Results 11 to 20 of about 166,028,825 (289)
A class of minimally modified gravity theories [PDF]
Journal of Cosmology and Astroparticle Physics, 2017 We investigate the Hamiltonian structure of a class of gravitational theories whose actions are linear in the lapse function. We derive the necessary and sufficient condition for a theory in this class to have two or less local physical degrees of freedom.
Lin, Chunshan, Mukohyama, Shinji
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Modified Theories of Gravity [PDF]
, 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 ...
Fluvio Sbisa, F. Sbisa', Sbisa, Fulvio
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The viability of modified gravity theories [PDF]
, 2009 PhDThis thesis studies the viability of classes of modified gravity (MG) theories based on generalisations of the Einstein-Hilbert action. Particular emphasis is given to f(R) theories in both the metric and Palatini formalisms, scalar-tensor theories ...
Uddin, Kotub
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Maximum force in modified gravity theories [PDF]
Physical Review D, 2020 10 pages, no figures, section on power law gravity dropped, additions to conclusions, The paper is dedicated to the fond memory of one of the authors, John Barrow who passed away on 26 Sept 2020 - Naresh Dadhich ...
John D. Barrow, Naresh Dadhich
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THERMODYNAMICS IN MODIFIED GRAVITY THEORIES [PDF]
International Journal of Modern Physics D, 2011 We demonstrate that there exists an equilibrium description of thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density f(R,ϕ,X), where R is the Ricci scalar and X is the kinetic energy of a scalar field ϕ.
Bamba, Kazuharu +2 more
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Modified Theories of Gravity and Cosmological Applications [PDF]
, 2023 This reprint focuses on recent aspects of gravitational theory and cosmology. It contains subjects of particular interest for modified gravity theories and applications to cosmology, special attention is given to Einstein–Gauss–Bonnet, f(R)-gravity ...
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A Modified Gravity Theory: Null Aether* [PDF]
Communications in Theoretical Physics, 2019 Abstract General quantum gravity arguments predict that Lorentz symmetry might not hold exactly in nature. This has motivated much interest in Lorentz breaking gravity theories recently. Among such models are vector-tensor theories with preferred direction established at every point of spacetime by a fixed-norm ...
Gurses, Metin, Senturk, Cetin
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Accelerating universe in modified theories of gravity [PDF]
Physical Review D, 2009 23 pages, 11 figs.
Paul, B. C., Debnath, P. S., Ghose, S.
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A New Approach to Modifying Theories of Gravity [PDF]
Foundations of Physics, 2013 9 pages, conservation equation discussion revised, Kasner type solutions ...
Böhmer, Christian G., Tamanini, Nicola
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Universe, 2022 Scalar Tensor Vector Gravity (STVG) or MOdified Gravity (MOG) is a metric theory of gravity with dynamical scalar fields and a massive vector field introduced in addition to the metric tensor.
Sreekanth Harikumar
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