A new existence theorem for an elliptic equation with discontinuous and non-differentiable coefficients (Q1113361)

We prove a theorem of existence in \(R^ n\) of periodic solutions of an elliptic equation whose coefficients are periodic functions locally of class \(W^{(\mu -1)/\mu,\mu},\) with \(\mu\geq 6\) and independent on n. The known term is assumed to be a bounded periodic function locally of class \(W^{1/2,2}\).