{ "id": "1501.04238", "version": "v1", "published": "2015-01-17T22:34:33.000Z", "updated": "2015-01-17T22:34:33.000Z", "title": "Nonequilibrium statistical mechanics of weakly stochastically perturbed system of oscillators", "authors": [ "A. Dymov" ], "comment": "51 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "We consider a finite region of a $d$-dimensional lattice, $d\\in\\mathbb{N}$, of weakly coupled harmonic oscillators. The coupling is provided by a nearest-neighbour potential (harmonic or not) of size $\\varepsilon$. Each rotator weakly interacts by force of order $\\varepsilon$ with its own stochastic Langevin thermostat of arbitrary positive temperature. We investigate limiting as $\\varepsilon\\rightarrow 0$ behaviour of solutions of the system and of the local energy of oscillators on long-time intervals of order $\\varepsilon^{-1}$ and in a stationary regime. We show that it is governed by an effective equation which is a dissipative SDE with nondegenerate diffusion. Next we assume that the interaction potential is of size $\\varepsilon\\lambda$, where $\\lambda$ is another small parameter, independent from $\\varepsilon$. Solutions corresponding to this scaling describe small law temperature oscillations. We prove that in a stationary regime, under the limit $\\varepsilon\\rightarrow 0$, the main order in $\\lambda$ of the averaged Hamiltonian energy flow is proportional to the gradient of temperature. We show that the coefficient of proportionality, which we call the conductivity, admits a representation through stationary space-time correlations of the energy flow. Most of the results and convergences we obtain are uniform with respect to the number of oscillators in the system.", "revisions": [ { "version": "v1", "updated": "2015-01-17T22:34:33.000Z" } ], "analyses": { "subjects": [ "82C05", "82C70" ], "keywords": [ "weakly stochastically perturbed system", "nonequilibrium statistical mechanics", "oscillators", "stationary regime", "small law temperature oscillations" ], "note": { "typesetting": "TeX", "pages": 51, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150104238D" } } }