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Jiancong Xiao

8 accepted papers

2026

Statistical Impossibility and Possibility of Aligning LLMs with Human Preferences: From Condorcet Paradox to Nash Equilibrium

ICML 2026poster

Aligning large language models (LLMs) with diverse human preferences is critical for ensuring fairness and informed outcomes when deploying these models for decision-making. In this paper, we seek to uncover fundamental statistical limits concerning aligning LLMs with human preferences, with a focus…

Cited by 0SourcecodeScholar
2025

Fine-Tuning Attention Modules Only: Enhancing Weight Disentanglement in Task Arithmetic

ICLR 2025poster

In recent years, *task arithmetic* has garnered increasing attention. This approach edits pre-trained models directly in weight space by combining the fine-tuned weights of various tasks into a *unified model*. Its efficiency and cost-effectiveness stem from its training-free combination, contrastin…

Cited by 1SourcePDFScholar
2025

Magnetic Preference Optimization: Achieving Last-iterate Convergence for Language Model Alignment

ICLR 2025poster

Self-play methods have demonstrated remarkable success in enhancing model capabilities across various domains. In the context of Reinforcement Learning from Human Feedback (RLHF), self-play not only boosts Large Language Model (LLM) performance but also overcomes the limitations of traditional Bradl…

Cited by 3SourcePDFScholar
2025

Preserving Diversity in Supervised Fine-Tuning of Large Language Models

ICLR 2025poster

Large Language Models (LLMs) typically rely on Supervised Fine-Tuning (SFT) to specialize in downstream tasks, with the Cross Entropy (CE) loss being the de facto choice. However, CE maximizes the likelihood of observed data without accounting for alternative possibilities. As such, CE usually lead…

Cited by 0SourcePDFScholar
2025

Restoring Calibration for Aligned Large Language Models: A Calibration-Aware Fine-Tuning Approach

ICML 2025poster

One of the key technologies for the success of Large Language Models (LLMs) is preference alignment. However, a notable side effect of preference alignment is poor calibration: while the pre-trained models are typically well-calibrated, LLMs tend to become poorly calibrated after alignment with huma…

Cited by 0SourcePDFScholar
2024

Uniformly Stable Algorithms for Adversarial Training and Beyond

ICML 2024poster

In adversarial machine learning, neural networks suffer from a significant issue known as robust overfitting, where the robust test accuracy decreases over epochs (Rice et al., 2020). Recent research conducted by Xing et al., 2021;Xiao et al., 2022 has focused on studying the uniform stability of ad…

2023

PAC-Bayesian Spectrally-Normalized Bounds for Adversarially Robust Generalization

NeurIPS 2023poster

Deep neural networks (DNNs) are vulnerable to adversarial attacks. It is found empirically that adversarially robust generalization is crucial in establishing defense algorithms against adversarial attacks. Therefore, it is interesting to study the theoretical guarantee of robust generalization. Thi…

Cited by 11SourcePDFScholar
2022

Stability Analysis and Generalization Bounds of Adversarial Training

NeurIPS 2022accept

In adversarial machine learning, deep neural networks can fit the adversarial examples on the training dataset but have poor generalization ability on the test set. This phenomenon is called robust overfitting, and it can be observed when adversarially training neural nets on common datasets, includ…