Semilocal convergence for Halley's method under weak Lipschitz condition (Q1049319)

Let \(X,Y\) be Banach spaces, \(D\) be an open convex part of \(X\) and \(F:D\to Y\) be a continuous, twice Fréchet differentiable operator. The semilocal convergence of the Halley's method \[ x_{k+1}=x_k-(I-L_F(x_k))^{-1} F'(x_k)^{-1}F(x_k), \quad k\geq 0, \] towards the unique solution \(x^*\) of \(F(u)=0\) is established, under Lipschitz type assumptions involving the second derivative of \(F\).