Co-authored by Professor Xu Zhang and Dr. Haisen Zhang who graduated from School of Mathematics in 2014, the research paper titled Pointwise Second-Order Necessary Conditions for Stochastic Optimal Controls, Part I: The Case of Convex Control Constraint has been re-published as the SIGEST Paper in Siam Review’s first edition of 2018. “Haisen Zhang and Xu Zhang, Pointwise second-order necessary conditions for stochastic optimal controls, Part I: The case of convex control constraint, SIAM J. Control Optim., 53 (2015), 2267—2296” .

By means of Malliavin calculus, this research paper has developed new techniques to establish pointwise second-order necessary conditions for stochastic optimal controls. SIAM Review chief editor has the following remarks: “The new techniques developed in these works pave the way for research that investigates other issues concerning high-order optimality conditions for stochastic control.”

As the flagship journal of the Society for Industrial and Applied Mathematics (SIAM), Siam Review is a quarterly. It features only one research paper each edition in order to draw attention to “outstanding paper of general interest”. SIAM has 17 specialized research journals. Each journal nominates a paper to the editorial committee and the editorial committee will select one as SIGEST paper for each edition.

Founded in 1959, SIAM Review deems a SIGEST Paper as a prize, and announces this paper and its authors in SIAM News every year. Prior to the paper by professor Xu Zhang and his team, the only other SIGEST Paper by a mainland China scholar was a research paper by Lei Guo and two other researchers.