math.OC cs.CC 49M37, 65K05, 68Q17, 68W40, 90C30 F.2.1; G.1.6; I.1.2
Refining asymptotic complexity bounds for nonconvex optimization methods, including why steepest descent is $o(ε^{-2})$ rather than $\mathcal{O}(ε^{-2})$
Serge Gratton Chee-Khian Sim Philippe L. Toint