Boundary corrector in periodic homogenization (source code)

= Boundary corrector in periodic homogenization
{title2=$b^\epsilon|_{\partial\Omega}=-\epsilon w_j(x/\epsilon)\partial_j u_0$}

A bulk cell expansion generally leaves an oscillatory Dirichlet mismatch. A boundary corrector can solve the homogeneous oscillatory conductivity equation with boundary data cancelling that mismatch. It restores the prescribed physical boundary <trace> while leaving the leading bulk cell formula unchanged. Estimates depend on boundary regularity and on the coefficient assumptions.