[C script]^sup [alpha]^-regularity for a class of non-diagonal elliptic systems with p-growth

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) We consider weak solutions to nonlinear elliptic systems in a W ^sup 1,p^-setting which arise as Euler equations to certain variational problems. The solutions are assumed to be stationary in the sense that the differential of the variational integral vanishes with respect to variations of the dependent and independent variables. We impose new structure conditions on the coefficients which yield everywhere [C script]^sup α^-regularity and global [C script]^sup α^-estimates for the solutions. These structure conditions cover variational integrals like ... with potential ... and positively definite quadratic forms in ... Since the Q ^sub i^ need not to be linearly dependent our result covers a class of nondiagonal, possibly nonmonotone elliptic systems. The proof uses a new weighted norm technique with singular weights in an L ^sup p^-setting.[PUBLICATION ABSTRACT]