Stationary mass distribution and nonlocality in models of coalescence and shattering

TL;DR

This paper analyzes the steady state mass distribution in aggregation-shattering models, revealing how local and non-local collision kernels influence asymptotic behaviors, with implications for universality classes based on kernel properties.

Contribution

It classifies the asymptotic behaviors of mass distributions based on local and non-local collision kernels, introducing new regimes and calculating logarithmic corrections at regime boundaries.

Findings

Local kernels lead to constant mass flux solutions.

Non-local kernels exhibit corrections to flux exponents.

Logarithmic corrections appear at local/non-local boundaries.

Abstract

We study the asymptotic properties of the steady state mass distribution for a class of collision kernels in an aggregation-shattering model in the limit of small shattering probabilities. It is shown that the exponents characterizing the large and small mass asymptotic behavior of the mass distribution depend on whether the collision kernel is local (the aggregation mass flux is essentially generated by collisions between particles of similar masses), or non-local (collision between particles of widely different masses give the main contribution to the mass flux). We show that the non-local regime is further divided into two sub-regimes corresponding to weak and strong non-locality. We also observe that at the boundaries between the local and non-local regimes, the mass distribution acquires logarithmic corrections to scaling and calculate these corrections. Exact solutions for special kernels and numerical simulations are used to validate some non-rigorous steps used in the analysis. Our results show that for local kernels, the scaling solutions carry a constant flux of mass due to aggregation, whereas for the non-local case there is a correction to the constant flux exponent. Our results suggest that for general scale-invariant kernels, the universality classes of mass distributions are labeled by two parameters: the homogeneity degree of the kernel and one further number measuring the degree of the non-locality of the kernel.