Scott Armstrong, Alexandre Bordas and Jean-Christophe
Mourrat
Vol. 11 (2018), No. 8, 1945–2014
DOI: 10.2140/apde.2018.11.1945
Abstract
We develop a quantitative theory of stochastic homogenization for linear, uniformly
parabolic equations with coefficients depending on space and time. Inspired by recent
works in the elliptic setting, our analysis is focused on certain subadditive quantities
derived from a variational interpretation of parabolic equations. These subadditive
quantities are intimately connected to spatial averages of the fluxes and gradients of
solutions. We implement a renormalization-type scheme to obtain an algebraic rate
for their convergence, which is essentially a quantification of the weak convergence of
the gradients and fluxes of solutions to their homogenized limits. As a consequence,
we obtain estimates of the homogenization error for the Cauchy–Dirichlet
problem which are optimal in stochastic integrability. We also develop a higher
regularity theory for solutions of the heterogeneous equation, including a uniform
-type
estimate and a Liouville theorem of every finite order.