# Joel Hass

Distinguished Professor

Geometry and topology

Ph.D., 1981, University of California, BerkeleyWeb Page: http://www.math.ucdavis.edu/~hass/

Email: hass@math.ucdavis.edu

Office: MSB 2222

Current Courses: MAT 21A, MAT 216

Office Hours: W 11:10-1:00 (21A) online, F 12:10-1:00 (216) online

### Research

- Shape analysis

- Three dimensional manifolds
- Computational complexity

- Computational geometry and topology

- Differential geometry
- Minimal surfaces and bubbles

### Selected publications

- J. Hass and R. Schlafly. " Double Bubbles Minimize,"
*Annals of Mathematics*,**151**: 459-515, 2000, matharXiv0003.5157. - J. Hass and J. Lagarias, " The number of Reidemeister moves needed for unknotting,"
*J. Amer. Math. Soc.*,**14**(2): 399-428, 2001, matharXiv9807.5012. - J. Hass, I. Agol, and W.P. Thurston, " The Computational Complexity of Knot Genus and Spanning Area,"
*Trans. Amer. Math. Soc.*,**358**: 3821-3850, (2005). matharXiv0205.5057. - P Koehl, J Hass, Landmark-free geometric methods in biological shape analysis, Journal of The Royal Society Interface 12 (2015).
- C Even-Zohar, J Hass, N Linial, T Nowik, Invariants of random knots and links, Discrete & Computational Geometry 56 (2), 274-314 (2016).

### Books

- How to Ace Calculus: The Streetwise Guide, by Colin Conrad Adams, Joel Hass, Abigail Thompson. WH Freeman & Co., September, 1998.
- How to Ace the Rest of Calculus: The Streetwise Guide, by Colin Conrad Adams, Joel Hass, Abigail Thompson. WH Freeman & Co., September, 2001.
- Proceedings of the Kirbyfest. Held in Berkeley, CA, June 22-26, 1998. Edited by Joel Hass and Martin Scharlemann. Geometry & Topology Monographs, 2. Geometry & Topology Publications, Coventry, 1999. front matter+569 pp. (electronic). 57-06 (00B30).
- Thomas’ Calculus, 14th edition (with Thomas, Weir, Heil) Pearson, 2017.
- Thomas’ Calculus, 14th edition ET (with Thomas, Weir, Heil) Pearson, 2017.
- University Calculus, 4th edition (with Thomas, Heil, Bogacki), Addison-Wesley, 2019.

*Last updated: 2019-10-26*