Achiya Dax

1 Introduction minimize F ( x ) = 1 2 ‖ A x − b ‖ 2 2 , $$ \operatorname{minimize}\kern0.3em \hspace{2.56804pt}F\left(\mathbf{x}\right)=\frac{1}{2}{\left\Vert A\mathbf{x}-\mathbf{b}\right\Vert}_2^2, $$ (1) In this article, we consider the use of restarted Krylov methods for solving linear least squares problems of the form A ∈ ℝ m × n , b ∈ ℝ m , and ‖ · ‖ 2 $$ A\in {\mathbb{R}}^{m\times n},\kern3.0235pt \hspace{0.3em}\mathbf{b}\in {\mathbb{R}}^m,\kern9.07pt \mathrm{and}\kern9.07pt...