Solvability of the Neumann Problem in a Disk for Fourth-Order Properly Elliptic Equations

Resumo

We establish and study sufficient conditions of solvability of the Neumann problem for fourth-order properly elliptic equations of the general form in a unit disk K in the space \( {C}^4(K)\cap {C}^{3,\upalpha}\left(\overline{K}\right) \).