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Xuchuang Wang

14 accepted papers

2026

A Multi-Agent Conversational Bandit Approach to Online Evaluation and Selection of User-Aligned LLM Responses

AAAI 2026technical

Prompt-based offline methods are commonly used to optimize large language model (LLM) responses, but evaluating these responses is computationally intensive and often fails to accommodate diverse response styles. This study introduces a novel online evaluation framework that employs a multi-agent co

Cited by 0SourcePDFScholar
2025

Federated Multi-armed Bandits with Efficient Bit-Level Communications

NeurIPS 2025poster

In this work, we study the federated multi-armed bandit (FMAB) problem, where a set of distributed agents collaboratively aim to minimize cumulative regret while interacting with a shared set of arms. Unlike traditional centralized bandit models, agents in FMAB settings are connected via a communica…

Cited by 0SourceScholar
2025

Fusing Reward and Dueling Feedback in Stochastic Bandits

ICML 2025poster

This paper investigates the fusion of absolute (reward) and relative (dueling) feedback in stochastic bandits, where both feedback types are gathered in each decision round. We derive a regret lower bound, demonstrating that an efficient algorithm may incur only the smaller among the reward…

Cited by 0SourcePDFScholar
2025

Heterogeneous Multi-Agent Bandits with Parsimonious Hints

AAAI 2025technical

We study a hinted heterogeneous multi-agent multi-armed bandits problem (HMA2B), where agents can query low-cost observations (hints) in addition to pulling arms. In this framework, each of the M agents has a unique reward distribution over K arms, and in T rounds, they can observe the reward of the…

Cited by 0SourcePDFScholar
2025

Near-Optimal Regret Bounds for Federated Multi-armed Bandits with Fully Distributed Communication

UAI 2025

In this paper, we focus on the research of federated multi-armed bandit (FMAB) problems where agents can only communicate with their neighbors. All agents aim to solve a common multi-armed bandit (MAB) problem to minimize individual regrets, while group regret can also be minimized. In a federated b

Cited by 0SourcePDFScholar
2025

Quantum Best Arm Identification with Quantum Oracles

AAAI 2025technical

Best arm identification (BAI) is a key problem in stochastic multi-armed bandits, where K arms each has an associated reward distribution, and the objective is to minimize the number of queries needed to identify the best arm with high confidence. In this paper, we explore BAI using quantum oracles.…

Cited by 0SourcePDFScholar
2025

Stochastic Bandits Robust to Adversarial Attacks

ICLR 2025poster

This paper investigates stochastic multi-armed bandit algorithms that are robust to adversarial attacks, where an attacker can first observe the learner's action and *then* alter their reward observation. We study two cases of this model, with or without the knowledge of an attack budget $C$, define…

Cited by 0SourcePDFScholar
2024

Combinatorial Multivariant Multi-Armed Bandits with Applications to Episodic Reinforcement Learning and Beyond

ICML 2024poster

We introduce a novel framework of combinatorial multi-armed bandits (CMAB) with multivariant and probabilistically triggering arms (CMAB-MT), where the outcome of each arm is a $d$-dimensional multivariant random variable and the feedback follows a general arm triggering process. Compared with exist…

Cited by 4SourcePDFScholar
2023

Achieving Near-Optimal Individual Regret & Low Communications in Multi-Agent Bandits

ICLR 2023poster

Cooperative multi-agent multi-armed bandits (CM2AB) study how distributed agents cooperatively play the same multi-armed bandit game. Most existing CM2AB works focused on maximizing the group performance of all agents---the accumulation of all agents' individual performance (i.e., individual reward)…

Cited by 13SourcePDFScholar
2023

Exploration for Free: How Does Reward Heterogeneity Improve Regret in Cooperative Multi-agent Bandits?

UAI 2023poster

This paper studies a cooperative multi-agent bandit scenario in which the rewards observed by agents are heterogeneous—one agent’s meat can be another agent’s poison. Specifically, the total reward observed by each agent is the sum of two values: an arm-specific reward, capturing the intrinsic value…

Cited by 2SourcePDFScholar
2023

On-Demand Communication for Asynchronous Multi-Agent Bandits

AISTATS 2023poster

This paper studies a cooperative multi-agent multi-armed stochastic bandit problem where agents operate asynchronously – agent pull times and rates are unknown, irregular, and heterogeneous – and face the same instance of a K-armed bandit problem. Agents can share reward information to speed up the…

Cited by 10SourcePDFScholar
2022

Multi-Player Multi-Armed Bandits with Finite Shareable Resources Arms: Learning Algorithms & Applications

IJCAI 2022poster

Multi-player multi-armed bandits (MMAB) study how decentralized players cooperatively play the same multi-armed bandit so as to maximize their total cumulative rewards. Existing MMAB models mostly assume when more than one player pulls the same arm, they either have a collision and obtain zero rewar…

Cited by 10SourcePDFScholar
2022

Multiple-Play Stochastic Bandits with Shareable Finite-Capacity Arms

ICML 2022spotlight

We generalize the multiple-play multi-armed bandits (MP-MAB) problem with a shareable arms setting, in which several plays can share the same arm. Furthermore, each shareable arm has a finite reward capacity and a “per-load” reward distribution, both of which are unknown to the learner. The reward f…

Cited by 10SourcePDFScholar