Results 51 to 60 of about 5,915,931 (293)

Emergent gravity from vanishing energy-momentum tensor

Journal of High Energy Physics, 2017
A constraint of vanishing energy-momentum tensor is motivated by a variety of perspectives on quantum gravity. We demonstrate in a concrete example how this constraint leads to a metric-independent theory in which quantum gravity emerges as a ...
Christopher D. Carone, Joshua Erlich, Diana Vaman   +2 more
doaj   +1 more source

Rational Tuning of Hygroscopic Oscillation of Stacked Nanoflake Assemblies for Continuous Ambient Energy Harvesting

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, Jimin Fu, Gesa Zhang, Zhihua Liang, Boxun Zhang, Haimin Yao   +5 more
wiley   +1 more source

The electromagnetic energy–momentum tensor [PDF]

, 2022
We clarify the relation between canonical and metric energy-momentum tensors. In particular, we show that a natural definition arises from Noether's Theorem which directly leads to a symmetric and gauge invariant tensor for electromagnetic field theories
Gamboa Saraví, Ricardo Enrique
core  

Bioinspired Adaptive Surfaces for Intelligent Liquid Manipulation: Progressing From Passive and Active to Hybrid Strategies

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, Yiyuan Zhang, Liqiu Wang, Alan C. H. Tsang   +3 more
wiley   +1 more source

Non-minimal energy–momentum squared gravity

European Physical Journal C: Particles and Fields, 2021
We consider a gravitational theory with an additional non-minimal coupling between baryonic matter fields and geometry. The coupling is second order in the energy momentum tensor and can be seen as a generalization of the energy–momentum squared gravity ...
Shahab Shahidi
doaj   +1 more source

Above Room Temperature Ferroelectricity in Epitaxially Strained KTaO3

Advanced Materials, EarlyView.
Through precise epitaxial engineering, the cubic and paraelectric KTaO3${\rm KTaO}_3$ is transformed into a robust ferroelectric. By leveraging lattice‐mismatched substrates to apply controlled epitaxial strain, a stable ferroelectric ground‐state is achieved with a transition temperature as high as 475 K, establishing KTaO3${\rm KTaO}_3$ as a highly ...
Tobias Schwaigert, Salva Salmani‐Rezaie, Sankalpa Hazra, Utkarsh Saha, Maya Ramesh, Aiden Ross, Betül Pamuk, Long‐Qing Chen, David A. Muller, Darrell G. Schlom, Venkatraman Gopalan, Kaveh Ahadi   +11 more
wiley   +1 more source

Non-relativistic geometry of holographic screens

Journal of High Energy Physics, 2017
We propose that the intrinsic geometry of holographic screens should be described by the Newton-Cartan geometry. As a test of this proposal, we show that the evolution equations of the screen can be written in a covariant form in terms of a stress tensor,
Mudassir Moosa
doaj   +1 more source

Parity‐Dependent THz Harmonic Generation in Electrically Pumped Micro‐Lasers Exploiting Topological Insulator–Metamaterial Gratings

Advanced Materials, EarlyView.
Topological insulator–metamaterials integrated with electrically driven terahertz quantum cascade lasers enable parity‐dependent harmonic generation. Bulk‐dominated Bi2Se3 favors third‐harmonic emission at 9.96 THz, whereas topological‐surface‐state‐dominated Bi2Se3, Bi2Te3, and (Bi,Sb)2Te3 generate strong second harmonics near 6.5 THz.
Alessandra Di Gaspare, Craig S. Knox, Ahmet Yagmur, Sara Ghayeb Zamharir, Lianhe Li, Satoshi Sasaki, A. Giles Davies, Edmund H. Linfield, Joshua R. Freeman, Miriam S. Vitiello   +9 more
wiley   +1 more source

Upscaling Pulsed Laser Fragmentation in Liquids by Advanced Free‐Flow Setups

Advanced Materials Technologies, EarlyView.
Advanced flow setups providing thin colloid films are introduced to upscale pulsed laser fragmentation in liquids for sustainable nanoparticle synthesis. Their potential is demonstrated by yielding remarkably small ZnO nanoparticles of <7 nm. Numerical simulations complement the study, revealing that the superior performance can be attributed to ...
Jan Lino Kricke, Zongwen Fu, Sebastian Burgmann, Uwe Janoske, Carlos Doñate‐Buendía, Bilal Gökce   +5 more
wiley   +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