The Dirichlet problem for nonuniformly elliptic equations
Neil S. Trudinger · Bulletin of the American Mathematical Society · 1967
Introduction. Let flbea bounded domain in E n . The operatoracting on functions ^(x)£C 2 (0) is elliptic in 0 if the minimum eigenvalue A(x, u, p) of the matrix [a ij '(x, u, p)] is positive in 0X£ n+1 .Here