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Haoxian Chen

haoxian.chen (at) columbia.edu


Short Bio

I am an Applied Scientist at Amazon, where I focus on agentic AI and time series foundation models.

I received my Ph.D. in Operations Research from Columbia University, where I was fortunate to be advised by Prof. Henry Lam and Prof. Wenpin Tang. Prior to that, I completed a B.S. in Applied Mathematics from UCLA.

My research interests center on generative modeling (LLMs and diffusion models) with a focus on RLHF and alignment, as well as efficient uncertainty quantification. I am particularly motivated by designing algorithms that combine efficiency with rigorous theoretical guarantees. Previously, I collaborated with Prof. Krzysztof Choromanski on efficient Transformers and random features.

News

[Jan 2026] Our paper ToKUR is accepted to ICLR 2026!
[May 2025] Our paper Score as Action is accepted to ICML 2025.
[Mar 2025] Released RPO: A new method for fine-tuning T2I models using rich feedback generated by VLMs.
[Jan 2025] Our paper MallowsPO is accepted to ICLR 2025.
[Dec 2024] New preprint on enhancing Monte Carlo methods via machine learning, based on my research at Morgan Stanley.
[Jun 2024] Start my internship as an ML Research PhD intern at Morgan Stanley, Machine Learning Research.
[Jun 2023] Start my internship as an Applied Scientist intern at Amazon, SCOT Forecasting.
[Dec 2022] Awarded the 2023 Amazon CAIT Fellowship.

Selected Publications [ Google Scholar ]

  1. Hanyang Zhao*, Haoxian Chen*, Yucheng Guo*, Genta Indra Winata, Tingting Ou, Ziyu Huang, David D Yao, Wenpin Tang
    Arxiv

  2. Hanyang Zhao, Haoxian Chen, Ji Zhang, David D Yao, Wenpin Tang
    ICML 2025

  3. Fengpei Li*, Haoxian Chen*, Jiahe Lin*, Arkin Gupta, Xiaowei Tan, Gang Xu, Yuriy Nevmyvaka, Agostino Capponi, Henry Lam
    Major Revision at Management Science

  4. Haoxian Chen*, Hanyang Zhao*, Henry Lam, David Yao, Wenpin Tang
    ICLR 2025

  5. Haoxian Chen, Henry Lam
    Arxiv

  6. Krzysztof Choromanski*, Han Lin*, Haoxian Chen*, Tianyi Zhang, Arijit Sehanobish, Valerii Likhosherstov, Jack Parker-Holder, Tamas Sarlos, Adrian Weller, Thomas Weingarten
    ICML 2022

  7. Krzysztof Choromanski*, Haoxian Chen*, Han Lin*, Yuanzhe Ma*, Arijit Sehanobish*, Deepali Jain, Michael S Ryoo, Jake Varley, Andy Zeng, Valerii Likhosherstov, Dmitry Kalashnikov, Vikas Sindhwani, Adrian Weller
    ICLR 2022

  8. Haoxian Chen, Ziyi Huang, Henry Lam, Huajie Qian, Haofeng Zhang
    AISTATS 2021

  9. Han Lin*, Haoxian Chen*, Krzysztof M Choromanski, Tianyi Zhang, Clement Laroche
    NeurIPS 2020