About Me

I am a first-year PhD student studying theoretical computer science (TCS) in CMU, co-advised by William Kuszmaul and Guy Blelloch. I completed my Bachelor’s degree in Yao Class, Tsinghua University.

I mainly work on classical data structures, especially hash tables and succinct data structures. I also work on fast matrix multiplication.

Selected Publications

• More Asymmetry Yields Faster Matrix Multiplication
  with Josh Alman, Ran Duan, Virginia Vassilevska Williams, Yinzhan Xu, and Zixuan Xu
  In SODA 2025
• Tight Bounds and Phase Transitions for Incremental and Dynamic Retrieval
  with William Kuszmaul, Aaron Putterman, Tingqiang Xu, and Hangrui Zhou
  In SODA 2025
• Tight Bounds for Classical Open Addressing
  with Michael A. Bender and William Kuszmaul
  In FOCS 2024
• New Bounds for Matrix Multiplication: from Alpha to Omega
  with Virginia Vassilevska Williams, Yinzhan Xu, and Zixuan Xu
  In SODA 2024
  Covered in Quanta Magazine
• Dynamic Dictionary with Subconstant Wasted Bits per Key
  with Tianxiao Li, Jingxun Liang, and Huacheng Yu
  In SODA 2024
• Dynamic “Succincter”
  with Tianxiao Li, Jingxun Liang, and Huacheng Yu
  In FOCS 2023
• Tight Cell-Probe Lower Bounds for Dynamic Succinct Dictionaries
  with Tianxiao Li, Jingxun Liang, and Huacheng Yu
  In FOCS 2023
  Covered in Quanta Magazine
• Faster Matrix Multiplication via Asymmetric Hashing
  with Ran Duan and Hongxun Wu
  In FOCS 2023
  Covered in Quanta Magazine

Misc

Chinese name: 周任飞
Pronunciation of my name: Renfei [ˈrɛnˌfeɪ], Zhou [ˈʒoʊ]. Sounds like “Ren-fay Joe”.
Sports: ping-pong, cycling (had a trip from Hangzhou to Beijing, 1700km on bike)
Erdős number: 4