Jeff drawn by Kay
portrait by Kay Erickson (2018)

I'm a computational geometer/topologist/graphophile with more general interests in algorithms, data structures, and lower bounds. I teach mostly large algorithms classes; you might find my free textbook and other course materials useful. Exactly half of my former PhD students have tenure. From 2013 to 2016, I was an associate department head and chair of the faculty recruiting committee. I am a SafeTOC advocate.

I have the lowest undergraduate GPA (2.4/4.0) of any professor I've ever met, although some of my colleagues came close, and a few others never finished college at all. (I really shouldn't be proud of that.) Only three other professors have been in my department longer than I have. (I really shouldn't be proud of that, either.)

Praxis tendatum docebit. [Practice will teach those who try.]
— Carl Friedrich Gauß, describing the fast Fourier transform (c. 1805)

Man muß jederzeit an Stelle von „Punkte, Geraden, Ebenen“ „Tische, Stühle, Bierseidel“ sagen können. [One must always be able to say “tables, chairs, beer mugs” in place of “points, lines, planes”.]
— David Hilbert to Otto Blumenthal, on the axiomatic method in mathematics

I believe in the third dimension, but not the other two.
James "Kibo" Parry

As we all know, the easiest way to be at the top of your field is to choose a very small field.
Simone Giertz, "Why you should make useless things" (2018)