Associate Professor, Department of Mathematics, Western University

I have been in the math
department at the University of Western Ontario since 2002. I
received my PhD at the University
of Michigan in 1999.

My mathematical interests fit roughly under a heading of algebraic
combinatorics. More precisely, this includes arrangements of
hyperplanes and subspaces, combinatorial aspects of rational homotopy
theory, and "toric topology."

I have some preprints and publications available here.

- Math 3152a/9043a Combinatorial mathematics.
- Math 1600a Linear Algebra.

- Math 3157 Introduction to Game Theory.

- Topology of Arrangements and Representation Stability, Oberwolfach, 14-20 January 2018, coorganized with Giovanni Gaiffi (Pisa), Rita Jimenez Rolland (Oaxaca), and Alex Suciu (Boston).
- Arrangements of Hypersurfaces, an AMS special session at the 2018 Spring Eastern Meeting, April 21-22, 2018, Northeastern University, Boston, MA. Coorganized with Alex Suciu.

- CAAC 2016, Western, 22-24 January 2016, coorganized with Nicole Lemire
(Western) and Hugh Thomas (UQAM), a three-day meeting in algebraic
combinatorics and its interactions with algebraic geometry and
commutative algebra. (The abstracts page has slides from some of the talks.)

- Combinatorial Constructions in Topology, University of Regina, August 17-21, 2015, coorganized with Soumen Sarkar, Don Stanley (U. Regina) and Alex Suciu (Northeastern University). See the abstracts page for slides from some of the talks.
- Differential
and Combinatorial Aspects of Singularities, TU Kaiserslautern,
coorganized with Mathias
Schulze, Christian
Sevenheck, Uli
Walther, August 3-7, 2015. See the abstracts page for the slides from some of the talks.

- Computational Geometric Topology in Arrangement Theory, ICERM (Providence, RI), July 6-10, 2015, with Nero Budur, Dani Matei, Laurentiu Maxim, Hal Schenck, and Max Wakefield.

- A focussed research group Hyperplane Arrangements, Wonderful Compactifications, and Tropicalization at BIRS, with June Huh and Alex Suciu, April 2014.
- Cohomology Rings and Fundamental Groups of Hyperplane Arrangements, Wonderful Compactifications, and Real Toric Varieties at the Mathematisches Forschungsinstitut Oberwolfach, with Alex Suciu, October 2012.
- An AMS special session "The Algebraic Geometry and Topology of Hyperplane Arrangements" at the AMS spring sectional meeting in Worcester, MA, April 9-10, 2011, preceded by a workshop at Northeastern University on April 8, with Alex Suciu.
- A Conference in Honour of Peter Orlik at the Fields Institute in Toronto, with Dan Cohen and Nicole Lemire, August 2008.

I am a fan of Macaulay 2 (software for commutative algebra and algebraic geometry). Greg Smith and I have written a package for computation with hyperplane arrangements. It is included with the standard Macaulay 2 distribution (versions ≥ 1.0).

I was on sabbatical from July 2009 -- June 2010: I visited the EPFL (Lausanne) from September through November, and the University of Oregon from January through summer 2010.