Mathematica Bohemica (Dec 2021)

Homogenization of linear parabolic equations with three spatial and three temporal scales for certain matchings between the microscopic scales

  • Tatiana Danielsson,
  • Pernilla Johnsen

DOI
https://doi.org/10.21136/MB.2021.0087-19
Journal volume & issue
Vol. 146, no. 4
pp. 483 – 511

Abstract

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In this paper we establish compactness results of multiscale and very weak multiscale type for sequences bounded in $L^2(0,T;H_0^1(\Omega))$, fulfilling a certain condition. We apply the results in the homogenization of the parabolic partial differential equation $\varepsilon^p\partial_tu_{\varepsilon}(x,t) -\nabla\cdot( a( x\varepsilon^{-1} ,x\varepsilon^{-2},t\varepsilon^{-q},t\varepsilon^{-r}) \nabla u_{\varepsilon}(x,t) ) = f(x,t) $, where $0<p<q<r$. The homogenization result reveals two special phenomena, namely that the homogenized problem is elliptic and that the matching for which the local problem is parabolic is shifted by $p$, compared to the standard matching that gives rise to local parabolic problems.

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