Results 61 to 70 of about 166,017,541 (302)

Large Quantum Gravity Effects: Unforeseen Limitations of the Classical Theory [PDF]

Physical Review Letters, 1996
3-dimensional gravity coupled to Maxwell (or Klein-Gordon) fields is exactly soluble under the assumption of axi-symmetry. The solution is used to probe several quantum gravity issues. In particular, it is shown that the quantum fluctuations in the geometry are large unless the number and frequency of photons satisfy the inequality $\N(\hbar Gω)^2 <&
openaire   +3 more sources

A Two‐Stage Questionnaire and Actigraphy Screening for iRBD in a Multicenter Retrospective Cohort

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Isolated rapid‐eye‐movement sleep behavior disorder is a prodromal marker of synucleinopathies. However, most cases remain undiagnosed due to the insufficient predictive value of questionnaires and limited access to confirmatory video‐polysomnography. We assessed a two‐stage screening strategy combining a brief questionnaire on rapid‐
Caleb A. Massimi, Giorgio Ricciardiello Mejia, Andre Metzger, Kang Hyun Ryu, Salonee Marwaha, Eva Grzegorczyk, Li Zhou, Eliana Jacobs, Boris Gilyadov, Claudia Kunney, Liqhwa Ncube, Ankit Parekh, Emmanuel Mignot, Fanny M. Elahi, Joseph Winer, Kathleen Poston, Andreas Brink‐Kjaer, Emmanuel H. During   +17 more
wiley   +1 more source

Kerr-Schild double copy for Kundt spacetimes of any dimension

Journal of High Energy Physics
We show that vacuum type N Kundt spacetimes in an arbitrary dimension admit a Kerr-Schild (KS) double copy. This is mostly done in a coordinate-independent way using the higher-dimensional Newman-Penrose formalism.
Marcello Ortaggio, Vojtěch Pravda, Alena Pravdová   +2 more
doaj   +1 more source

Massive spin-2 scattering and asymptotic superluminality

Journal of High Energy Physics, 2018
We place model-independent constraints on theories of massive spin-2 particles by considering the positivity of the phase shift in eikonal scattering. The phase shift is an asymptotic S-matrix observable, related to the time delay/advance experienced by ...
Kurt Hinterbichler, Austin Joyce, Rachel A. Rosen   +2 more
doaj   +1 more source

Null infinity as an open Hamiltonian system

Journal of High Energy Physics, 2021
When a system emits gravitational radiation, the Bondi mass decreases. If the Bondi energy is Hamiltonian, it can thus only be a time-dependent Hamiltonian. In this paper, we show that the Bondi energy can be understood as a time-dependent Hamiltonian on
Wolfgang Wieland
doaj   +1 more source

Observer‐Based Adaptive Event‐Triggered Tracking Control for Fuzzy TS Systems With Premise Mismatch

International Journal of Adaptive Control and Signal Processing, EarlyView.
This paper presents an adaptive logistic event‐triggered observer‐based tracking controller for Takagi‐Sugeno fuzzy systems under constrained inputs and network delays. Leveraging a hybrid LMI and Secretary Bird Optimization approach, this strategy significantly minimizes communication overhead and computational burden while ensuring optimal reference ...
Oussama Djadane, Salama Makni, Mourad Kchaou, Ahmed El Hajjaji   +3 more
wiley   +1 more source

Corners of gravity: the case of gravity as a constrained BF theory

Journal of High Energy Physics, 2021
Following recent works on corner charges we investigate the boundary structure in the case of the theory of gravity formulated as a constrained BF theory.
Remigiusz Durka, Jerzy Kowalski-Glikman
doaj   +1 more source

A proposal for a Bohmian ontology of quantum gravity [PDF]

, 2013
The paper shows how the Bohmian approach to quantum physics can be applied to develop a clear and coherent ontology of non-perturbative quantum gravity.
Michael Esfeldy, Vassallo, Antonio, Antonio Vassallo, Michael Esfeld, Esfeld, Michael, Vassallo, A., Antonio Vassalloyz, Esfeld, M.   +7 more
core   +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

PhD thesis : Compact objects in modified theories of gravity [PDF]

, 2022
The formulation of General Relativity by Albert Einstein in 1915 revolutionised our understanding of the gravitational interaction. However, despite its tremendous successes, this theory struggle to explain certain important phenomena such as the ...
Ducobu, Ludovic
core   +1 more source