activity
20192026
most citedInstance-Dependent Complexity of Contextual Bandits and Reinforcement Learning: A Disagreement-Based Perspective

23 citations · 34 across the 10 of their papers we have counts for

collaborators

10 papers

math.OC2026

Online Control via Counterfactual Tracking

Yunzong Xu

We study online control of a known linear dynamical system with adversarial costs and bounded disturbances, measuring regret against a general class of benchmark policies. We intro…

math.PR2026

Finite-Time Queue Peak Laws in Stochastic Networks: Logarithmic Scaling After Geometric Thresholds

Hao Liang, Cheng Tang, Yunzong Xu

We study finite-horizon queue peaks in generalized switches, a standard stochastic-network model in which many queues share constrained service resources. Arrivals may be dependent…

cs.LG2026

Optimal Hidden-Target Learning for Online Inventory Optimization on General Convex Sets

Anthony Pineci, Yunzong Xu

Online inventory optimization (OIO) is online convex optimization with physical memory: inventory carryover makes the feasible action set depend on the past. A natural principle, u…

cs.LG2025

Greedy Algorithm for Structured Bandits: A Sharp Characterization of Asymptotic Success / Failure

Aleksandrs Slivkins, Yunzong Xu, Shiliang Zuo

We study the greedy (exploitation-only) algorithm in bandit problems with a known reward structure. We allow arbitrary finite reward structures, while prior work focused on a few s…

cs.LG2021★ 3 cited

Offline Reinforcement Learning: Fundamental Barriers for Value Function Approximation

Dylan J. Foster, Akshay Krishnamurthy, David Simchi-Levi +1

We consider the offline reinforcement learning problem, where the aim is to learn a decision making policy from logged data. Offline RL -- particularly when coupled with (value) fu…

cs.LG2020★ 23 cited

Instance-Dependent Complexity of Contextual Bandits and Reinforcement Learning: A Disagreement-Based Perspective

Dylan J. Foster, Alexander Rakhlin, David Simchi-Levi +1

In the classical multi-armed bandit problem, instance-dependent algorithms attain improved performance on "easy" problems with a gap between the best and second-best arm. Are simil…

cs.LG2020

Bypassing the Monster: A Faster and Simpler Optimal Algorithm for Contextual Bandits under Realizability

David Simchi-Levi, Yunzong Xu

We consider the general (stochastic) contextual bandit problem under the realizability assumption, i.e., the expected reward, as a function of contexts and actions, belongs to a ge…

cs.LG2019★ 3 cited

Blind Network Revenue Management and Bandits with Knapsacks under Limited Switches

David Simchi-Levi, Yunzong Xu, Jinglong Zhao

This paper studies the impact of limited switches on resource-constrained dynamic pricing with demand learning. We focus on the classical price-based blind network revenue manageme…

cs.LG2019★ 1 cited

Online Pricing with Offline Data: Phase Transition and Inverse Square Law

Jinzhi Bu, David Simchi-Levi, Yunzong Xu

This paper investigates the impact of pre-existing offline data on online learning, in the context of dynamic pricing. We study a single-product dynamic pricing problem over a sell…

cs.LG2019★ 4 cited

Phase Transitions in Bandits with Switching Constraints

David Simchi-Levi, Yunzong Xu

We consider the classical stochastic multi-armed bandit problem with a constraint that limits the total cost incurred by switching between actions to be no larger than a given swit…