Differentiabilty and partial hölder continuity of solutions of nonlinear elliptic systems

The authors continue the study of regularity properties for solutions of elliptic systems started in [19] and continued [20], proving, in a bounded open set Ω. of ℝ n, local differentiability and partial Hölder continuity of the weak solutions u of nonlinear elliptic systems of order 2m in divergence form ∑, (-1)| α| Dαa α(x, Du) = 0. a≤m Specifically, we generalize the results obtained by Campanato and Cannarsa, contained in [6], under the hypothesis that the coefficients a α(x, Du) are strictly monotone with nonlinearity 9 = 2. © Heldermann Verlag.