A sharp estimate a la calderon-zygmund for the p--laplacian
  We consider local weak solutions of the Poisson equation for the p--Laplace operator. We prove a higher differentiability result, under an essentially sharp condition on the right-hand side. The result comes with a local scaling invariant a priori estimate. 
Lorenzo Brasco (DPT OF MATH., UNIV. OF FERRARA, I2M), Filippo   Santambrogio (LM-Orsay)
math.AP