Research

Papers and Preprints

1. Optimizing Chain-of-Thought Reasoners via Gradient Variance Minimization in Rejection Sampling and RL
   Jiarui Yao*, Yifan Hao*, Hanning Zhang, Hanze Dong, Wei Xiong, Nan Jiang, Tong Zhang, NeurIPS 2025.
   

2. Understanding Overadaptation in Supervised Fine-Tuning: The Role of Ensemble Methods
   Yifan Hao*, Xingyuan Pan*, Hanning Zhang*, Chenlu Ye, Rui Pan, Tong Zhang, ICML 2024.
   

3. Towards Better Generalization via Distributional Input Projection Network
   Yifan Hao*, Yanxin Lu*, Hanning Zhang, Xinwei Shen, Tong Zhang, Preprint.
   

4. Transformers as Multi-task Learners: Decoupling Features in Hidden Markov Models
   Yifan Hao*, Chenlu Ye*, Chi Han, Tong Zhang, Preprint.
   

5. Efficient Model Editing with Task Vector Bases: A Theoretical Framework and Scalable Approach
   Siqi Zeng, Yifei He, Weiqiu You, Yifan Hao, Yao-Hung Hubert Tsai, Makoto Yamada, Han Zhao, Preprint.
   

6. On the Benefits of Over-parameterization for Out-of-Distribution Generalization
   Yifan Hao*, Yong Lin*, Difan Zou, Tong Zhang, Preprint.
   

7. The Surprising Harmfulness of Benign Overfitting for Adversarial Robustness
   Yifan Hao, Tong Zhang, Preprint.
   

8. Spurious feature diversification improves out-of-distribution generalization
   Yong Lin*, Lu Tan*, Yifan Hao*, Honam Wong, Hanze Dong, Weizhong Zhang, Yujiu Yang, Tong Zhang, ICLR 2024.
   

9. Monte Carlo Sampling without Isoperimetry: A Reverse Diffusion Approach
   Xunpeng Huang*, Hanze Dong*, Yifan Hao, YI-An Ma, Tong Zhang, ICLR 2024.
   

10. SFQRA: Scaled Factor-augmented Quantile Regression with Aggregation in Conditional Mean Forecasting
    Lei Shu, Yifan Hao, Yu Chen, Qing Yang, Journal of Multivariate Analysis.
    

(* denotes equal contribution.)