Ryan Williams

Associate Professor
32 Vassar St, Cambridge, MA 02139

Email: first and middle initials + my last name at gmail.com

Previously I was a professor at Stanford for five years. I got a PhD from Carnegie Mellon under the marvelous Manuel Blum, and I was an undergrad at Cornell.
For more, see my CV below.
Teaching in Fall 2018 at UC Berkeley:
CS 294-152. Lower Bounds: Beyond the Bootcamp

(In conjunction with the Simons Institute program on Lower Bounds)


Past Teaching:

Research Interests

In general, I try to understand what is easy and what is hard to compute (independently of any particular computer). I work in algorithm design and complexity theory, and I especially like connections between the two subjects. I think about many questions, but a few of them haunt me more than others. Some examples: Can the existence of an algorithm for a problem be used to prove that other algorithms cannot exist for other problems? Can the nonexistence of algorithms be used to prove that another algorithm correctly solves a problem? (In fact, there are "yes" answers to both questions!) Does every function implementable with a low memory footprint also have a fast implementation? (Is $P = PSPACE$?) Could computers themselves help us make progress on answering these questions?

Current PhD Students

Brynmor Chapman
Josh Alman
Dylan McKay
Lijie Chen
Nikhil Vyas

Graduated PhD Students

Cody Murray (now: Research Fellow at Simons Institute, UC Berkeley)
Huacheng Yu (now: Postdoc at Harvard)


Michael Forbes (now: Tenure-track at UIUC)

About Me

I grew up near the big city of Somerville, Alabama, where there is good fishing in the water and good football on the radio. Further south in Alabama there is a good school for math and science.