Renormalized waves and thermalization of the Klein-Gordon equation

We study the thermalization of the classical Klein-Gordon equation under a u[superscript 4] interaction. We numerically show that even in the presence of strong nonlinearities, the local thermodynamic equilibrium state exhibits a weakly nonlinear behavior in a renormalized wave basis. The renormaliz...

Full description

Bibliographic Details
Main Author: Shirokoff, David George
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:en_US
Published: American Physical Society 2011
Online Access:http://hdl.handle.net/1721.1/65874
_version_ 1826201522277449728
author Shirokoff, David George
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Shirokoff, David George
author_sort Shirokoff, David George
collection MIT
description We study the thermalization of the classical Klein-Gordon equation under a u[superscript 4] interaction. We numerically show that even in the presence of strong nonlinearities, the local thermodynamic equilibrium state exhibits a weakly nonlinear behavior in a renormalized wave basis. The renormalized basis is defined locally in time by a linear transformation and the requirement of vanishing wave-wave correlations. We show that the renormalized waves oscillate around one frequency, and that the frequency dispersion relation undergoes a nonlinear shift proportional to the mean square field. In addition, the renormalized waves exhibit a Planck-like spectrum. Namely, there is equipartition of energy in the low-frequency modes described by a Boltzmann distribution, followed by a linear exponential decay in the high-frequency modes.
first_indexed 2024-09-23T11:52:45Z
format Article
id mit-1721.1/65874
institution Massachusetts Institute of Technology
language en_US
last_indexed 2024-09-23T11:52:45Z
publishDate 2011
publisher American Physical Society
record_format dspace
spelling mit-1721.1/658742022-10-01T06:40:04Z Renormalized waves and thermalization of the Klein-Gordon equation Shirokoff, David George Massachusetts Institute of Technology. Department of Mathematics Shirokoff, David George Shirokoff, David George We study the thermalization of the classical Klein-Gordon equation under a u[superscript 4] interaction. We numerically show that even in the presence of strong nonlinearities, the local thermodynamic equilibrium state exhibits a weakly nonlinear behavior in a renormalized wave basis. The renormalized basis is defined locally in time by a linear transformation and the requirement of vanishing wave-wave correlations. We show that the renormalized waves oscillate around one frequency, and that the frequency dispersion relation undergoes a nonlinear shift proportional to the mean square field. In addition, the renormalized waves exhibit a Planck-like spectrum. Namely, there is equipartition of energy in the low-frequency modes described by a Boltzmann distribution, followed by a linear exponential decay in the high-frequency modes. Natural Sciences and Engineering Research Council of Canada (NSERC) National Science Foundation (U.S.) (grant DMS-0813648) 2011-09-16T18:04:15Z 2011-09-16T18:04:15Z 2011-04 2010-11 Article http://purl.org/eprint/type/JournalArticle 1539-3755 1550-2376 http://hdl.handle.net/1721.1/65874 Shirokoff, D. “Renormalized Waves and Thermalization of the Klein-Gordon Equation.” Physical Review E 83.4 (2011) : 046217 ©2011 American Physical Society en_US http://dx.doi.org/10.1103/PhysRevE.83.046217 Physical Review E Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS
spellingShingle Shirokoff, David George
Renormalized waves and thermalization of the Klein-Gordon equation
title Renormalized waves and thermalization of the Klein-Gordon equation
title_full Renormalized waves and thermalization of the Klein-Gordon equation
title_fullStr Renormalized waves and thermalization of the Klein-Gordon equation
title_full_unstemmed Renormalized waves and thermalization of the Klein-Gordon equation
title_short Renormalized waves and thermalization of the Klein-Gordon equation
title_sort renormalized waves and thermalization of the klein gordon equation
url http://hdl.handle.net/1721.1/65874
work_keys_str_mv AT shirokoffdavidgeorge renormalizedwavesandthermalizationofthekleingordonequation