arXiv subjects

J. J. Ye

Publications and source records attributed to J. J. Ye.

3 recordsLinked to original sources

arXiv2026

Second-order optimality conditions for optimization problems with generalized equation constraints

This paper provides second-order optimality conditions for optimization problems with generalized equation constraints (GEPs), a framework that encompasses several important and challenging models in mathematical programming, including mathematical programs with variational inequality constraints (MPVIs) and bilevel programs. The obtained optimality conditions are novel even for these particular problem classes. As an application, second-order optimality conditions for MPVIs are detailed. The technical key lies in developing first- and second-order variational analysis of the highly intricate constraint system, which is needed to capture the local curvature of the feasible set entering these optimality conditions. Part of this task was already carried out in our companion paper \cite{BeGfrYeZhangZhou}, and here we complete the study. Comprehensive variational analysis results are derived, which are of independent interest.

math.OC↗

arXiv2023

Sensitivity analysis of the maximal value function with applications in nonconvex minimax programs

In this paper, we perform sensitivity analysis for the maximal value function which is the optimal value function for a parametric maximization problem. Our aim is to study various subdifferentials for the maximal value function. We obtain upper estimates of Fréchet, limiting, and horizon subdifferentials of the maximal value function by using some sensitivity analysis techniques sophisticatedly. The derived upper estimates depend only on the union of all solutions and not on its convex hull or only one solution from the solution set. Finally, we apply the derived results to develop some new necessary optimality conditions for nonconvex minimax problems. In the nonconvex-concave setting, our Wolfe duality approach compare favourably with the first order approach in that the necessary condition is sharper and the constraint qualification is weaker.

math.OC↗

arXiv2022

Laboratory observation of plasmoid-dominated magnetic reconnection in hybrid collisional-collisionless regime

Magnetic reconnection, breaking and reorganization of magnetic field topology, is a fundamental process for rapid release of magnetic energy into plasma particles that occurs pervasively throughout the universe. In most natural circumstances, the plasma properties on either side of the reconnection layer are asymmetric, in particular for the collision rates that are associated with a combination of density and temperature and critically determine the reconnection mechanism. To date, all laboratory experiments on magnetic reconnections have been limited to purely collisional or collisionless regimes. Here, we report a well-designed experimental investigation on asymmetric magnetic reconnections in a novel hybrid collisional-collisionless regime by interactions between laser-ablated Cu and CH plasmas. We show that the growth rate of the tearing instability in such a hybrid regime is still extremely large, resulting in rapid formation of multiple plasmoids, lower than that in the purely collisionless regime but much higher than the collisional case. In addition, we, for the first time, directly observe the topology evolutions of the whole process of plasmoid-dominated magnetic reconnections by using highly-resolved proton radiography.

physics.plasm-ph↗