Results 61 to 70 of about 8,019 (262)

The gravitational energy-momentum pseudo-tensor of conformally invariant theories of gravity

Journal of High Energy Physics
We construct the gravitational energy-momentum pseudo-tensor of up to fourth-order conformally invariant theories of gravity. Then we linearize the pseudo-tensor and use its average over a macroscopic region to find the energy and momentum carried by the
F.F. Faria
doaj   +1 more source

Partonic angular momentum in the nucleon's chiral periphery

Physics Letters B, 2019
We study the nucleon's partonic angular momentum (AM) content at peripheral transverse distances b=O(Mπ−1), where the structure is governed by chiral dynamics.
C. Granados, C. Weiss
doaj   +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, Zixuan Zhang, Bingyan Li, Junkai Wang, Hongcheng Gu   +4 more
wiley   +1 more source

Self-gravitating field configurations: The role of the energy–momentum trace

Physics Letters B, 2014
Static spherically-symmetric matter distributions whose energy–momentum tensor is characterized by a non-negative trace are studied analytically within the framework of general relativity.
Shahar Hod
doaj   +1 more source

Multimodal Locomotion in Insect‐Inspired Microrobots: A Review of Strategies for Aerial, Surface, Aquatic, and Interfacial Motion

Advanced Robotics Research, EarlyView.
This review identifies key design considerations for insect‐inspired microrobots capable of multimodal locomotion. To draw inspiration, biological and robotic strategies for moving in air, on water surfaces, and underwater are examined, along with approaches for crossing the air–water interface.
Mija Jovchevska, Kaushik Jayaram, Nicole Xu   +2 more
wiley   +1 more source

Finite temperature fermionic condensate and energy–momentum tensor in cosmic string spacetime

European Physical Journal C: Particles and Fields
Here we analyze the expectation value of the fermionic condensate and the energy–momentum tensor associated with a massive charged fermionic quantum field with a nonzero chemical potential propagating in a magnetic-flux-carrying cosmic string in thermal ...
W. Oliveira dos Santos, E. R. Bezerra de Mello   +1 more
doaj   +1 more source

Gravitization equation and zero energy momentum tensor theorem with cancellation law in gravitational quantum field theory

Physics Letters B
We investigate the essential properties of gravitational quantum field theory (GQFT) based on spin gauge symmetry, using the general theory of quantum electrodynamics as an example.
Yue-Liang Wu
doaj   +1 more source

Waveguide Photoactuators: Materials, Fabrication, and Applications

Advanced Robotics Research, EarlyView.
Waveguide photoactuators convert guided light into mechanical motion. Their tethered‐flexible design enables minimally invasive surgery and confined‐space robotics. This review aims to guide materials selection, device design, and system integration, accelerating the transition of waveguide photoactuators from laboratory prototypes to versatile ...
Minjie Xi, Hemin Pan, Yang Zong, Yongfeng Mei, Jizhai Cui   +4 more
wiley   +1 more source

On scalaron decay via the trace of energy-momentum tensor

Journal of High Energy Physics, 2019
In some inflation scenarios such as R 2 inflation, a gravitational scalar degrees of freedom called scalaron is identified as inflaton. Scalaron linearly couples to matter via the trace of energy-momentum tensor.
Ayuki Kamada
doaj   +1 more source

The four-point correlation function of the energy-momentum tensor in the free conformal field theory of a scalar field

European Physical Journal C: Particles and Fields, 2020
We present an explicit momentum space computation of the four-point function of the energy-momentum tensor in 4 spacetime dimensions for the free and conformally invariant theory of a scalar field.
Mirko Serino
doaj   +1 more source