“…where f : R d → R is smooth and strongly self-concordant. Quasi-Newton methods [2,3,4,6,8,33,36] are widely recognized for their fast convergence rates and efficient updates, which attracts growing attention in many fields such as statistics [1,16,37], economics [20,24] and machine learning [12,15,19,22,23]. Unlike standard Newton methods which need to compute the Hessian and its inverse, quasi-Newton methods go along the descent direction by the following scheme…”