A new semilocal convergence theorem for Newton's method

Abstract A new semilocal convergence theorem for Newton's method is established for solving a nonlinear equation F ( x ) = 0, defined in Banach spaces. It is assumed that the operator F is twice Frechet differentiable, and F ″ satisfies a Lipschitz type condition. Results on uniqueness of solution and error estimates are also given. Finally, these results are compared with those that use Kantorovich conditions.