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Diffusive Propagation of Energy in a Non-Acoustic Chain

Mathematical Physics 2016-08-24 v1 Statistical Mechanics math.MP Probability

Abstract

We consider a non acoustic chain of harmonic oscillators with the dynamics perturbed by a random local exchange of momentum, such that energy and momentum are conserved. The macroscopic limits of the energy density, momentum and the curvature (or bending) of the chain satisfy a system of evolution equations}. We prove that, in a diffusive space-time scaling, the curvature and momentum evolve following a linear system that corresponds to a damped Euler-Bernoulli beam equation. The macroscopic energy density evolves following a non linear diffusive equation. In particular the energy transfer is diffusive in this dynamics. This provides a first rigorous example of a normal diffusion of energy in a one dimensional dynamics that conserves the momentum.

Keywords

Cite

@article{arxiv.1601.02123,
  title  = {Diffusive Propagation of Energy in a Non-Acoustic Chain},
  author = {Tomasz Komorowski and Stefano Olla},
  journal= {arXiv preprint arXiv:1601.02123},
  year   = {2016}
}