Results 81 to 90 of about 3,823,424 (306)

Gravity and Gauge [PDF]

open access: yes, 2012
Philosophers of physics and physicists have long been intrigued by the analogies and disanalogies between gravitational theories and (Yang-Mills-type) gauge theories.
Teh, Nicholas
core  

Quantum reduced loop gravity: Semiclassical limit [PDF]

open access: yesPhysical Review D, 2014
We discuss the semiclassical limit of Quantum Reduced Loop Gravity, a recently proposed model to address the quantum dynamics of the early Universe. We apply the techniques developed in full Loop Quantum Gravity to define the semiclassical states in the kinematical Hilbert space and evaluating the expectation value of the euclidean scalar constraint we
ALESCI, Emanuele, Cianfrani F.
openaire   +2 more sources

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

open access: yesInternational 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   +3 more
wiley   +1 more source

Renormalization group flow of f(R)-gravity [PDF]

open access: yes, 2008
We use the functional renormalization group equation for quantum gravity to construct a non-perturbative flow equation for modified gravity theories of the form $S = \int d^dx \sqrt{g} f(R)$.
Afd Theoretical Physics (ITF)   +4 more
core  

Integrable deformations of dimensionally reduced gravity

open access: yesJournal of High Energy Physics
Dimensional reduction of gravity theories to D = 2 along commuting Killing isometries is well-known to be classically integrable. The resulting system typically features a coset σ-model coupled to a dilaton and a scale factor of the dimensional reduction.
Mattia Cesàro, David Osten
doaj   +1 more source

Combined Effects of Microgravity and Chronic Low-Dose Gamma Radiation on Brassica rapa Microgreens

open access: yesPlants
Plants in space face unique challenges, including chronic ionizing radiation and reduced gravity, which affect their growth and functionality. Understanding these impacts is essential to determine the cultivation conditions and protective shielding needs
Sara De Francesco   +7 more
doaj   +1 more source

Workflow for Design of Experiments‐Based Modeling of Species Transport and Growth Kinetics in GaN Hydride Vapor Phase Epitaxy

open access: yesAdvanced Engineering Materials, EarlyView.
A novel workflow for investigating hydride vapor phase epitaxy for GaN bulk crystal growth is proposed. It combines Design of experiments (DoE) with physical simulations of mass transport and crystal growth kinetics, serving as an intermediate step between DoE and experiments.
J. Tomkovič   +7 more
wiley   +1 more source

High‐Resolution Corrosion Fingerprinting of Alloy Libraries via Microdroplet Spectroelectrochemistry

open access: yesAdvanced Engineering Materials, EarlyView.
Ionic‐liquid microdroplet spectroelectrochemistry enables stable, localized electrochemical measurements over extended timescales. By coupling impedance spectroscopy, wetting analysis, finite‐element simulations, and operando Raman spectroscopy, it disentangles geometrical and electrochemical effects, opening new opportunities for rapid corrosion ...
Ekaterina Kurchavova   +3 more
wiley   +1 more source

Reduced Gravity Testing and Research Capabilities at Queensland University Of Technology’s New 2.0 Second Drop Tower [PDF]

open access: yes, 2007
Reduced gravity experimentation is important to many research groups working in various fields investigating both fundamental and applied aspects of diverse physical phenomena.
Steinberg, Ted
core   +1 more source

Investigating the Effect of Inclination Angle and the Influence of Scan Parameters on the Appearance and Thermal and Mechanical Properties of Filigree Tension Rods of LPBF‐Manufactured NiTi Shape‐Memory Alloys

open access: yesAdvanced Engineering Materials, EarlyView.
This article investigates the dependence of the properties on the manufacturing orientation in the form of the inclination angle to the build plate of LPBF‐fabricated NiTi rods with a diameter of 150–220 µm. Metallographic, chemical, thermal, and mechanical characterization show behavior under identical manufacturing conditions that ranges from ...
Sandra Herzig   +2 more
wiley   +1 more source

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