Results 11 to 20 of about 338,003 (249)
Energy conditions in modified f(G) gravity [PDF]
General Relativity and Gravitation, 2017 In this paper, we have considered flat Friedmann-Lema tre-Robertson-Walker metric in the framework of perfect fluid models and modified $f(G)$ gravity (where $G$ is the Gauss Bonnet invariant). Particularly, we have considered particular realistic $f(G)$ configurations that could be used to cure finite-time future singularities arising in the late ...
Kazuharu Bamba +3 more
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Energy conditions in modified gravity
Physics Letters B, 2014 We consider generalized energy conditions in modified theories of gravity by taking into account the further degrees of freedom related to scalar fields and curvature invariants. The latter are usually recast as generalized {\it geometrical fluids} that have different meanings with respect to the standard matter fluids generally adopted as sources of ...
CAPOZZIELLO, SALVATORE +2 more
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Wormhole solution in modified teleparallel-Rastall gravity and energy conditions
General Relativity and Gravitation, 2023 The possibility of static and spherically symmetric traversable wormhole solution in modified teleparallel Rastall gravity (MTRG) in a non-diagonal tetrad is investigated. Rastall assumption modifies the field equations and energy-momentum conservation law.
Nazavari, N., Saaidi, K., Mohammadi, A.
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Cosmological singularities in $$f(T,\phi ) $$ f ( T , ϕ ) gravity
European Physical Journal C: Particles and Fields, 2023 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 theories ...
Oem Trivedi +3 more
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Wormholes in viable $$f(R)$$ f ( R ) modified theories of gravity and weak energy condition [PDF]
The European Physical Journal C, 2015 In this work wormholes in viable $f(R)$ gravity models are analysed. We are interested in exact solutions for stress-energy tensor components depending on different shape and redshift functions. Several solutions of gravitational equations for different $f(R)$ models are examined.
Pavlovic, Petar, Sossich, Marko
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Results in Physics, 2023 The focus of this research is to investigate conformal vector fields (CVFs) of Bianchi type I space–times in modified teleparallel gravity (MTG). In order to determine such vector fields, we make a classification of said space–times. As a result, we discover thirty-one distinct Bianchi type I classes in the MTG.
Shabeela Malik +5 more
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Energy condition in unimodular f(R, T) gravity
European Physical Journal C: Particles and Fields, 2021 We study an interesting alternative of modified gravity theory, namely, the unimodular f(R, T) gravity in which R is the Ricci scalar and T is the trace of the stress–energy tensor. We study the viability of the model by using the energy conditions.
Fateme Rajabi, Kourosh Nozari
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Impact of curvature based geometric constraints on F(R) theory
European Physical Journal C: Particles and Fields, 2022 Theories of gravity are fundamentally a relation between matter and the geometric structure of the underlying spacetime. So once we put some additional restrictions on the spacetime geometry, the theory of gravity is bound to get the impact, irrespective
Tee-How Loo +3 more
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Quasi-cosmological traversable wormholes in f(R) gravity
European Physical Journal C: Particles and Fields, 2019 In this paper, we study traversable wormholes in the context of f(R) gravity. Exact solutions of traversable wormholes are found by imposing the nonconstant Ricci scalar. These solutions asymptotically match spherical, flat and hyperbolic FRW metric.
Hanif Golchin, Mohammad Reza Mehdizadeh
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Vanishing Cosmological Constant in Modified Gauss-Bonnet Gravity with Conformal Anomaly [PDF]
, 2006 We consider dark energy cosmology in a de Sitter universe filled with quantum conformal matter. Our model represents a Gauss-Bonnet model of gravity with contributions from quantum effects. To the General Relativity action an arbitrary function of the GB
Bergshoeff E. A. +18 more
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