Search results for " Entropy"

showing 10 items of 236 documents

Maximum Entropy Limit of Small-scale Magnetic Field Fluctuations in the Quiet Sun

2017

The observed magnetic field on the solar surface is characterized by a very complex spatial and temporal behavior. Although feature-tracking algorithms have allowed us to deepen our understanding of this behavior, subjectivity plays an important role in the identification and tracking of such features. In this paper, we continue studies Gorobets, A. Y., Borrero, J. M., & Berdyugina, S. 2016, ApJL, 825, L18 of the temporal stochasticity of the magnetic field on the solar surface without relying either on the concept of magnetic features or on subjective assumptions about their identification and interaction. We propose a data analysis method to quantify fluctuations of the line-of-sight …

PhysicsConvectionPhotosphere010504 meteorology & atmospheric sciencesScale (ratio)Principle of maximum entropyFOS: Physical sciencesAstronomy and Astrophysics01 natural sciencesMagnetic fieldAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary ScienceQuantum electrodynamicsQUIET0103 physical sciencesAstrophysics::Solar and Stellar AstrophysicsLimit (mathematics)010303 astronomy & astrophysicsSolar and Stellar Astrophysics (astro-ph.SR)0105 earth and related environmental sciences
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Compact Topological Quantum Groups

1995

Using vector spaces topologies we unify the different models of quantum groups. Duality and reflexivity are built in. The Drinfeld deformation can be extended to the distributions on a simple compact Lie group and dually to the infinitely differentiable functions. The topological quantum double is similarly defined and a uniqueness result is obtained.

PhysicsDuality (mathematics)Topological orderTopological ringLie groupCompact quantum groupQuantum topologyTopologySymmetry protected topological orderTopological entropy in physics
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Structure Determination by Electron Crystallography Using a Simulation Approach Combined with Maximum Entropy with the Aim of Improving Material Prop…

1997

Solving a crystal structure is only one of the many problems involved in the process of improving material properties. Because it is difficult to obtain large single crystals from most polymeric and many monomeric organic materials, it is essential to develop electron crystallography to make reliable crystal structure analysis possible.

PhysicsElectron diffraction patternChemical physicsElectron crystallographyScientific methodPrinciple of maximum entropyStructure (category theory)Physical chemistryCrystal structureMaterial properties
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Entropy function from toric geometry

2021

It has recently been claimed that a Cardy-like limit of the superconformal index of 4d $\mathcal{N}=4$ SYM accounts for the entropy function, whose Legendre transform corresponds to the entropy of the holographic dual AdS$_5$ rotating black hole. Here we study this Cardy-like limit for $\mathcal{N}=1$ toric quiver gauge theories, observing that the corresponding entropy function can be interpreted in terms of the toric data. Furthermore, for some families of models, we compute the Legendre transform of the entropy function, comparing with similar results recently discussed in the literature.

PhysicsHigh Energy Physics - TheoryNuclear and High Energy PhysicsSettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciQuiverFOS: Physical sciencesToric varietyBlack hole entropy Black hole microstates superconformal index AdS/CFTQC770-798Binary entropy functionLegendre transformationEntropy (classical thermodynamics)symbols.namesakeHigh Energy Physics - Theory (hep-th)Rotating black holeNuclear and particle physics. Atomic energy. RadioactivitysymbolsLimit (mathematics)Gauge theoryMathematical physicsNuclear Physics B
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Configurational entropy of microemulsions : The fundamental length scale

1993

Phenomenological models have been quite successful in characterizing both the various complex phases and the corresponding phase diagrams of microemulsions. In some approaches, e.g., the random mixing model (RMM), the lattice parameter is of the order of the dimension of an oil or water domain and has been used as a length scale for computing a configurational entropy, the so‐called entropy of mixing, of the microemulsion. In the central and material section of this paper (Sec. III), we show that the fundamental length scale for the calculation of the entropy of mixing is of the order of the cube root of the volume per molecule—orders of magnitude smaller than the dimension of such a domain…

PhysicsLength scalePhase StudiesEntropyConfiguration entropyGeneral Physics and AstronomyThermodynamicsEntropy of mixingMicroemulsions ; Entropy ; Phase Diagrams ; Lattice Parameters ; Dispersions ; Phase StudiesUNESCO::FÍSICA::Química físicaPhase spacePhenomenological modelMicroemulsionsLattice ParametersStatistical physicsConfiguration spacePhase DiagramsPhysical and Theoretical ChemistryEntropy (energy dispersal)Dispersions:FÍSICA::Química física [UNESCO]Cube root
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The Maximum Entropy Formalism.

