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Related papers: Dynamics of Cities

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Zipf's law is one the most conspicuous empirical facts for cities, however, there is no convincing explanation for the scaling relation between rank and size and its scaling exponent. Based on the idea from general fractals and scaling,…

Physics and Society · Physics 2018-12-20 Yanguang Chen

Inspired by one--dimensional light--particle systems, the dynamics of a non-Hamiltonian system with long--range forces is investigated. While the molecular dynamics does not reach an equilibrium state, it may be approximated in the…

Statistical Mechanics · Physics 2019-01-23 Romain Bachelard , Nicola Piovella , Shamik Gupta

Observations of galaxies over large distances reveal the possibility of a fractal distribution of their positions. The source of fractal behavior is the lack of a length scale in the two body gravitational interaction. However, even with…

Mathematical Physics · Physics 2007-05-23 Bruce N. Miller , Jean-Louis Rouet , Emmanuel Le Guirriec

We use the mesoscopic nonequilibrium thermodynamics theory to derive the general kinetic equation of a system in the presence of potential barriers. The result is applied to the description of the evolution of systems whose dynamics is…

Statistical Mechanics · Physics 2016-08-16 D. Reguera , J. M. Rubí

We use Molecular Dynamics combined with Dissipative Particle Dynamics to construct a model of a binary mixture where the two species differ only in their dynamic properties (friction coefficients). For an asymmetric mixture of slow and fast…

Soft Condensed Matter · Physics 2009-11-11 Jacqueline Yaneva , Burkhard Duenweg , Andrey Milchev

We analyze the effect of nonlinear boundary conditions on an advection-diffusion equation on the half-line. Our model is inspired by models for crystal growth where diffusion models diffusive relaxation of a displacement field, advection is…

Analysis of PDEs · Mathematics 2019-09-06 Antoine Pauthier , Arnd Scheel

The silo discharge process is studied by molecular dynamics simulations. The development of the velocity profile and the probability density function for the displacements in the horizontal and vertical axis are obtained. The PDFs obtained…

Statistical Mechanics · Physics 2009-11-11 R. Arevalo , A. Garcimartin , D. Maza

We study an approach to simulating the stochastic relativistic advection-diffusion equation based on the Metropolis algorithm. We show that the dissipative dynamics of the boosted fluctuating fluid can be simulated by making random…

Nuclear Theory · Physics 2025-02-18 Gokce Basar , Jay Bhambure , Rajeev Singh , Derek Teaney

We study the contribution of advection by thermal velocity fluctuations to the effective diffusion coefficient in a mixture of two identical fluids. The steady-state diffusive flux in a finite system subject to a concentration gradient is…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 A. Donev , A. de la Fuente , J. B. Bell , A. L. Garcia

We use fluctuating hydrodynamics to analyze the dynamical properties in the non-equilibrium steady state of a diffusive system coupled with reservoirs. We derive the two-time correlations of the density and of the current in the…

Statistical Mechanics · Physics 2016-11-23 Tridib Sadhu , Bernard Derrida

High angular resolution diffusion imaging data is the observed characteristic function for the local diffusion of water molecules in tissue. This data is used to infer structural information in brain imaging. Nonparametric scalar measures…

Applications · Statistics 2011-08-17 Sofia C. Olhede , Brandon Whitcher

We examine the existence of nonlinear modes and their temporal dynamics, in arrays of split-ring resonators, using a fractional extension of the Laplacian in the evolution equation. We find a closed-form expression for the dispersion…

Pattern Formation and Solitons · Physics 2020-12-30 Mario I. Molina

The current science of cities can provide a useful foundation for future urban policies, provided that these proposals have been validated by correct observations of the diversity of situations in the world. However, international…

Physics and Society · Physics 2020-05-21 Juste Raimbault , Eric Denis , Denise Pumain

We consider two sequential models of deposition and aggregation for particles. The first model (No Diffusion) simulates surface diffusion through a deterministic capture area, while the second (Sequential Diffusion) allows the atoms to…

Materials Science · Physics 2007-05-23 Daniele Vilone , Claudio Castellano , Paolo Politi

We study a fractional reaction-diffusion system with two types of variables: activator and inhibitor. The interactions between components are modeled by cubical nonlinearity. Linearization of the system around the homogeneous state provides…

Pattern Formation and Solitons · Physics 2007-05-23 V. Gafiychuk , B. Datsko , V. Meleshko

In the present work, we investigate the potential of fractional derivatives to model atmospheric dispersion of pollutants. We propose simple fractional differential equation models for the steady state spatial distribution of concentration…

Atmospheric and Oceanic Physics · Physics 2017-02-22 A. G. O. Goulart , M. J. Lazo , J. M. S. Suarez , D. M. Moreira

We discuss several models of the dynamics of interacting populations. The models are constructed by nonlinear differential equations and have two sets of parameters: growth rates and coefficients of interaction between populations. We…

Adaptation and Self-Organizing Systems · Physics 2013-07-29 Nikolay K. Vitanov , Zlatinka I. Dimitrova

We look at chaotic systems evolving in fractal phase space. The entropy change in time due to the fractal geometry is assimilated to the information growth through the scale refinement. Due to the incompleteness, at any scale, of the…

Statistical Mechanics · Physics 2015-06-24 Q. A. Wang , A. Le Mehaute

We formulate a nonlocal cohesive model for calculating the deformation state inside a cracking body. In this model a more complete set of physical properties including elastic and softening behavior are assigned to each point in the medium.…

Analysis of PDEs · Mathematics 2015-07-14 Robert Lipton

Competing styles in Statistical Mechanics have been introduced to investigate physico-chemical systems displaying complex structures, when one faces difficulties to handle the standard formalism in the well established Boltzmann-Gibbs…