Search results for "Kinetic Theory"

showing 10 items of 26 documents

On the modeling of nonlinear interactions in large complex systems

2010

Abstract This work deals with the modeling of large systems of interacting entities in the framework of the mathematical kinetic theory for active particles. The contents are specifically focused on the modeling of nonlinear interactions which is one of the most important issues in the mathematical approach to modeling and simulating complex systems, and which includes a learning–hiding dynamics. Applications are focused on the modeling of complex biological systems and on immune competition.

Non lineariteLiving systems Nonlinearity Functional subsystems Kinetic theory Active particlesApplied MathematicsActive particlesComplex system010103 numerical & computational mathematics01 natural sciencesActive particlesLiving systems010101 applied mathematicsNonlinear systemLiving systemsFunctional subsystems0101 mathematicsKinetic theoryBiological systemComplex systems biologyNonlinearitySettore MAT/07 - Fisica MatematicaAlgorithmMathematicsApplied Mathematics Letters
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Theory overview of Heavy Ion collisions

2016

This presentation discusses some recently active topics in the theoretical interpretation of high energy heavy ion collisions at the LHC and at RHIC. We argue that the standard paradigm for understanding the spacetime evolution of the bulk of the matter produced in the collision is provided by viscous relativistic hydrodynamics, which can be used to systematically extract properties of the QCD medium from experimental results. The initial conditions of this hydrodynamical evolution are increasingly well understood in terms of gluon saturation, and can be quantified using Classical Yang-Mills fields and QCD effective kinetic theory. Hard and electromagnetic probes of the plasma provide addit…

Particle physicsNuclear Theorynucleus nucleusNuclear TheoryFOS: Physical sciencesNuclear Theory (nucl-th)Nuclear physicsHigh Energy Physics - Phenomenology (hep-ph)quantum chromodynamicsboundary conditionsYang-Millsheavy ionsNuclear ExperimentBrookhaven RHIC CollplasmaQuantum chromodynamicsPhysicsenergiaLarge Hadron ColliderSpacetimesaturationscatteringviskositeettiPlasmaCollisionGluonHigh Energy Physics - Phenomenologyelectromagneticsspace-timekineticsQuark–gluon plasmaKinetic theory of gasesp nucleushydrodynamiikka
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Fluid dynamical response to initial state fluctuations

2014

Abstract We investigate a fluid dynamical response to the fluctuations and geometry of the initial state density profiles in ultrarelativistic heavy ion collisions.

PhysicsNuclear reactionNuclear and High Energy Physicsta114Mathematical model010308 nuclear & particles physicsFluid mechanicsState (functional analysis)Mechanics01 natural sciencesClassical mechanicsFlow (mathematics)State density0103 physical sciencesKinetic theory of gasesHeavy ionNuclear Experiment010306 general physicsNuclear Physics A
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Self-consistent calculation of the flux-flow conductivity in diffusive superconductors

2017

In the framework of Keldysh-Usadel kinetic theory, we study the temperature dependence of flux-flow conductivity (FFC) in diffusive superconductors. By using self-consistent vortex solutions we find the exact values of dimensionless parameters that determine the diffusion-controlled FFC both in the limit of the low temperatures and close to the critical one. Taking into account the electron-phonon scattering we study the transition between flux-flow regimes controlled either by the diffusion or the inelastic relaxation of non-equilibrium quasiparticles. We demonstrate that the inelastic electron-phonon relaxation leads to the strong suppression of FFC as compared to the previous estimates m…

PhysicsSuperconductivityCondensed matter physicsta114ScatteringCondensed Matter - SuperconductivitysuperconductivityNon-equilibrium thermodynamicsFOS: Physical sciencesconductivit01 natural sciences010305 fluids & plasmasVortexSuperconductivity (cond-mat.supr-con)Condensed Matter::SuperconductivityKeldysh-Usadel kinetic theory0103 physical sciencesQuasiparticleRelaxation (physics)Diffusion (business)010306 general physicsDimensionless quantityPhysical Review B
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A Nonlinear Nonviscous Hydrodynamical Model for Change Transport Derived from Kinetic Theory

2002

In the paper, methods of Extended Thermodynamics are used to derive nonlinear closure relations for hydrodynamical models for charge transport in metals or in semiconductors, neglecting viscous phenomena. For the sake of simplicity only the case of single parabolic band approximation is studied. In this work the velocity v i is not considered as a small parameter; therefore, the models obtained can be useful when one wishes to study phenomena in a neighborhood of a stationary non-equilibrium process.

