Results 51 to 60 of about 537,661 (283)
Matter Instability in Theories with Modified Induced Gravity
Advances in High Energy Physics, 2012 Matter stability is a necessary condition to have a cosmologically viable model. Modified gravity in the spirit of f(R) theories suffers from matter instability in some subdomains of the model parameter space.
Kourosh Nozari, Faeze Kiani
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Generalized gravity from modified DFT
Journal of High Energy Physics, 2017 Recently, generalized equations of type IIB supergravity have been derived from the requirement of classical kappa-symmetry of type IIB superstring theory in the Green-Schwarz formulation.
Yuho Sakatani +2 more
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Classical and Quantum GravityAbstract A complete canonical formulation of general covariance makes it possible to construct new modified theories of gravity that are not of higher-curvature form, as shown here in a spherically symmetric setting. The usual uniqueness theorems are evaded by using a crucial and novel ingredient, allowing for fundamental fields of ...
Martin Bojowald, Erick I Duque
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Born–Infeld-type modified gravity [PDF]
International Journal of Geometric Methods in Modern Physics, 2019 We propose and investigate the modified Born–Infeld-type gravity model with the function [Formula: see text]. At different values of the dimensionless parameter [Formula: see text], the action is converted into some models including general relativity ([Formula: see text]), the Starobinsky model ([Formula: see text]), the exponential model of gravity (
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Generalized Chern-Simons Modified Gravity in First-Order Formalism
, 2012 We propose a generalization of Chern-Simons (CS) modified gravity in first-order formalism. CS modified gravity action has a term that comes from the chiral anomaly which is Pontryagin invariant.
A Torres-Gomez +25 more
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Charged gravastars in modified gravity [PDF]
Physical Review D, 2019 23 pages, 6 figures, final version to appear in Physical Review ...
Yousaf, Z. +3 more
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Modified gravity one-loop partition function
European Physical Journal C: Particles and Fields, 2018 The one-loop partition function of the $$f(R,R_{\mu \nu }R^{\mu \nu })$$ f(R,RμνRμν) gravity theory is obtained around $$\hbox {AdS}_4$$ AdS4 background.
Shahab Shahidi +3 more
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, 2018 We present a new parameterization for the equation of state (EoS) $ _X=P_X/ _X$, which can reproduce a $f(R)$-like evolution with a precision between $[0.5\%-0.8\%]$ over the numerical solutions. Also, our proposal can render a variety of popular $f(R)$ models that are considered as viable candidates for the cosmic late time acceleration.
Jaime, Luisa G. +2 more
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GRAVITY FROM A MODIFIED COMMUTATOR [PDF]
International Journal of Modern Physics D, 2005 We show that a suitably chosen position-momentum commutator can elegantly describe many features of gravity, including the IR/UV correspondence and dimensional reduction ("holography"). Using the most simplistic example based on dimensional analysis of black holes, we construct a commutator which qualitatively exhibits these novel properties of ...
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Cell surface interactome analysis identifies TSPAN4 as a negative regulator of PD‐L1 in melanoma
Molecular Oncology, EarlyView.Using cell surface proximity biotinylation, we identified tetraspanin TSPAN4 within the PD‐L1 interactome of melanoma cells. TSPAN4 negatively regulates PD‐L1 expression and lateral mobility by limiting its interaction with CMTM6 and promoting PD‐L1 degradation.
Guus A. Franken +7 more
wiley +1 more source