We present a new method for the large-scale trust-region subproblem. The method is matrix-free in the sense that only matrix-vector products are required. We recast the trust-region subproblem as a parameterized eigenvalue problem and compute an optimal value for the parameter. We then find the solution of the trust-region subproblem from the eigenvectors associated with two of the smallest eig...

In the paper, aimed at the shortcoming of trust region method, we proposed a algorithm using negative curvature direction as its searching direction. The convergence of the algorithm was given. Furthermore, combing trust region method and curve-linear searching techniques, a trust region algorithm, using general curvelinear searching direction, was proposed. We proved its efficiency and feasibi...