PhysicsWork (thermodynamics)Nonlinear systemConstitutive theoryClassical mechanicsHeat fluxConstitutive equationKinetic theory of gasesClosure (topology)Charge (physics)Statistical physics
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Thermalization in the initial stage of heavy ion collisions

2017

The high density non-abelian matter produced in heavy ion collisions is extremely anisotropic. Prethermal dynamics for the anisotropic and weakly coupled matter is discussed. Thermalization is realized with the effective kinetic theory in the leading order accuracy of the weakly coupled expansion. With the initial condition from color glass condensate, hydrodynamization time for the LHC energies is realized to be about 1 fm/c, while the thermalization happens much later than the hydrodynamization. peerReviewed

PhysicsthermalizationLarge Hadron Colliderta114010308 nuclear & particles physicsPhysicsQC1-999heavy ion collisionsHigh density01 natural sciences7. Clean energyColor-glass condensateNuclear physicsThermalisationChemical physics0103 physical sciencesKinetic theory of gasescolor glass condensatehydrodynamizationInitial value problemHeavy ion010306 general physicsAnisotropyQuark Confinement and the Hadron Spectrum
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Solving the heat-flow problem with transient relativistic fluid dynamics

2014

Israel-Stewart theory is a causal, stable formulation of relativistic dissipative fluid dynamics. This theory has been shown to give a decent description of the dynamical behavior of a relativistic fluid in cases where shear stress becomes important. In principle, it should also be applicable to situations where heat flow becomes important. However, it has been shown that there are cases where Israel-Stewart theory cannot reproduce phenomena associated with heat flow. In this paper, we derive a relativistic dissipative fluid-dynamical theory from kinetic theory which provides a good description of all dissipative phenomena, including heat flow. We explicitly demonstrate this by comparing th…

Physics::Fluid DynamicsPhysicsNuclear and High Energy Physicsta114Quark–gluon plasmaDynamics (mechanics)Fluid dynamicsKinetic theory of gasesDissipative systemShear stressMechanicsTransient (oscillation)Boltzmann equationPhysical Review D
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Kinetic model for steady heat flow

1986

We construct a consistent solution of the Bhatnagar-Gross-Krook (BGK) model kinetic equation describing a system in a steady state with constant pressure and nonuniform temperature. The thermal profile is not linear and depends on the interaction potential. All the moments of the distribution function are given as polynomials in the local thermal gradient. In particular, the heat flux always obeys the (linear) Fourier law.

Physics::Fluid DynamicsPhysicsTemperature gradientSteady stateDistribution functionHeat fluxKinetic modelThermalTurbulence kinetic energyKinetic theory of gasesThermodynamicsMechanicsNonlinear Sciences::Cellular Automata and Lattice GasesPhysical Review A
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A spatially homogeneous mathematical model of immune cancer competition

2015

This paper deals with the modeling of interactions between the immune system and cancer cells, in the framework of the mathematical kinetic theory for active particles. The model assumes spatial homogeneity and continue values of the activity of cancer and immune cells.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciMulticellular systemkinetic theory of active particles.
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From the kinetic theory of active particles to the modeling of social behaviors and politics

2007

This paper deals with the modeling of complex social systems by methods of the mathematical kinetic theory for active particles. Specifically, a recent model by the last two authors is analyzed from the social sciences point of view. The model shows, despite its simplicity, some interesting features. In particular, this paper investigates the ability of the model to describe how a social politics and the disposable overall wealth may have a relevant influence towards the trend of the wealth distribution. The paper also outlines various research perspectives.

Statistics and ProbabilityManagement scienceActive particlesmedia_common.quotation_subjectGeneral Social SciencesComplexitySocial systemsActive particlesPoliticsSocial systemKinetic theory of gasesWealth distributionSimplicitySociologyKinetic theoryNonlinearitySocial psychologySocial politicsSocial behaviormedia_commonQuality & Quantity
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