``We are here and it is now. Further than that all human knowledge is moonshine.'' -- H.L. Mencken


David G. Wagner

Department of Combinatorics and Optimization
Faculty of Mathematics
University of Waterloo
Waterloo, Ontario, Canada
N2L 3G1


Handles








Before enlightenment
chopping wood
carrying water

After enlightenment
chopping wood
carrying water



Combinatorics of electrical networks

Notes for a series of lectures prepared for the Undergraduate Summer Research Assistants of the C&O Department in 2009.


Multivariate stable polynomials: theory and applications

A survey of the recent work of Julius Borcea and Petter Br"and'en on their multivariate generalization of the theory of univariate polynomials with only real roots, and its applications. This includes a very short (but complete!) account of Gurvits's proof of the van der Waerden Conjecture. Commissioned by the AMS for the Current Events Bulletin at the San Francisco meeting in January, 2010.


``Unfortunately, in mathematics philosophy is permanently condemned to play second fiddle to algebra.'' -- Gian-Carlo Rota



CO 739 Combinatorics of Partially Ordered Sets

Homepage for CO 739 in Fall 2009.


CO 330 Combinatorial Enumeration

Homepage for CO 330 in Fall 2009.


``The trouble with the rat race is that, even if you win, you're still a rat.'' -- Lili Tomlin


MoonShot Applet

Ever wanted to fly a rocket to the Moon and back? Here's an amusing little time-waster.



``In the fight between you and the world, back the world.'' -- Frank Zappa



``Pay no attention to critics. No statue was ever put up for a critic.'' -- Jean Sibelius



I stumped Google.