JH
The basics
Quick facts
Intro
American mathematician
Gender:
Male
Places:
Work field:
Education:
University of California, Berkeley
The details
Biography
Introduction
Joel Hass is an American mathematician, a professor of mathematics and chair of the mathematics department at the University of California, Davis.
Biography
Hass received his Ph.D. from the University of California, Berkeley in 1981 under the supervision of Robion Kirby. He joined the Davis faculty in 1988.
In 2012 he became a fellow of the American Mathematical Society.
Research contributions
Hass is known for proving the equal-volume special case of the double bubble conjecture, for proving that the unknotting problem is in NP, and for giving an exponential bound on the number of Reidemeister moves needed to reduce the unknot to a circle.
Selected publications
- Research papers
- Freedman, Michael; Hass, Joel; Scott, Peter (1983), "Least area incompressible surfaces in 3-manifolds" (PDF), Inventiones Mathematicae, 71 (3): 609–642, Bibcode:1983InMat..71..609F, doi:10.1007/BF02095997, MR 0695910.
- Hass, Joel; Lagarias, Jeffrey C.; Pippenger, Nicholas (1999), "The computational complexity of knot and link problems", Journal of the ACM, 46 (2): 185–211, arXiv:math/9807016, doi:10.1145/301970.301971.
- Hass, Joel; Schlafly, Roger (2000), "Double bubbles minimize", Annals of Mathematics, Second Series, 151 (2): 459–515, arXiv:math/0003157, doi:10.2307/121042, MR 1765704.
- Hass, Joel; Lagarias, Jeffrey C. (2001), "The number of Reidemeister moves needed for unknotting", Journal of the American Mathematical Society, 14 (2): 399–428, arXiv:math/9807012, doi:10.1090/S0894-0347-01-00358-7, MR 1815217.
- Books
- Adams, Colin; Hass, Joel; Thompson, Abigail (1998), How to Ace Calculus: The Streetwise Guide, New York: W.H. Freeman and Company, ISBN 0-7167-3160-6.
- Adams, Colin; Hass, Joel; Thompson, Abigail (2001), How to Ace the Rest of Calculus: The Streetwise Guide, New York: W.H. Freeman and Company, ISBN 0-7167-4174-1.