Energy cascades and condensation via coherent dynamics in Hamiltonian systems

TL;DR

This paper analytically investigates energy cascades in Hamiltonian systems, revealing two types of cascade solutions that lead to large-scale condensates and structures, characterized by power-law spectra and singularities.

Contribution

It introduces two new analytically solvable Hamiltonian systems exhibiting distinct energy cascade behaviors and structure formations in turbulence.

Findings

Identification of two cascade solutions in Hamiltonian systems.

Formation of condensates and large-scale structures.

Development of power-law spectra leading to singularities.

Abstract

This work makes analytic progress in the deterministic study of turbulence in Hamiltonian systems by identifying two types of energy cascade solutions and the corresponding large- and small-scale structures they generate. The first cascade represents condensate formation via a highly coherent process recently uncovered, while the second cascade, which has not been previously observed, leads to the formation of other large-scale structures. The concentration of energy at small scales is characterized in both cases by the development of a power-law spectrum in finite time, causing the blow-up of Sobolev norms and the formation of coherent structures at small scales. These structures approach two different types of singularities: a point discontinuity in one case and a cusp in the other. The results are fully analytic and explicit, based on two solvable families of Hamiltonian systems identified in this study.