Topological character of hydrodynamic screening in suspensions of hard spheres: an example of universal phenomenon

TL;DR

This paper demonstrates the existence of hydrodynamic screening in suspensions of hard spheres, showing it as a universal phenomenon analogous to superconductivity, with implications for various physical systems.

Contribution

It introduces a topological and combinatorial approach to prove hydrodynamic screening in suspensions, extending concepts from superconductivity to colloidal suspensions.

Findings

Hydrodynamic screening exists in suspensions of hard spheres.

The extent of screening depends on the volume fraction of spheres.

Divergence of relative viscosity is explained by a topological transition.

Abstract

Although in the case of polymer solutions the existence of hydrodynamic screening is considered as established, use of the same methods for suspensions of hard spheres so far have failed to produce similar results. In this work we reconsider this problem. Using superposition of topological, combinatorial and London-style qualitative arguments, we prove the existence of screening in suspensions. We show that the nature of hydrodynamic screening in suspensions is analogous to that known for the Meissner effect in superconductors. The extent of screening depends on volume fraction of hard spheres. The zero volume fraction limit corresponds to the normal state. The case of finite volume fractions-to the mixed state typical for superconductors of the second kind. Such a state is becoming fully "superconducting" at some critical volume fraction for which the (zero frequency) relative viscosity diverges. Our analytical results describing this divergence are in accord with known scaling results obtained by Brady and Bicerano et al which are well supported by experimental data. We provide theoretical explanation of the divergence of relative viscosity in terms of a topological-type transition which mathematically can be made isomorphic to the more familiar Bose-Einstein condensation transition. Because of this, the methods developed in this work are not limited to suspensions only. In concluding section we mention other applications of the developed formalism ranging from turbulence and magnetohydrodynamics to high temperature superconductors, QCD, string models, etc.