# Steve Butler

## Email: butler@iastate.edu

## Office: Carver 420 (currently working from home)

## YouTube Channel ISMaRT

Steve Butler is a professor and the * Barbara J. Janson Professor* in the Department of Mathematics at Iowa State University. Prior to coming to Iowa State he did a three year NSF PostDoc under the supervision of Benny Sudakov at UCLA. Before that he earned his doctorate degree in mathematics at UC San Diego under the supervision of Fan Chung. In addition he has worked extensively with Ron Graham.

His primary mathematical interests are spectral graph theory, enumerative combinatorics, mathematics of juggling, discrete geometry, and generally mathematics of fun things. Among other things, he can do eight perfect faro shuffles in a row, and is willing to teach this to anyone who stops by his office.

From Fall of 2018 through Fall of 2020 Steve was the calculus coordinator for Iowa State University.

Published in June 2018 by Cambridge University Press is a book I edited -- *Connections in Discrete Mathematics**.*

One of my main areas of research is spectral graph theory. A graph looks at the connections (edges) between objects (vertices). One way to understand a graph is by storing it as an array. A linear algebraist sees an array and says "Hey, let's call it a matrix" (matrix = array with benefits), and then a whole new world of exploration opens up by looking at the eigenvalues of the matrix, and this is the area of spectral graph theory.

I have worked in mathematics of juggling (currently one of only a few mathematicians who have published more papers about the mathematics of juggling than the number of balls that they can juggle).

Coming in the near(?) future from Princeton University Press -- *Juggling Counts*

I have a lot of fun working with students; and a few of the students have had a lot of fun and been creative with me. You can find a few of the videos online:

## In the news:

Performing at the Iowa State Fair in 2017.

Becoming the last Erdős number one in 2015.

A mathematics of juggling class taught in 2013.

With Ron Graham