German S. Sharov

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

In this study, we examine the energy-momentum squared modified theory of gravity, where the squared term $T_{\mu\nu}T^{\mu\nu}$ is incorporated into the conventional gravitational Lagrangian. This modification aims to account for dark…

General Relativity and Quantum Cosmology · Physics 2025-02-03 H. R. Fazlollahi , H. Velten , H. Shojaie

In this paper, we introduce the post-Minkowskian approximation of Energy-Momentum-Squared Gravity (EMSG). This approximation is used to study the gravitational energy flux in the context of EMSG. As an application of our results, we…

General Relativity and Quantum Cosmology · Physics 2022-02-14 Elham Nazari , Mahmood Roshan , Ivan De Martino

We investigate the post-Newtonian (PN) dynamics of energy-momentum squared gravity (EMSG), with particular emphasis on the possibility of self-acceleration in $N$-body systems. A central challenge in matter-type modified gravity theories,…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Elham Nazari

We study the generalized version of energy-momentum squared gravity (EMSG) in the Palatini formalism. This theory allows the existence of a scalar constructed with energy-momentum tensor as $T_{\alpha\beta}T^{\alpha\beta}$ in the generic…

General Relativity and Quantum Cosmology · Physics 2020-09-28 Elham Nazari , Farahnaz Sarvi , Mahmood Roshan

We present updated observational constraints on the spatially flat $\phi$CDM model, where dark energy is described by a minimally coupled scalar field $\phi$ with an inverse power-law potential $V=V_0 \phi^{-\alpha}$. Using Planck 2018 CMB…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-01 Chan-Gyung Park , Bharat Ratra

Cosmological tensions can arise within $\Lambda$CDM scenario amongst different observational windows, which may indicate new physics beyond the standard paradigm if confirmed by measurements. In this article, we report how to alleviate both…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-06 Sheng-Feng Yan , Pierre Zhang , Jie-Wen Chen , Xin-Zhe Zhang , Yi-Fu Cai , Emmanuel N. Saridakis

We reconstruct the $\Lambda$CDM model for $f(T,\mathcal{T})$ Theory, where $T$ is the torsion scalar and $\mathcal{T}$ the trace of the energy-momentum tensor. The result shows that the action of $\Lambda$CDM is a combination of a linear…

General Relativity and Quantum Cosmology · Physics 2016-05-19 Ednaldo L. B. Junior , Manuel E. Rodrigues , Ines G. Salako , Mahouton J. S. Houndjo

Einstein-Gauss-Bonnet (EGB) model is recently restudied in order to analyze new consequences in gravitation, modifying appropriately the Einstein-Hilbert action. The consequences in EGB cosmology are mainly geometric, with higher order…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-02 Miguel A. García-Aspeitia , A. Hernández-Almada

The exponential $f(R)$ gravity model provides a theoretically well-motivated extension of General Relativity, introducing a modified gravitational dynamics at late times consistent with a dynamical dark energy scenario, while recovering the…

General Relativity and Quantum Cosmology · Physics 2025-11-11 Simone D'Onofrio , Sergei Odintsov , Tiziano Schiavone

The screened modified gravity (SMG) is a unified theoretical framework, which describes the scalar-tensor gravity with screening mechanism. Based on the gravitational-wave (GW) waveform derived in our previous work \citep{liu2018waveforms},…

General Relativity and Quantum Cosmology · Physics 2020-02-28 Rui Niu , Xing Zhang , Tan Liu , Jiming Yu , Bo Wang , Wen Zhao

This paper explores models of the FLRW universe that incorporate a time-varying cosmological term $\Lambda(t)$. Specifically, we assume a power-law form for the cosmological term as a function of the scale factor: $\Lambda(t)=\Lambda_{0}…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 M. Koussour , N. Myrzakulov , J. Rayimbaev