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Related papers: Energy Conditions in $f(Q)$ gravity

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Despite the significant accomplishments of general relativity, numerous unresolved issues persist in our understanding of the cosmos. One of the most perplexing challenges is the ongoing accelerated expansion of the Universe, which…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-22 M. Koussour , N. Myrzakulov , Alnadhief H. A. Alfedeel , Amare Abebe

In this work, the classical Godel solution from general relativity is extended into the framework of modified gravity theories based on non-metricity $Q$ and the trace of the energy-momentum tensor $T$ in the context of $f(Q,T)$ gravity.…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Tuhina Ghorui , Prabir Rudra , Farook Rahaman

The late-time acceleration of the universe remains one of the most significant open problems in modern cosmology. Modified gravity frameworks such as $f(T)$ gravity provide a geometric alternative to dark energy by attributing cosmic…

General Relativity and Quantum Cosmology · Physics 2026-05-07 Anirudh Pradhan , S. A. Salve , V. B. Raut , S. H. Shekh

In the context of extended theories of teleparallel gravity $f(T)$ we derive the focusing conditions for a one-parameter dependent congruence of timelike auto-parallels of the Levi-Civita connection. We also consider the $f(T)$ field…

General Relativity and Quantum Cosmology · Physics 2020-12-14 U. K. Beckering Vinckers , A. de la Cruz-Dombriz , F. J. Maldonado Torralba

The pursuit of understanding the mysteries surrounding dark energy has sparked significant interest within the field of cosmology. While conventional approaches, such as the cosmological constant, have been extensively explored, alternative…

General Relativity and Quantum Cosmology · Physics 2024-08-02 Oem Trivedi , Maxim Khlopov , Jackson Levi Said , Rafael C. Nunes

This study explores the extension of teleparallel gravity within the framework of general relativity, introducing an algebraic function $f(T)$ dependent on the torsion scalar $T$. Motivated by the teleparallel formulation, we investigate…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-30 M. Koussour , A. Altaibayeva , S. Bekov , F. Holmurodov , S. Muminov , J. Rayimbaev

This thesis investigates late-time cosmic acceleration using modified gravity theories with a focus on $f(Q)$ gravity, as an alternative to the $\Lambda$CDM model. The standard cosmological model attributes the acceleration to a…

General Relativity and Quantum Cosmology · Physics 2025-12-18 S. A. Narawade

This note summarizes a model-independent analysis of the age of the universe problem that trades off precision in favour of robustness: The energy conditions of Einstein gravity are designed to extract as much information as possible from…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Matt Visser

Symmetric teleparallel gravity theories, in which the gravitational interaction is attributed to the nonmetricity of a flat, symmetric, but not metric-compatible affine connection, have been a topic of growing interest in recent studies.…

General Relativity and Quantum Cosmology · Physics 2022-01-03 Manuel Hohmann

In this work we study the cosmology of the general f(T) gravity theory. We express the modified Einstein equations using covariant quantities, and derive the gauge-invariant perturbation equations in covariant form. We consider a specific…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-02 Baojiu Li , Thomas P. Sotiriou , John D. Barrow

The null energy condition has sweeping consequences in general relativity. I argue here that it has been misunderstood as a property exclusively of matter, when in fact it arises only in a theory of both matter and gravity. I then derive an…

High Energy Physics - Theory · Physics 2015-12-14 Maulik Parikh

This paper explores the generalized ghost dark energy model in the framework of $f(\textsl{Q}, \textsl{L}_{m})$ gravity, where $\textsl{Q}$ represents the non-metricity scalar and $\textsl{L}_{m}$ denotes the matter-Lagrangian density. We…

General Relativity and Quantum Cosmology · Physics 2025-01-03 M. Zeeshan Gul , M. Sharif , Shan Ali Qureshi , Baiju Dayanandan

Explanations of the late-time cosmic acceleration within the framework of general relativity are plagued by difficulties. General relativistic models are mostly based on a dark energy field with fine-tuned, unnatural properties. There is a…

Astrophysics · Physics 2010-04-22 Ruth Durrer , Roy Maartens

This paper elaborates the problem of energy-momentum in the framework of teleparallel equivalent of General Relativity. For this purpose, we consider energy-momentum prescription derived from the integral form of the constraint equations…

General Relativity and Quantum Cosmology · Physics 2010-01-07 M. Sharif , Sumaira Taj

A possible astrophysical object to be found in General Relativity is the wormhole. This special solution describes a topological bridge connecting points in two distinguished universes or two different points in the same universe. Despite…

General Relativity and Quantum Cosmology · Physics 2023-06-21 Moreshwar Tayde , Joao R. L. Santos , Julia N. Araujo , P. K. Sahoo

In this paper, we discuss the Bianchi type-I cosmological model in the framework of symmetric teleparallel gravity say $f(Q)$ gravity in which the non-metricity term $Q$ is responsible for the gravitational interaction. We consider a…

General Relativity and Quantum Cosmology · Physics 2023-04-05 M. Koussour , S. H. Shekh , M. Govender , M. Bennai

A viable radiation dominated era in the early universe is best described by the standard (FLRW) model of cosmology. In this short review, we demonstrate reconstruction of the forms of F(R) in the modified theory of gravity and the metric…

General Relativity and Quantum Cosmology · Physics 2024-01-23 Dalia Saha , Manas Chakrabortty , Abhik Kumar Sanyal

This paper studies the reconstruction criterion in the framework of $f(Q,T)$ gravity using ghost dark energy model, where $Q$ represents the non-metricity and $T$ is the trace of energy-momentum tensor. In this regard, the correspondence…

General Relativity and Quantum Cosmology · Physics 2024-05-09 M. Sharif , Iqra Ibrar

A standard line in the contemporary philosophical literature has it that physical theories are equivalent only when they agree on their empirical content, where this empirical content is often understood as being encoded in the equations of…

History and Philosophy of Physics · Physics 2024-02-20 William J. Wolf , James Read

In this paper, we have introduced a new $f(R)$ gravity model as an attempt to have a model with more parametric control, so that the model can be used to explain the existing problems as well as to explore new directions in physics of…

General Relativity and Quantum Cosmology · Physics 2020-12-03 Dhruba Jyoti Gogoi , Umananda Dev Goswami