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Related papers: On Einstein's effective viscosity formula

200 papers

A new microscopic formula for the viscosity of liquids and solids is derived rigorously from a first-principles (microscopically reversible) Hamiltonian for particle-bath atomistic motion. The derivation is done within the framework of…

Soft Condensed Matter · Physics 2024-04-17 Alessio Zaccone

Starting with an expression, due originally to Einstein, for the shear viscosity \textit{$\eta $}(\textit{$\delta \phi $}) of a liquid having a small fraction \textit{$\delta \phi $}by volume of solid particulate matter suspended in it at…

Soft Condensed Matter · Physics 2007-05-23 N. Kumar

Assuming conformally flat metric we obtain inhomogeneous solutions of Einstein equations with the energy-momentum of a viscous fluid. We suggest that the viscous solution can be applied as a model of an expanding inhomogeneous dark energy.

General Relativity and Quantum Cosmology · Physics 2020-03-31 Z. Haba

We investigate the origin of the breakdown of the Stokes-Einstein relation (SER) between diffusivity and viscosity in undercooled melts. A binary Lennard-Jones system, as a model for a metallic melt, is studied by molecular dynamics. A weak…

Disordered Systems and Neural Networks · Physics 2016-06-22 H. R. Schober , H. L. Peng

We present the first generalization of Navier-Stokes theory to relativity that satisfies all of the following properties: (a) the system coupled to Einstein's equations is causal and strongly hyperbolic; (b) equilibrium states are stable;…

General Relativity and Quantum Cosmology · Physics 2022-03-02 Fabio S. Bemfica , Marcelo M. Disconzi , Jorge Noronha

This paper is dedicated to the effective viscosity of suspensions without inertia, at low solid volume fraction $\phi$. The goal is to derive rigorously a $o(\phi^2)$ formula for the effective viscosity. In previous works, such formula was…

Analysis of PDEs · Mathematics 2021-03-16 David Gerard-Varet

Effective theory arguments are used to derive the most general energy-momentum tensor of a relativistic viscous fluid with an arbitrary equation of state (in the absence of other conserved currents) that is first-order in the derivatives of…

General Relativity and Quantum Cosmology · Physics 2022-02-22 Fábio S. Bemfica , Marcelo M. Disconzi , Jorge Noronha

We prove that Einstein's equations coupled to equations of Israel-Stewart-type, describing the dynamics of a relativistic fluid with bulk viscosity and nonzero baryon charge (without shear viscosity or baryon diffusion) dynamically coupled…

General Relativity and Quantum Cosmology · Physics 2019-07-03 Fabio S. Bemfica , Marcelo M. Disconzi , Jorge Noronha

Suspension of particles in a fluid solvent are ubiquitous in nature, for example, water mixed with sugar or bacteria self-propelling through mucus. Particles create local flow perturbations that can modify drastically the effective…

Soft Condensed Matter · Physics 2024-10-16 S. Dang , C. Blanch-Mercader , L. Berlyand

We propose an improved viscosity model accounting for experiments of emulsions of two immiscible liquids at arbitrary volume fractions and low shear rates. The model is based on a recursive-differential method formulated in terms of the…

Soft Condensed Matter · Physics 2009-04-01 Carlos I. Mendoza , I. Santamaria-Holek

We study effective shear viscosity $\mu^\star$ and effective extensional viscosity $\lambda^\star$ of concentrated non-colloidal suspensions of rigid spherical particles. The focus is on the spatially disordered arrays. We use recently…

Fluid Dynamics · Physics 2007-05-23 Leonid Berlyand , Alexander Panchenko

The method employed by Einstein to derive his famous relation between the diffusion coefficient and the friction coefficient of a Brownian particle is used to derive a generalized Einstein relation for the mutual diffusion coefficient of a…

Fluid Dynamics · Physics 2017-09-13 B. U. Felderhof

From the smallest scales of quantum systems to the largest scales of intergalactic medium, turbulence is ubiquitous in nature. Often dubbed as the last unsolved problem of classical physics, it remains a time tested paradigm of dynamics far…

Fluid Dynamics · Physics 2021-09-23 Sanjay CP , Ashwin Joy

In this manuscript, we put forth a general scheme for defining initial value problems from Einstein's equations of General Relativity constrained by homogeneous and isotropic expansion. The cosmological models arising as solutions are…

General Relativity and Quantum Cosmology · Physics 2024-08-06 Leandro G. Gomes , Marcelo A. C. Nogueira , Lucas Ruiz dos Santos

The aim of this article is twofold. First, we develop a unified framework for viscosity solutions to both first-order Hamilton-Jacobi equations and semilinear Hamilton-Jacobi equations driven by the idiosyncratic operator, defined on the…

Analysis of PDEs · Mathematics 2026-01-22 Giacomo Ceccherini Silberstein , Daniela Tonon

The Einstein postulates assert an invariance of the propagation speed of light in vacuum for any observer, and which amounts to a presumed absence of any preferred frame. The postulates appear to be directly linked to relativistic effects…

General Physics · Physics 2007-08-07 Reginald T. Cahill

Active particles with a temperature distribution, "hot particles", have a distinct effect on the fluid that surrounds them. The temperature gradients they create deem the fluid's viscosity spatially dependent, therefore violating the…

Soft Condensed Matter · Physics 2024-08-27 Osher Arbib , Naomi Oppenheimer

Using a simple and well-motivated modification of the stress-energy tensor for a viscous fluid proposed by Lichnerowicz, we prove that Einstein's equations coupled to a relativistic version of the Navier-Stokes equations are well-posed in a…

Mathematical Physics · Physics 2014-07-25 Marcelo M. Disconzi

We give a derivation of the Einstein equation for gravity which employs a definition of the local energy density of the gravitational field as a symmetric second rank tensor whose value for each observer gives the trace of the spatial part…

Mathematical Physics · Physics 2008-03-13 Maurice J. Dupre

The Einstein relation describes the response of a diffusing particle to a small constant external force. It states that, as the force tends to zero, the ratio of the limiting velocity to the force magnitude converges to the diffusivity…

Probability · Mathematics 2026-05-26 Ahmed Bou-Rabee , Ruizhe Xu