Results 81 to 90 of about 26,635,104 (298)
Advanced Materials, EarlyView.Stacked nanoflake assembly (SNA) membranes can oscillate autonomously, offering opportunities for soft actuation and energy harvesting. This work uncovers the physical mechanism behind the sustained oscillation of SNA membranes in gradient humidity and identifies three governing dimensionless parameters, enabling rational design for optimizing SNA ...
Zijing Zhang +5 more
wiley +1 more source
Local gravity constraints and power law f(R) theories [PDF]
Gravitation and Cosmology, 2010 There is a conformal equivalence between power law $f(R)$ theories and scalar field theories in which the scalar degree of freedom evolves under the action of an exponential potential function. In the scalar field representation there is a strong coupling of the scalar field with the matter sector due to the conformal transformation.
openaire +2 more sources
Accelerating cosmology in modified gravity: From convenient F(R) or string-inspired theory to bimetric F(R) gravity [PDF]
International Journal of Geometric Methods in Modern Physics, 2014 We consider modified gravity which may describe the early-time inflation and/or late-time cosmic acceleration of the universe. In particular, we discuss the properties of F(R), F(G), string-inspired and scalar-Einstein–Gauss–Bonnet gravities, including their FRW equations and fluid or scalar-tensor description.
Nojiri, Shin'ichi, Odintsov, Sergei D.
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Advanced Materials, EarlyView.This review examines passive, active, and hybrid liquid manipulation strategies, highlighting hybrid approaches as an emerging route to reconcile energy efficiency with adaptive control. By actively reconstructing passive surfaces to store programmable interfacial energy, hybrid systems enable flexible yet low‐power liquid transport, with perspectives ...
Jiaqi Miao +3 more
wiley +1 more source
Wormholes in exponential f(R, T) gravity
European Physical Journal C: Particles and Fields, 2019 Alternative gravity is nowadays an extremely important tool to address some persistent observational issues, such as the dark sector of the universe. They can also be applied to stellar astrophysics, leading to outcomes one step ahead of those obtained ...
P. H. R. S. Moraes, P. K. Sahoo
doaj +1 more source
On the junction conditions in $f(R)$ -gravity with torsion
, 2018 Junction conditions are discussed within the framework of f(R)-gravity with torsion. After deriving general junction conditions, the cases of coupling to a Dirac field and a spin fluid are explicitly dealt with.
Stefano Vignolo +2 more
core +1 more source
PALATINI APPROACH TO MODIFIED GRAVITY: f(R) THEORIES AND BEYOND [PDF]
International Journal of Modern Physics D, 2011 We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent objects, we review several topics that have been recently studied within this framework. In particular, we provide an
openaire +3 more sources
Anisotropy effects on baryogenesis in f(R) theories of gravity [PDF]
Modern Physics Letters A, 2018 We study the f(R) theory of gravity in an anisotropic metric and its effect on the baryon number-to-entropy ratio. The mechanism of gravitational baryogenesis based on the CPT-violating gravitational interaction between derivative of the Ricci scalar curvature and the baryon-number current is investigated in the context of the f(R) gravity.
A. Aghamohammadi +2 more
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Advanced Materials, EarlyView.Spatiotemporal control over cell behavior within bioprinted constructs remains a key challenge in biofabrication. Volumetric bioprinting using multi‐wavelength light sources permits to activate light‐sensitive intracellular proteins as well as optogenetic gene and protein expression circuits in bioprinted cells, in addition to enabling fast printing of
Davide Ribezzi +14 more
wiley +1 more source
Palatini formulation of the conformally invariant $$f\left( R,L_m\right) $$ f R , L m gravity theory
European Physical Journal C: Particles and Fields, 2022 We investigate the field equations of the conformally invariant models of gravity with curvature-matter coupling, constructed in Weyl geometry, using the Palatini formalism.
Tiberiu Harko, Shahab Shahidi
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