Results 21 to 30 of about 26,635,104 (298)
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
core +4 more sources
Thermodynamics of f(R) theories of gravity [PDF]
Journal of Cosmology and Astroparticle Physics, 2020 13 pages, 11 figures.
Peralta, C. D., Jorás, S. E.
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On f(R) gravity in scalar–tensor theories [PDF]
International Journal of Geometric Methods in Modern Physics, 2017 We study [Formula: see text] gravity models in the language of scalar–tensor (ST) theories. The correspondence between [Formula: see text] gravity and ST theories is revisited since [Formula: see text] gravity is a subclass of Brans–Dicke models, with a vanishing coupling constant ([Formula: see text]).
Ntahompagaze, Joseph +2 more
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On wormhole throats in f (R) gravity theory [PDF]
General Relativity and Gravitation, 2012 36 pages, 35 figures. Updated version contains some stylistic improvements and added comments. Some typographical errors corrected. More references added.
DeBenedictis, Andrew, Horvat, Dubravko
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Inflation from f(R) theories in gravity’s rainbow [PDF]
The European Physical Journal C, 2020 AbstractIn this work, we study the f(R) models of inflation in the context of gravity’s rainbow theory. We choose three types of f(R) models: $$f(R)=R+\alpha (R/M)^{n},\,f(R)=R+\alpha R^{2}+\beta R^{2}\log (R/M^{2})$$ f ( R )
Areef Waeming, Phongpichit Channuie
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Metric-affine f(R) theories of gravity [PDF]
Annals of Physics, 2007 General Relativity assumes that spacetime is fully described by the metric alone. An alternative is the so called Palatini formalism where the metric and the connections are taken as independent quantities. The metric-affine theory of gravity has attracted considerable attention recently, since it was shown that within this framework some cosmological ...
THOMAS P. SOTIRIOU, Liberati, Stefano
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Consequences of $$f(R)$$ f ( R ) theories of gravity on gravitational leptogenesis [PDF]
General Relativity and Gravitation, 2013 f(R)-theories of gravity are reviewed in the framework of the matter-antimatter asymmetry in the Universe. The asymmetry is generated by the gravitational coupling of heavy (Majorana) neutrinos with the Ricci scalar curvature. In order that the mechanism works, a time varying non-zero Ricci curvature is necessary.
LAMBIASE, Gaetano +2 more
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Kinematics and dynamics off(R) theories of gravity [PDF]
General Relativity and Gravitation, 1996 13 pages, latex, to appear in ...
Rippl, Steve +3 more
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Viability of Noether Symmetry of F(R) Theory of Gravity [PDF]
International Journal of Theoretical Physics, 2012 Canonization of F(R) theory of gravity to explore Noether symmetry is performed treating R - 6(\frac{\ddot a}{a} + \frac{\dot a^2}{a^2} + \frac{k}{a^2}) = 0 as a constraint of the theory in Robertson-Walker space-time, which implies that R is taken as an auxiliary variable.
Sarkar, Kaushik +3 more
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Stochastic Entanglement of Deterministic Origami Tentacles For Robust Robotic Grasping. [PDF]
Adv Sci (Weinh)This study introduces an origami tentacle gripper to robustly grasp objects‐in air, underwater, and even in orbital space‐by exploiting a synergy between local, deterministic deformation programming and global, stochastic entanglements. A single origami tentacle can be designed to coil with a simple tendon pull.
Boron A +4 more
europepmc +2 more sources