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Related papers: Critical velocity averaging lemmas

200 papers

We compute the joint distribution of relative velocities and separations of identical inertial particles suspended in randomly mixing and turbulent flows. Our results are obtained by matching asymptotic forms of the distribution. The method…

Fluid Dynamics · Physics 2014-02-24 K. Gustavsson , B. Mehlig

(context) Different cosmological data are consistent with an accelerated expansion produced by an exotic matter-energy component, dubbed "dark-energy''. A cosmological constant is a possibility since it satisfies most of the observational…

Astrophysics · Physics 2010-01-15 Sébastien Peirani , José Antonio De Freitas Pacheco

This paper investigates an inverse source problem for general semilinear stochastic hyperbolic equations. Motivated by the challenges arising from both randomness and nonlinearity, we develop a globally convergent iterative regularization…

Analysis of PDEs · Mathematics 2025-04-25 Qi Lü , Yu Wang

What does it mean to ``add'' velocities relativistically -- clarification of the conceptual problems, new derivations of the related formulas, and identification of the source of the non-associativity of the standard vector version of the…

General Relativity and Quantum Cosmology · Physics 2019-10-16 Jerzy Kocik

The statistics of velocity differences between very heavy inertial particles suspended in an incompressible turbulent flow is found to be extremely intermittent. When particles are separated by distances within the viscous subrange, the…

Fluid Dynamics · Physics 2009-05-11 J. Bec , L. Biferale , M. Cencini , A. S. Lanotte , F. Toschi

This paper investigates a new class of equations called measure functional differential equations with state-dependent delays. We establish the existence and uniqueness of solutions and present a discussion concerning the appropriate phase…

Optimization and Control · Mathematics 2024-12-31 Jaqueline G. Mesquita , Tiago Roux Oliveira , Henrique C. dos Reis

Additive noise in Partial Differential equations, in particular those of fluid mechanics, has relatively natural motivations. The aim of this work is showing that suitable multiscale arguments lead rigorously, from a model of fluid with…

Probability · Mathematics 2022-05-12 Franco Flandoli , Umberto Pappalettera

We compute the distribution of relative velocities for a one-dimensional model of heavy particles suspended in a turbulent flow, quantifying the caustic contribution to the moments of relative velocities. The same principles determine the…

Fluid Dynamics · Physics 2012-06-13 K. Gustavsson , B. Mehlig

We obtain space-time H\"older regularity estimates for solutions of first- and second-order Hamilton-Jacobi equations perturbed with an additive stochastic forcing term. The bounds depend only on the growth of the Hamiltonian in the…

Analysis of PDEs · Mathematics 2021-03-02 Pierre Cardaliaguet , Benjamin Seeger

In this paper, we establish $L_p$ estimates and solvability for time fractional divergence form parabolic equations in the whole space when leading coefficients are merely measurable in one spatial variable and locally have small mean…

Analysis of PDEs · Mathematics 2019-08-20 Hongjie Dong , Doyoon Kim

This paper is devoted to studying the averaging principle for stochastic differential equations with slow and fast time-scales, where the drift coefficients satisfy local Lipschitz conditions with respect to the slow and fast variables, and…

Probability · Mathematics 2020-08-19 Wei Liu , Michael Röckner , Xiaobin Sun , Yingchao Xie

We obtain optimal moment bounds for Birkhoff sums, and optimal concentration inequalities, for a large class of slowly mixing dynamical systems, including those that admit anomalous diffusion in the form of a stable law or a central limit…

Dynamical Systems · Mathematics 2017-09-01 Sébastien Gouëzel , Ian Melbourne

In this paper Gaussian models of retarded and accelerated anomalous diffusion are considered. Stochastic differential equations of fractional order driven by single or multiple fractional Gaussian noise terms are introduced to describe…

Statistical Mechanics · Physics 2014-05-08 Chai Hok Eab , S. C. Lim

Near the critical point, isothermal interfacial zones are investigated starting from a non-local density of energy. From the equations of motion of thermocapillary fluids, we point out a new kind of adiabatic waves propagating along the…

Fluid Dynamics · Physics 2008-01-16 Henri Gouin

We consider a degenerate abstract wave equation with a time-dependent propagation speed. We investigate the influence of a strong dissipation, namely a friction term that depends on a power of the elastic operator. We discover a threshold…

Analysis of PDEs · Mathematics 2017-10-11 Marina Ghisi , Massimo Gobbino

We study the propagation of regularity of solutions to a three dimensional system of linear parabolic PDE known as the kinematic dynamo equations. The divergence free drift velocity is assumed to be at the critical regularity level with…

Analysis of PDEs · Mathematics 2015-06-19 Susan Friedlander , Anthony Suen

We develop a quantitative theory of stochastic homogenization for linear, uniformly parabolic equations with coefficients depending on space and time. Inspired by recent works in the elliptic setting, our analysis is focused on certain…

Analysis of PDEs · Mathematics 2018-06-13 Scott Armstrong , Alexandre Bordas , Jean-Christophe Mourrat

Based on thermodynamic considerations we derive a set of equations relating the seepage velocities of the fluid components in immiscible and incompressible two-phase flow in porous media. They necessitate the introduction of a new velocity…

We consider partially hyperbolic attractors for non-singular endomorphisms admitting an invariant stable bundle and a positively invariant cone field with non-uniform cone expansion at a positive Lebesgue measure set of points. We prove…

Dynamical Systems · Mathematics 2018-10-08 Anderson Cruz , Giovane Ferreira , Paulo Varandas

Our goal is to establish existence with suitable initial data of solutions to general parabolic equation in one dimension, $u_t = L(u_x)_x$, where $L$ is merely a monotone function. We also expose the basic properties of solutions,…

Analysis of PDEs · Mathematics 2012-07-23 Piotr Bogusław Mucha , Piotr Rybka