Results 11 to 20 of about 24,685 (268)

Energy conditions in modified gravity

Physics Letters B, 2014
4 pages. V2: 5 pages; version to appear in Physics Letters B. V3: typo in Eq.
CAPOZZIELLO, SALVATORE, Francisco S. N. Lobo, Jos? P. Mimoso   +2 more
openaire   +4 more sources

Irreversible Geometrothermodynamics of Open Systems in Modified Gravity

Entropy, 2023
In this work, we explore the formalism of the irreversible thermodynamics of open systems and the possibility of gravitationally generated particle production in modified gravity.
Miguel A. S. Pinto, Tiberiu Harko, Francisco S. N. Lobo   +2 more
doaj   +2 more sources

Energy conditions in Gauss–Bonnet gravity

European Physical Journal C: Particles and Fields
We study the Energy Conditions in modified $$f(\mathcal {G})$$ f ( G ) gravity, with $$\mathcal {G}$$ G being the topological Gauss–Bonnet term. Then we use the cosmographic parameters to constrain the functional form of the gravitational action and ...
Francesco Bajardi
doaj   +2 more sources

Reconstruction of energy conditions from observations and implications for extended theories of gravity

European Physical Journal C: Particles and Fields, 2019
The attempt to describe the recent accelerated expansion of the Universe includes different propositions for dark energy models and modified gravity theories.
M. Penna-Lima, S. D. P. Vitenti, M. E. S. Alves, J. C. N. de Araujo, F. C. Carvalho   +4 more
doaj   +2 more sources

Anisotropic Quintessence Strange Stars in f(T) Gravity with Modified Chaplygin Gas

Advances in High Energy Physics, 2018
In this paper, we study the existence of strange star in the background of f(T) modified gravity where T is a scalar torsion. In KB metric space, we derive the equations of motion using anisotropic property within the spherically strange star with ...
Pameli Saha, Ujjal Debnath
doaj   +2 more sources

Energy Conditions in a Generalized Second-Order Scalar-Tensor Gravity

Advances in High Energy Physics, 2013
The study of energy conditions has many significant applications in general relativistic and cosmological contexts. This paper explores the energy conditions in the framework of the most general scalar-tensor theory with field equations involving second ...
M. Sharif, Saira Waheed
doaj   +2 more sources

Initial conditions in chaotic inflation with modified gravity [PDF]

EPJ Web of Conferences, 2017
Evolution in chaotic inflationary models begins at a high energy density with semi-classical initial conditions presumably consistent with a universal quantum nature of all the fundamental interactions: each quantum contributes the same amount to the ...
Gorbunov Dmitry
doaj   +2 more sources

Time machines and traversable wormholes in modified theories of gravity

EPJ Web of Conferences, 2013
We review recent work on wormhole geometries in the context of modified theories of gravity, in particular, in f(R) gravity and with a nonminimal curvature-matter coupling, and in the recently proposed hybrid metric-Palatini theory.
Lobo Francisco S.N.
doaj   +2 more sources

Analyzing gravastar structure with the Finch-Skea metric in extended modified symmetric teleparallel gravity

Nuclear Physics B
This study analyzes the physical features of a gravastar within the f(Q,T) gravity framework, where Q is the non-metricity scalar and T is the trace of the energy-momentum tensor.
Iqra Ibrar, M. Sharif
doaj   +2 more sources

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
doaj   +1 more source