Results 91 to 100 of about 540,486 (189)
The Dilaton and Modified Gravity
, 2010 We consider the dilaton in the strong string coupling limit and elaborate on the original idea of Damour and Polyakov whereby the dilaton coupling to matter has a minimum with a vanishing value at finite field-value.
Anne-Christine Davis +8 more
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Wave propagation in modified gravity
Physical Review D, 2016 We investigate the propagation of scalar waves induced by matter sources in the context of scalar-tensor theories of gravity which include screening mechanisms for the scalar degree of freedom. The usual approach when studying these theories in the non-linear regime of cosmological perturbations is based on the assumption that scalar waves travel at ...
Lindroos, Jan Ø. +2 more
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European Physical Journal C: Particles and Fields, 2020 The strong gravitational field near massive blackhole is an interesting regime to test General Relativity (GR) and modified gravity theories. The knowledge of spacetime metric around a blackhole is a primary step for such tests.
Utkarsh Kumar +2 more
doaj +1 more source
Horizon entropy in modified gravity [PDF]
Physical Review D, 2005 We present an observation about the proposal that four-dimensional modification of general relativity may explain the observed cosmic acceleration today. Assuming that the thermodynamical nature of gravity theory continues to hold in modified gravity theories, we derive the modified horizon entropy formula from the modified Friedmann equation. We argue
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New classes of modified teleparallel gravity models
Physics Letters B, 2017 New classes of modified teleparallel theories of gravity are introduced. The action of this theory is constructed to be a function of the irreducible parts of torsion f(Tax,Tten,Tvec), where Tax,Tten and Tvec are squares of the axial, tensor and vector ...
Sebastian Bahamonde +2 more
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Quantum gravity effect on the Hawking radiation of charged rotating BTZ black hole
, 2018 In this study, the quantum gravity effect on the tunnelling radiation of charged massive spin-0 scalar particle from 2+1 dimensional charged rotating Banados-Teitelboim-Zanelli (BTZ) black hole is looked into by using the Hamilton-Jacobi approach.
Gecim, Ganim, Sucu, Yusuf
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Modified gravity makes galaxies brighter
Physical Review D, 2012 We investigate the effect of modifed gravity with screening mechanisms, such as the chameleon or symmetron models, upon the structure of main sequence stars. We find that unscreened stars can be significantly more luminous and ephemeral than their screened doppelgangers.
Davis, Anne-Christine +3 more
openaire +4 more sources
, 2013 The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is not the correct description of gravity when we consider distances of the order of the present horizon of the ...
openaire +2 more sources
Pure-Connection Gravity and Anisotropic Singularities
Universe, 2018 In four space-time dimensions, there exists a special infinite-parameter family of chiral modified gravity theories. They are most properly described by a connection field, with space-time metric being a secondary and derived concept.
Kirill Krasnov, Yuri Shtanov
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Nonlocal Gravity: Modified Poisson's Equation
, 2012 The recent nonlocal generalization of Einstein's theory of gravitation reduces in the Newtonian regime to a nonlocal and nonlinear modification of Poisson's equation of Newtonian gravity.
B. Mashhoon +5 more
core +1 more source