Results 121 to 130 of about 6,479 (312)
Universal spacetimes in four dimensions
Journal of High Energy Physics, 2017 Universal spacetimes are exact solutions to all higher-order theories of gravity. We study these spacetimes in four dimensions and provide necessary and sufficient conditions for universality for all Petrov types except of type II.
S. Hervik, V. Pravda, A. Pravdová
doaj +1 more source
Developments in noncommutative differential geometry [PDF]
, 2002 One of the great outstanding problems of theoretical physics is the quantisation of gravity, and an associated description of quantum spacetime. It is often argued that, at short distances, the manifold structure of spacetime breaks down and is replaced ...
Hale, Mark
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Advanced Intelligent Systems, Volume 7, Issue 3, March 2025.This review aims to provide a broad understanding for interdisciplinary researchers in engineering and clinical applications. It addresses the development and control of magnetic actuation systems (MASs) in clinical surgeries and their revolutionary effects in multiple clinical applications.
Yingxin Huo +3 more
wiley +1 more source
Redirecting Excited‐State Proton Transfer Through Supramolecular Polymerization in Nanoconfinement
Angewandte Chemie, EarlyView.Supramolecular confinement redirects the excited‐state proton transfer pathway of an amphoteric emitter. In water, the molecule undergoes ESPD, whereas co‐assembly with γ‐cyclodextrin forms nanotubes that template slip‐stacked emitter pairs and enable ESIMPT. Structural and photophysical characterization of the assemblies shows that the preorganization
Luis C. Pantaleone +8 more
wiley +2 more sources
Memory, Penrose limits and the geometry of gravitational shockwaves and gyratons
Journal of High Energy Physics, 2018 The geometric description of gravitational memory for strong gravitational waves is developed, with particular focus on shockwaves and their spinning analogues, gyratons.
Graham M. Shore
doaj +1 more source
Advanced Intelligent Systems, Volume 7, Issue 3, March 2025.Magnetic soft robots offer promise in biomedicine due to their wireless actuation and rapid response, but current fabrication methods are complex and have limited cellular compatibility. A new, contactless bioassembly strategy using hydrodynamic instabilities is introduced, enabling customizable, centimeter‐scale robots.
Wei Gao +5 more
wiley +1 more source
On the ‘simple’ form of the gravitational action and the self-interacting graviton
Journal of High Energy Physics, 2017 The so-called ΓΓ-form of the gravitational Lagrangian, long known to provide its most compact expression as well as the most efficient generation of the graviton vertices, is taken as the starting point for discussing General Relativity as a theory of ...
E. T. Tomboulis
doaj +1 more source
Take a Ride on a Time Machine [PDF]
, 2003 We discuss the possibility to build and operate a time machine, a device that produces closed timelike curves (CTCs). We specify the spacetime structure needed to implement a time machine and assess attempted no-go results against time machines in ...
Wuthrich, Christian +2 more
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EMG‐Driven Telemetry and Inference System for Fish: Pose Reconstruction and Flow Sensing
Advanced Intelligent Systems, EarlyView.This work introduces an electromyography (EMG)‐driven telemetry framework that reconstructs body pose and infers hydrodynamic conditions in freely swimming fish. A custom 16‐channel archival system records intramuscular EMG, enabling deep‐learning models to decode joint kinematics, classify flow regimes, and reveal channel‐efficient sensing strategies.
Rahdar Hussain Afridi +7 more
wiley +1 more source
Virtual Gravity and the Duality of Reality [PDF]
, 2003 It is shown that a hypothesis about gravity having a virtual cause implies there are two primary reference frames, a reality and a functional virtual reality and an equivalence principle relating the two is postulated.
Harokopos, E, Harokopos, Efthimios
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