On the kinetic description of the objective molecular dynamics

Richard D. James; Kunlun Qi; Li Wang

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arXiv · 2307.16814

On the kinetic description of the objective molecular dynamics

Richard D. James·Kunlun Qi·Li Wang

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Abstract

In this paper, we develop a multiscale hierarchy framework for objective molecular dynamics (OMD), a reduced order molecular dynamics with a certain symmetry, that connects it to the statistical kinetic equation, and the macroscopic hydrodynamic model. In the mesoscopic regime, we exploit two interaction scalings that lead, respectively, to either a mean-field type or to a Boltzmann type equation. It turns out that, under the special symmetry of OMD, the mean-field scaling results in vastly simplified dynamics that extinguishes the underlying molecular interaction rule, whereas the Boltzmann scaling yields a meaningful reduced model called the homo-energetic Boltzmann equation. At the macroscopic level, we derive the corresponding Euler and Navier-Stokes systems by conducting a detailed asymptotic analysis. The symmetry again significantly reduces the complexity of the resulting hydrodynamic systems.

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Richard D. James, Kunlun Qi, Li Wang. 2023-07-31. On the kinetic description of the objective molecular dynamics. https://arxiv.org/abs/2307.16814

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