Results 121 to 130 of about 26,635,104 (298)
Designing wormholes in novel power-law f(R): a mathematical approach with a linear equation of state
European Physical Journal C: Particles and FieldsWe consider the inhomogeneous Morris–Thorne wormhole metric with matter tensors characterised by a novel linear equation of state in f(R) gravity. Using the Einstein’s field equations in metric f(R) gravity we model solutions for both wormhole as well as
Subhasis Nalui, Subhra Bhattacharya
doaj +1 more source
Quantum astrometric observables II: time delay in linearized quantum gravity [PDF]
, 2013 A clock synchronization thought experiment is modeled by a diffeomorphism invariant "time delay" observable. In a sense, this observable probes the causal structure of the ambient Lorentzian spacetime. Thus, upon quantization, it is sensitive to the long
Sub String Theory Cosmology and ElemPart +8 more
core +2 more sources
Continuum Mechanics Modeling of Flexible Spring Joints in Surgical Robots
Advanced Robotics Research, EarlyView.A new mechanical model of a tendon‐actuated helical extension spring joint in surgical robots is built using Cosserat rod theory. The model can implicitly handle the unknown contacts between adjacent coils and numerically predict spring shapes from straight to significantly bent under actuation forces.
Botian Sun +3 more
wiley +1 more source
Evolution of compact stars and dark dynamical variables
European Physical Journal C: Particles and Fields, 2017 This work aims to explore the dark dynamical effects of the f(R, T) modified gravity theory on the dynamics of a compact celestial star. We have taken the interior geometry of a spherical star which is filled with an imperfect fluid distribution.
M. Z. Bhatti, Z. Yousaf, M. Ilyas
doaj +1 more source
Advanced Robotics Research, EarlyView.Pak Biawak, a necrobot, embodies an unusual fusion of biology and robotics. Designed to repurpose natural structures after death, it challenges conventional boundaries between nature and engineering. Its movements are precise yet unsettling, raising questions about sustainability, ethics, and the untapped potential of biointegrated machines.
Leo Foulds +2 more
wiley +1 more source
Phantom-like behavior in f(R)-gravity [PDF]
, 2009 We investigate possible realization of the phantom-like behavior in the framework of f(R)-gravity models where there are no phantom fields in the matter sector of the theory.
Azizi, Tahereh, Nozari, Kourosh
core +1 more source
f(R)-theories of gravity and gravitational baryogenesis
Journal of Physics: Conference Series, 2007 The mechanism for generating the baryon asymmetry in the Universe is discussed in the framework of f(R)-theories of gravity. The gravitational baryogenesis, based on the coupling between the Ricci scalar curvature R and the baryon current, allows to determine the form of gravity Lagrangian, i.e. (R) ~ Rn.
LAMBIASE, Gaetano, SCARPETTA, Gaetano
openaire +1 more source
Advanced Robotics Research, EarlyView.Permanent magnet putty (PMP) integrates high‐coercivity NdFeB particles with a dynamic polyborosiloxane–Ecoflex matrix, achieving rapid self‐healing (90% mechanical recovery in 10 s) and magnetic recovery within 20 min. With twice the sensitivity of commercial putties, PMP enables precise 5–30 N force detection and discrimination between pressing and ...
Ruotong Zhao +5 more
wiley +1 more source
A complete cosmological scenario from $$f(R,T^{\phi })$$ f ( R , T ϕ ) gravity theory
, 2016 Recent elaborated by Harko et al., the f(R, T) theories of gravity allow one to contemplate an optimistic alternative to dark energy, for which R and T stand for the Ricci scalar and the trace of the energy-momentum tensor, respectively.
P. H. R. S. Moraes, J. R. L. Santos
core +1 more source
Origami‐Inspired Structural Design for Aquatic‐Terrestrial Amphibious Robots
Advanced Robotics Research, EarlyView.This work presents a lightweight amphibious origami robot actuated by a single shape memory alloy wire. A rigid foldable origami structure with displacement amplification enables efficient terrestrial crawling and aquatic swimming. The addition of fan‐shaped units allows controllable turning in both environments.
Weiqi Liu +5 more
wiley +1 more source