Results 101 to 110 of about 22,331 (301)
Quantum Gravity: Motivations and Alternatives [PDF]
, 2009 The mutual conceptual incompatibility between General Relativity and Quantum Mechanics / Quantum Field Theory is generally seen as the most essential motivation for the development of a theory of Quantum Gravity.
Hedrich, Reiner
core +1 more source
On Rastall gravity formulation as a $f(R,\mathcal{L}_m)$ and a $f(R,T)$ theory
, 2023 Rastall introduced a stress-energy tensor whose divergence is proportional to the gradient of the Ricci scalar. This proposal leads to a change in the form of the field equations of General Relativity, but it preserves the number of degrees of freedom ...
Rodrigues, Davi C. +2 more
core +1 more source
Advanced Materials Technologies, EarlyView.A flexible pressure sensor utilizing a 3D dual‐pore polyurethane structure is developed to overcome the intrinsic trade‐off between sensitivity and linearity. By inducing sequential buckling through distinct pore sizes and shapes, the device achieves highly linear and sensitive responses across a wide pressure range.
Jae Yeong Jang, Jaemin Choi, Young Jung
wiley +1 more source
The impact of $$f(R,\Sigma ,T)$$ f ( R , Σ , T ) gravity on strange star structure
European Physical Journal C: Particles and FieldsThis research paper explores the structure of hypothetical compact stars, known as strange stars, within the framework of a novel modified theory of gravity called $$f(R,\Sigma ,T)$$ f ( R , Σ , T ) gravity.
M. A. Bakry, A. Eid, Tahia F. Dabash
doaj +1 more source
The Polarizations of Gravitational Waves
Universe, 2018 The gravitational wave provides a new method to examine General Relativity and its alternatives in the high speed, strong field regime. Alternative theories of gravity generally predict more polarizations than General Relativity, so it is important to ...
Yungui Gong, Shaoqi Hou
doaj +1 more source
In this paper, our objective is to explore a time-machine space-time formulated in general relativity, as introduced by Li (Phys. Rev. D {\bf 59}, 084016 (1999)), within the context of modified gravity theories.
Ahmed, F. +2 more
core +1 more source
Hard‐Magnetic Soft Millirobots in Underactuated Systems
Advanced Robotics Research, EarlyView.This review provides a comprehensive overview of hard‐magnetic soft millirobots in underactuated systems. It examines key advances in structural design, physics‐informed modeling, and control strategies, while highlighting the interplay among these domains.
Qiong Wang +4 more
wiley +1 more source
Reconstructing $f(R,T)$ gravity from holographic dark energy
, 2012 We consider cosmological scenarios based on $f(R,T)$ theories of gravity ($R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor) and numerically reconstruct the function $f(R,T)$ which is able to reproduce the same expansion history ...
M. J. S. Houndjo, PIATTELLA O
core +1 more source
Higher-dimensional inhomogeneous perfect fluid collapse in f(R) gravity
European Physical Journal C: Particles and Fields, 2017 This paper is about the $$n+2$$ n + 2 -dimensional gravitational contraction of an inhomogeneous fluid without heat flux in the framework of a f(R) metric theory of gravity.
G. Abbas +3 more
doaj +1 more source
Possible antigravity regions in F(R)F(R) theory? [PDF]
, 2014 We construct an F(R)F(R) gravity theory corresponding to the Weyl invariant two scalar field theory. We investigate whether such F(R)F(R) gravity can have the antigravity regions where the Weyl curvature invariant does not diverge at the Big Bang and Big
Nojiri, Shin'ichi +5 more
core +1 more source