In  J. Neuberger gave various sufficient conditions for the solvability of nonvariational operator equations via a variant of the steepest descent method. In this note we give versions of these conditions under weaker assumptions on the smoothness of the operators.
© 1985 Houston Journal of Mathematics
Alfonso Castro. “On the steepest descent for nonpotential locally Lipschitzian vector fields,” Houston J. of Math., Vol 11(1985), pp. 45-48.