1980

PhysicsMaximum entropy formalismMathematical physicsJournal of the Royal Statistical Society. Series A (General)
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Understanding the glass transition and the amorphous state of matter: can computer simulation solve the challenge?

1999

The glass transition of supercooled fluids is one of the big puzzles of condensed matter physics, because there occurs a dramatic slowing down (the viscosity η can increase from about η = 1 Poise at the melting transition to η 10 13 Poise at the glass transition temperature T g ), but one hardly sees any accompanying change in the static structure. Theoretical concepts are very controversial - e.g., the Gibbs-di Marzio theory attributes glassy freezing to an underlying entropy catastrophe (the entropy of the supercooled fluid would fall below the crystal entropy at the Kauzmann temperature T 0 T g . Computer simulations offer the advantage that atomistically detailed information on structur…

PhysicsMolecular dynamicsHardware and ArchitectureConfiguration entropyRelaxation (NMR)Mode couplingState of matterGeneral Physics and AstronomyStatistical physicsGlass transitionSupercoolingAmorphous solidComputer Physics Communications
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Combinatorics of theSU(2)black hole entropy in loop quantum gravity

2009

We use the combinatorial and number-theoretical methods developed in previous works by the authors to study black hole entropy in the new proposal put forth by Engle, Noui, and Perez. Specifically, we give the generating functions relevant for the computation of the entropy and use them to derive its asymptotic behavior, including the value of the Immirzi parameter and the coefficient of the logarithmic correction.

PhysicsNuclear and High Energy PhysicsConfiguration entropyImmirzi parameterTheoryofComputation_GENERALLoop quantum gravityBinary entropy functionGeneral Relativity and Quantum CosmologyTheoretical physicsClassical mechanicsQuantum gravityBlack hole thermodynamicsEntropy (arrow of time)Joint quantum entropyPhysical Review D
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The EM imaging reconstruction method in γ-ray astronomy

1998

Abstract The simpler imaging reconstruction methods used for γ-ray coded mask telescopes are based on correlation methods, very fast and simple-to-use but with limitations in the reconstructed image. To improve these results, other reconstruction methods have been developed, such as the maximum entropy methods or the Iterative Removal Of Sources (IROS). However, such kind of methods are slower and can be impracticable for very complex telescopes. In this paper we present an alternative image reconstruction method, based on an iterative maximum likelihood algorithm called the EM algorithm, easy to implement and that can be successfully used for not very complex coded mask systems, as is the …

PhysicsNuclear and High Energy PhysicsPrinciple of maximum entropyComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONAstrophysics::Instrumentation and Methods for AstrophysicsAstronomyComputerApplications_COMPUTERSINOTHERSYSTEMSIterative reconstructionReconstruction methodlaw.inventionTelescopeMaximum likelihood algorithmlawExpectation–maximization algorithmCorrelation methodReconstructed imageInstrumentationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Entropy production and information fluctuations along quantum trajectories

2013

Employing the stochastic wave function method, we study quantum features of stochastic entropy production in nonequilibrium processes of open systems. It is demonstarted that continuous measurements on the environment introduce an additional, non-thermal contribution to the entropy flux, which is shown to be a direct consequence of quantum fluctuations. These features lead to a quantum definition of single trajectory entropy contributions, which accounts for the difference between classical and quantum trajectories and results in a quantum correction to the standard form of the integral fluctuation theorem.

PhysicsQuantum PhysicsQuantum discordQuantum ThermodynamicSettore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciStatistical Mechanics (cond-mat.stat-mech)EntropyFOS: Physical sciencesAtomic and Molecular Physics and OpticsQuantum relative entropySettore FIS/03 - Fisica Della MateriaGeneralized relative entropyQuantum probabilityClassical mechanicsQuantum processQuantum InformationQuantum dissipationAmplitude damping channelQuantum Physics (quant-ph)Condensed Matter - Statistical MechanicsJoint quantum entropy
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