Conjugator length, (pdf)
GAGTA / Cornell / Binghamton, 2025/26
Fractional Distortion in Hyperbolic Groups, (pdf)
Bob Gilman's 80th Birthday Conference, Stevens Institute, 2023
Screwball Conjectures, (pdf)
Cambridge Colloquium, 2019
Dehn functions, the word problem, hydra, and magical salmon, (pdf)
GAGTA, 2016
Hyperbolic groups, Cannon-Thurston Maps, and hydra, (Quicktime Movie)
Warwick Colloquium, 2014
Lamplighters, metabelian groups, and horocyclic products, (Quicktime Movie)
GAGTA, CCNY, 2013
Big numbers, graph coloring, and Hercules' battle with the hydra, (pdf)
K–12 Education and Outreach, Cornell, 2011
The Dehn function of Baumslag's metabelian group, (pdf)
Binghamtom, Geometry & Topology Seminar, 2011
Hydra Groups, (pdf)
What is a Dehn function? (pdf)
"What is..." Seminar, Cornell 2009
What is amenability? (pdf)
Introductory talk, Bristol–Oxford–Southampton Network in Geometric and Analytic Methods in Group Theory, 2009
How wild can a group with quadratic Dehn function be? (pdf)
Workshop on Boundaries, Graz, June 2009
The geometry of discs spanning loops in groups and spaces, (pdf)
Cornell Topology Festival, 2007
Geometric notions of space complexity for the word problem, (pdf)
Combinatorial and Geometric Group Theory, Vanderbilt, 2006
Intrinsic versus extrinsic diameter in finitely presented groups, (pdf)
Asymptotic and Probabilistic Methods in Geometric Group Theory, Geneva,2005
Diameters of Cayley graphs of SL_n(Z/kZ), (pdf)
Geometric Group Theory, Barcelona, 2005
Navigating in the Cayley graphs of SL_N(Z) and SL_N(F_p), (pdf)
Albany Group Theory Conference, 2004
Support from the U.S. National Science Foundation under Grants No. DMS0540830 (2004–2007), DMS1101651 (2011–2014), and GCR2428489 (2024–) is gratefully acknowledged. Any opinions, findings, and conclusions or recommendations expressed in these web pages are those of the author and do not necessarily reflect the views of the National Science Foundation.