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Qiwei Di

10 accepted papers

2026

Best-of-Majority: Minimax-Optimal Strategy for Pass@k Inference Scaling

ICLR 2026poster

LLM inference often generates a batch of candidates for a prompt and selects one via strategies like majority voting or Best-of- N (BoN). For difficult tasks, this single-shot selection often underperforms. Consequently, evaluations commonly report Pass@$k$: the agent may submit up to $k$ responses,…

Cited by 0SourceScholar
2026

Dimension-Independent Convergence of Underdamped Langevin Monte Carlo in KL Divergence

ICML 2026poster

Underdamped Langevin dynamics (ULD) is a widely-used sampler for Gibbs distributions $\pi\propto e^{-V}$, and is often empirically effective in high dimensions. However, existing non-asymptotic convergence guarantees for discretized ULD typically scale polynomially with the ambient dimension $d$, le…

Cited by 0SourceScholar
2026

On the Limits of Test-Time Compute: Sequential Reward Filtering for Better Inference

ICML 2026poster

Test-time compute (TTC) has become an increasingly prominent paradigm for enhancing large language models (LLMs). Despite the empirical success of methods such as best-of-$n$ (BoN) sampling and sequential revision, their fundamental limits remain unclear. We address this gap by analyzing a mixture-o…

Cited by 0SourceScholar
2025

Nearly Optimal Algorithms for Contextual Dueling Bandits from Adversarial Feedback

ICML 2025poster

Learning from human feedback plays an important role in aligning generative models, such as large language models (LLM). However, the effectiveness of this approach can be influenced by adversaries, who may intentionally provide misleading preferences to manipulate the output in an undesirable or ha…

Cited by 2SourcePDFScholar
2025

Unified Convergence Analysis for Score-Based Diffusion Models with Deterministic Samplers

ICLR 2025poster

Score-based diffusion models have emerged as powerful techniques for generating samples from high-dimensional data distributions. These models involve a two-phase process: first, injecting noise to transform the data distribution into a known prior distribution, and second, sampling to recover the o…

Cited by 3SourcePDFScholar
2024

Borda Regret Minimization for Generalized Linear Dueling Bandits

ICML 2024poster

Dueling bandits are widely used to model preferential feedback prevalent in many applications such as recommendation systems and ranking. In this paper, we study the Borda regret minimization problem for dueling bandits, which aims to identify the item with the highest Borda score while minimizing t…

Cited by 13SourcePDFScholar
2024

Pessimistic Nonlinear Least-Squares Value Iteration for Offline Reinforcement Learning

ICLR 2024poster

Offline reinforcement learning (RL), where the agent aims to learn the optimal policy based on the data collected by a behavior policy, has attracted increasing attention in recent years. While offline RL with linear function approximation has been extensively studied with optimal results achieved u…

Cited by 9SourcePDFScholar
2024

Variance-aware Regret Bounds for Stochastic Contextual Dueling Bandits

ICLR 2024poster

Dueling bandits is a prominent framework for decision-making involving preferential feedback, a valuable feature that fits various applications involving human interaction, such as ranking, information retrieval, and recommendation systems. While substantial efforts have been made to minimize the cu…

2023

Nearly Minimax Optimal Regret for Learning Linear Mixture Stochastic Shortest Path

ICML 2023poster

We study the Stochastic Shortest Path (SSP) problem with a linear mixture transition kernel, where an agent repeatedly interacts with a stochastic environment and seeks to reach certain goal state while minimizing the cumulative cost. Existing works often assume a strictly positive lower bound of th…

Cited by 2SourcePDFScholar