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Related papers: Nonextensive statistics in viscous fingering

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The emergence of heavy-tailed statistics in complex systems is conventionally attributed to non-local stochastic jumps or non-Markovian memory. Here, we present a one-dimensional random walk where power-law behaviors arise instead from a…

Statistical Mechanics · Physics 2026-05-25 Henrique S. Lima , Evaldo M. F. Curado

We perform direct numerical simulations of the flow through a model of a deformable porous medium. Our model is a two-dimensional hexagonal lattice, with defects, of soft elastic cylindrical pillars, with elastic shear modulus $G$, immersed…

Fluid Dynamics · Physics 2021-09-09 Marco E. Rosti , Satyajit Pramanik , Luca Brandt , Dhrubaditya Mitra

Our experiments on viscous (Saffman-Taylor) fingering in Hele-Shaw channels reveal finger width fluctuations that were not observed in previous experiments, which had lower aspect ratios and higher capillary numbers Ca. These fluctuations…

Soft Condensed Matter · Physics 2009-11-07 Mitchell G. Moore , Anne Juel , John M. Burgess , W. D. McCormick , Harry L. Swinney

We study relaxation toward statistical equilibrium states of inviscid generalised two-dimensional flows, where the generalised vorticity $q$ is related to the streamfunction $\psi$ via $q=(-\nabla^2)^{\frac{\alpha}{2}}\psi$, with the…

Fluid Dynamics · Physics 2026-01-09 Vibhuti Bhushan Jha , Kannabiran Seshasayanan , Vassilios Dallas

A Hele-Shaw cell is a device used to study fluid flow between two parallel plates separated by a small gap. The governing equation of flow within a Hele-Shaw cell is Darcy's law, which also describes flow through a porous medium. In this…

Fluid Dynamics · Physics 2023-05-25 Dylan Reynolds , Gustavo M. Monteiro , Sriram Ganeshan

Non-particulate continuum descriptions allow for computationally efficient modeling of suspension flows at scales that are inaccessible to more detailed particulate approaches. It is well known that the presence of particles influences the…

Soft Condensed Matter · Physics 2013-11-13 Florian Janoschek , Jens Harting , Federico Toschi

This paper is concerned with the large-time behavior of solutions to the Cauchy problem on the two-fluid Euler-Maxwell system with collisions when initial data are around a constant equilibrium state. The main goal is the rigorous…

Analysis of PDEs · Mathematics 2014-12-02 Renjun Duan , Qingqing Liu , Changjiang Zhu

Traditional mathematical models of Hele--Shaw flow consider the injection (or withdrawal) of an air bubble into (or from) an infinite body of viscous fluid. The most commonly studied feature of such a model is how the Saffman-Taylor…

Fluid Dynamics · Physics 2023-01-19 Liam C. Morrow , Nicolas De Cock , Scott W. McCue

The discretized equilibrium distributions of the lattice Boltzmann method are presented by using the coefficients of the Lagrange interpolating polynomials that pass through the points related to discrete velocities and using moments of the…

Computational Physics · Physics 2020-11-10 Jae Wan Shim

The distribution of money is analysed in connection with the Boltzmann distribution of energy in the degenerate states of molecules. Plots of the population density of income distribution for various countries are well reproduced by a Gamma…

Statistical Mechanics · Physics 2009-11-10 Juan C. Ferrero

We address the experimentally observed non-Gaussian fluctuations for the energy injected into a closed turbulent flow at fixed Reynolds number. We propose that the power fluctuations mirror the internal kinetic energy fluctuations. Using a…

Statistical Mechanics · Physics 2007-05-23 B. Portelli , P. C. W. Holdsworth , J. -F. Pinton

Violent relaxation has been proposed half a century ago to bear responsibility for non-collisional dynamics and formation of gravitationally bound systems of extended celestial objects (agglomeration of stars, galaxies, clusters of…

Astrophysics of Galaxies · Physics 2013-10-03 R. A. Treumann , W. Baumjohann

Usually, the transverse momentum distribution is described by a sum of an exponential decay term plus a decreasing power like contribution representing the soft non-perturbative and hard perturbative QCD collisions, respectively. In this…

High Energy Physics - Phenomenology · Physics 2022-12-20 C. Pajares , J. E. Ramírez

We present a further theoretical extension to the kinetic theory based formulation of the lattice Boltzmann method of Shan et al (2006). In addition to the higher order projection of the equilibrium distribution function and a sufficiently…

Computational Physics · Physics 2009-11-11 Raoyang Zhang , Xiaowen Shan , Hudong Chen

We present an analysis of diffusion in terms of the spontaneous density fluctuations in a non-thermal two-species fluid modeled by a lattice gas automaton. The power spectrum of the density correlation function is computed with statistical…

Statistical Mechanics · Physics 2009-10-30 David Hanon , Jean Pierre Boon

This review is a kinetic theory study investigating the effects of inelasticity on the structure of the non-equilibrium states, in particular on the behavior of the velocity distribution in the high energy tails. Starting point is the…

Statistical Mechanics · Physics 2007-05-23 R. Brito , M. H. Ernst

Martensites subjected to quasistatic deformation are known to exhibit power law distributed acoustic emission in a broad range of scales, however, the origin of the observed scaling behavior and the mechanism of self-organization towards…

Materials Science · Physics 2025-07-08 Oğuz Umut Salman , Alphonse Finel , Lev Truskinovsky

In this paper we present a new derivation of the $H$-theorem and the corresponding collisional equilibrium velocity distributions, within the framework of Tsallis' nonextensive thermostatistics. Unlike previous works, in our derivation we…

Statistical Mechanics · Physics 2009-11-10 Fernando M. Ramos , Reinaldo R. Rosa , Luis A. W. Bambace

Level and wavefunction statistics have been studied for two dimensional clusters of the square lattice in the presence of random magnetic fluxes. Fluxes traversing lattice plaquettes are distributed uniformly between - (1/2) Phi_0 and (1/2)…

Condensed Matter · Physics 2009-10-28 J. A. Verges

Sampling the Boltzmann distribution using forces that violate detailed balance can be faster than with the equilibrium evolution, but the acceleration depends on the nature of the nonequilibrium drive and the physical situation. Here, we…

Soft Condensed Matter · Physics 2023-12-20 Federico Ghimenti , Ludovic Berthier , Grzegorz Szamel , Frédéric van Wijland