Hello! I’m Haolin, a 6th year PhD candidate in the Department of Statistics at Columbia University. I am fortunately advised by Dr. Arian Maleki and Prof. Victor de la Peña. Before my doctoral study, I received my Master in Actuarial Science from Columbia University in 2020. I received my Bachelor in Applied Mathematics and Bachelor in Economics from Peking University in 2018.

My Research Interests

I have a broad interest in using high dimensional statistical theory to understand current machine learning methods and developing new algorithms, with a primary focus on proportional high dimensional asymptotics. My current research focuses on:

1. Risk estimation and cross validation methods,
2. Machine unlearning,
3. Data evaluation and interpretability

Selected Publications

Publications

1. Zou, H., Auddy, A., Kwon, Y., Rahnama Rad, K. and Maleki, A. (2025). Certified Machine Unlearning Under High Dimensional Regime. Accepted by Journal of Machine Learning Research (JMLR).
2. Zou, H. et al. (2025). Newfluence: Boosting Model Interpretability and Understanding in High Dimensions. ICML 2025, Workshop: Assessing World Models: Methods and Metrics for Evaluating Understanding.
3. Zou, H. et al. (2025). Theoretical Analysis of Leave-one-out Cross Validation for Non-differentiable Penalties under High-dimensional Settings._ Proceedings of The 28th International Conference on Artificial Intelligence and Statistics_, PMLR 258:4033-4041.
4. Auddy, A., Zou, H., Rahnama Rad, K. and Maleki, A. (2024) Approximate Leave-one-out Cross Validation for Regression with L1 Regularizers. IEEE Transactions on Information Theory, 70(11):8040–8071.
5. Auddy, A., Zou, H., Rahnama Rad, K. and Maleki, A. (2024) Approximate Leave-one-out Cross Validation for Regression with L1 Regularizers. Proceedings of The 27th International Conference on Artificial Intelligence and Statistics, PMLR 238:2377-2385. Selected for oral presentation.
6. Baydil, B., de la Peña, V., Zou, H. and Yao, H. (2025). Unbiased estimation of the Gini coefficient. Statistics and Probability Letters, 222:110376.
7. de la Peña, V., Gzyl, H., Mayoral, S., Zou, H. and Alemayehu, D. (2024). Prediction and estimation of random variables with infinite mean or variance. Communications in Statistics - Theory and Methods, 54(1):1-15.

Working Papers

1. Zou, H., Auddy, A., Rahnama Rad, K. and Maleki, A. (2025). Error Analysis of K-fold Cross Validation Under High-dimensional Settings.

Under Review

1. Zou, H., Yao, H. and de la Peña, V. (2025). A Scalable Formula for the Moments of a Family of Self-Normalized Statistics. Submitted to Statistics and Probability Letters.
2. Pandey, A., Auddy, A., Zou, H., Maleki, A. and Kulkarni, S. (2025). Gaussian Certified Unlearning in High Dimensions: A Hypothesis Testing Approach. Submitted to ICLR 2026.