Mesoscopic Fluctuations in Statistical Systems

TL;DR

This paper reviews mesoscopic fluctuations, which are intermediate-sized variations in various systems, highlighting their theoretical description, experimental evidence, and applications across condensed matter, atomic, biological, and social systems.

Contribution

It provides a comprehensive survey of experimental evidence and discusses a general theoretical framework for understanding mesoscopic fluctuations across diverse systems.

Findings

Mesoscopic fluctuations occur in many physical and biological systems.

A unified theoretical approach can describe these fluctuations.

Experimental evidence supports the universality of mesoscopic phenomena.

Abstract

The fluctuations are termed mesoscopic, when their typical size is essentially larger then the average distance between the nearest neighbors, while being much smaller than the overall system size. Since the features of mesoscopic fluctuations are essentially different from those of the surrounding matter, they can be interpreted as fluctuations of one phase occurring inside another host phase. In condensed matter, these fluctuations are of nanosize. They can occur in many-body systems of different nature, for instance, they are typical for condensed matter, can appear in systems of trapped atoms, and also arise in biological and social systems. A survey of the experimental evidence for the occurrence of mesoscopic fluctuations in different materials and systems is given. The main attention is paid to a general theoretical approach for describing them. Applications of the approach are also discussed.