I am a postdoctoral researcher at Department of Statistics & Data Science, Carnegie Mellon University, hosted by Dr. Kathryn Roeder and Dr. Jing Lei.

I received my PhD (2022) from Department of Biostatistics, University of Washington. My dissertation advisor was Dr. Noah Simon. Before graduate school, I double-majored in biology and math at Peking University (2013-17). I also worked on business-motivated problems at Amazon and FOXO Technologies.

I will join PSTAT at the University of California, Santa Barbara in Fall 2025.

Research Interests

I’m interested in developing statistical learning methods that are computationally scalable, grounded in solid theory, and robust in practice, including:

• Nonparametric methods (e.g., basis expansions, reproducing kernels, and shape-constrained estimation)
• Model selection techniques (especially cross-validation and its variants)
• Online estimation with streaming data
• Single-cell RNA sequencing analysis (both novel scientific questions and methodological developments)

Publications

A complete list of my publications is available in my CV.

Software

Most of my methodology works have a companion R package. I also mix in some C++ to improve the computational efficiency when needed. It is hard to keep the package information up-to-date in peer-reviewed publications so I list them here for your ease of reference.

argminCS. Github. Tutorial (Hao Lee is the developer of this package):

Tianyu Zhang, Hao Lee, and Jing Lei. “Winners with confidence: Discrete argmin inference with an application to model selection”.

Sieve. R CRAN:

Tianyu Zhang and Jing Lei. “Online Estimation with Rolling Validation: Adaptive Nonparametric Estimation with Streaming Data.”
Tianyu Zhang and Noah Simon. “A Sieve Stochastic Gradient Descent Estimator for Online Nonparametric Regression in Sobolev Ellipsoids.”

HMC. R CRAN. Tutorial (co-developed with Ergan Shang):

Tianyu Zhang, Jing Lei, and Kathryn Roeder. “Debiased Projected Two-Sample Comparisonscfor Single-Cell Expression Data.”

Joint-Lassosum. Github (with L. Klei and P. Liu as lead contributors):

Tianyu Zhang, Geyu Zhou, Lambertus Klei, Peng Liu, Alexandra Chouldechova, Hongyu Zhao, Kathryn Roeder, Max G’Sell, and Bernie Devlin. “Evaluating and Improving Health Equity and Fairness of Polygenic Scores.”