Results 61 to 70 of about 22,331 (301)
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
Rapid Fabrication of Self‐Propelled and Steerable Magnetic Microcatheters for Precision Medicine
Advanced Materials, EarlyView.A rapid Joule heating fabrication method for the production of self‐propelling, adaptive microcatheters, with tunable stiffness and integrated microfluidic channels is presented. Demonstrated through three microrobotic designs, including a steerable guiding catheter, an untethered wave‐crawling TubeBot, and a distal‐end propelled microcatheter, it was ...
Zhi Chen +5 more
wiley +1 more source
Stellar equilibrium configurations of white dwarfs in the f(R, T) gravity
European Physical Journal C: Particles and Fields, 2017 In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, namely, f(R, T) gravity, for which R and T stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.
G. A. Carvalho +6 more
doaj +1 more source
SOME REMARKS ON f(R) THEORIES OF GRAVITY
International Journal of Modern Physics: Conference Series, 2011 In this paper, I make a brief review of f(R) theories and their shortcomings — with some emphasis on the latter. I constrain myself to f(R) theories, the current acceleration of the (homegeneous) universe and the metric formalism (except at the very end).
openaire +2 more sources
The equivalence and/or the effacing principle in f(R) theories of gravity
, 2022 The Einstein–Hilbert action of the general theory of relativity (GR) is the integral of the scalar curvature R. It is a theory that is drawn from the Equivalence principle and has predictions that come out as a consequence of the principle, in observables.
openaire +2 more sources
Advanced Materials, EarlyView.Harnessing the synergistic interplay of supramolecular self‐assembly, under macromolecular crowding conditions, and enzymatic‐mediated covalent crosslinking toward a stable protein‐based G‐quadruplex‐derived supramolecular bioink. This bioinspired strategy enables the biofabrication of complex and tunable ECM‐mimetic constructs, providing a platform ...
Vera Sousa +6 more
wiley +1 more source
Axially symmetric solutions in Ricci-inverse modified gravity
European Physical Journal C: Particles and FieldsWe investigate a family of axial symmetry solution constructed in general relativity (GR) within the framework of Ricci-inverse (RI) gravity theory. In GR, these solutions admitted closed time-like curves at an instant of time from an initial spacelike ...
F. Ahmed +2 more
doaj +1 more source
Emergence of running vacuum energy in f(R, T) gravity : Observational constraints
Physics Letters BIn this work, we present a new analysis for f(R, T) gravity by exploring the energy momentum tensor. We demonstrate that f(R, T) gravity with the form f(R,T)=R+2κ2λT−2Λ is equivalent to Running Vacuum Energy (RVE), which interacts with the components of ...
Ahmed Errahmani +4 more
doaj +1 more source
Strange stars in f(R) theories of gravity in the Palatini formalism [PDF]
General Relativity and Gravitation, 2017 10 pages, 2 ...
openaire +3 more sources
Miniature Soft Robot With Magnetically Reprogrammable Surgical Functions
Advanced Materials, EarlyView.Miniature soft robots have great prospects to revolutionize minimally invasive treatments. Here we present a miniature soft robot, which can be reprogrammed to perform five surgical functionalities with six‐degrees‐of‐freedom motions. This soft robot can prospectively make minimally invasive surgery considerably safer and painless, and enable ...
Chelsea Shan Xian Ng +4 more
wiley +1 more source