Statistical ensemble approach to stress transmission in granular packings

Abstract

In this emerging-area review article, I discuss the application of entropic principles to understanding stress fluctuations in dry granular matter close to jamming. The paper reviews recent work that clarifies the conditions necessary for the definition of intensive variables such as compactivity and angoricity of granular packings, and tests of the canonical ensembles resulting from these definitions. The stress ensemble, in which the compactivity is infinite and fluctuations are controlled only by the angoricity, has been used to calculate spatial and temporal correlation functions of stress, and these are discussed in detail. The review closes with an outlook for the future.