Turbulence models of gravitational clustering

TL;DR

This paper explores turbulence models for gravitational clustering in cosmic large-scale structures, drawing analogies with fluid turbulence, and proposes a perturbative approach to predict matter density correlations.

Contribution

It introduces a turbulence-inspired model for cosmic structure formation, adapting Kolmogorov's turbulence concepts to the compressible, vorticity-dominated cosmic context.

Findings

Predicts the power-law exponent of the matter density two-point correlation function

Provides a testable framework linking turbulence theory to cosmological observations

Suggests the adhesion model as a simplified yet effective approach

Abstract

Large-scale structure formation can be modeled as a nonlinear process that transfers energy from the largest scales to successively smaller scales until it is dissipated, in analogy with Kolmogorov's cascade model of incompressible turbulence. However, cosmic turbulence is very compressible, and vorticity plays a secondary role in it. The simplest model of cosmic turbulence is the adhesion model, which can be studied perturbatively or adapting to it Kolmogorov's non-perturbative approach to incompressible turbulence. This approach leads to observationally testable predictions, e.g., to the power-law exponent of the matter density two-point correlation function.