Error estimate and unfolding for periodic homogenization
This provides a theoretical error estimate for periodic homogenization, relevant to mathematicians working on multiscale problems.
The paper establishes an upper bound for the distance between the unfolded gradient of a function in H1(Ω) and a specific space, using periodic unfolding methods, without requiring additional regularity hypotheses on correctors.
This paper deals with the error estimate in problems of periodic homogenization. The methods used are those of the periodic unfolding. We give the upper bound of the distance between the unfolded gradient of a function belonging to $H1(Ω)$ and the space $\nabla_x H^1(Ω)\oplus \nabla_y L^2(Ω; H^1_{per}(Y))$. These distances are obtained thanks to a technical result presented in Theorem 2.3: the periodic defect of a harmonic function belonging to $H1(Y)$ is written with the help of the norms $H^{1/2}$ of its traces diff erences on the opposite faces of the cell $Y$. The error estimate is obtained without any supplementary hypothesis of regularity on correctors.