collaborators

10 papers

math.OC2026

Wasserstein Robust Performative Prediction via Lagrangian Relaxation

Siyi Wang, Zifan Wang, Karl H. Johansson

In machine learning, predictive models are trained on historical data. Their deployment may incentivize agents to strategically adapt their behavior, thereby inducing a model-depen…

cs.GT2026

A Scenario Approach to the Robustness of Nonconvex-Nonconcave Minimax Problems

Huan Peng, Guanpu Chen, Karl Henrik Johansson

This paper investigates probabilistic robustness of nonconvex-nonconcave minimax problems via the scenario approach. Specifically, under convex strategy sets for all players, inspi…

cs.LG2026

Efficient Tail-Aware Generative Optimization via Flow Model Fine-Tuning

Zifan Wang, Riccardo De Santi, Xiaoyu Mo +3

Fine-tuning pre-trained diffusion and flow models to optimize downstream utilities is central to real-world deployment. Existing entropy-regularized methods primarily maximize expe…

math.OC2025

Risk-Averse Learning with Varying Risk Levels

Siyi Wang, Zifan Wang, Karl H. Johansson

In safety-critical decision-making, the environment may evolve over time, and the learner adjusts its risk level accordingly. This work investigates risk-averse online optimization…

cs.RO2025

SparScene: Efficient Traffic Scene Representation via Sparse Graph Learning for Large-Scale Trajectory Generation

Xiaoyu Mo, Jintian Ge, Zifan Wang +2

Multi-agent trajectory generation is a core problem for autonomous driving and intelligent transportation systems. However, efficiently modeling the dynamic interactions between nu…

math.OC2025

Wasserstein Distributionally Robust Nash Equilibrium Seeking with Heterogeneous Data: A Lagrangian Approach

Zifan Wang, Georgios Pantazis, Sergio Grammatico +2

We study a class of distributionally robust games where agents are allowed to heterogeneously choose their risk aversion with respect to distributional shifts of the uncertainty. I…