2022-present: Provost and Senior Vice President for Academic Affairs, Ithaca College
2021-2022 (August-April): Interim Provost and Vice President for Academic Affairs, Ithaca College
2019-2021: Dean of the School of Humanities and Sciences, Ithaca College
2015-2019: Dean of Academic Affairs, Trinity College
2015-2016 (November-June): Interim Dean of the Faculty, Trinity College
2011-2014: Associate Academic Dean, Trinity College
2006-2008: Mathematics Department Chair, Trinity College
2019-present: Professor of Mathematics, Ithaca College
2010-2019: Professor of Mathematics, Trinity College
2001-2010: Associate Professor of Mathematics, Trinity College
1995-2001: Assistant Professor of Mathematics, Trinity College
1991-1992 and 1993-1995: Research Instructor, The Ohio State University
1992-1993: Visiting Scholar, Johann-Wolfgang-Goethe Universität in Frankfurt, Germany
1984-1991: Teaching Assistant, Cornell University
Ph.D. Cornell University, August 1991
M.S. Cornell University, January 1988
A.B. Harvard University, June 1983
Geometric group theory
AMS classification numbers 20F65, 20E08, 20E99, 57M60, 57M50
Automorphisms of Higher Rank Lamplighter Groups (with Jennifer Taback and Peter Wong), Internat. J. Algebra Comput. 25 (8) (2015) 1275-1299.
Metric Properties of Diestel-Leader Groups (with Jennifer Taback), Michigan Math. J.62 (2013) 365-386.
Free limits of Thompson’s Group F (with Azer Akhmedov and Jennifer Taback), Geom. Dedicata 155 (1) (2011) 163-176.
Tame Combings and Almost Convexity Conditions (with Sean Cleary, Susan Hermiller, and Jennifer Taback), Math. Z. 269 (3) (2011) 879-915.
A Note on the Convexity Properties of Thompson’s group F (with Matthew Horak and Jennifer Taback), J. Group Theory 15 (1) (2012) 37-45.
Computing word length in alternate presentations of Thompson’s group F (with Matthew Horak and Jennifer Taback), Internat. J. Algebra Comput. 19(3) (2009), 963-997.
Pure braid subgroups of braided Thompson’s groups (with T. Brady, J Burillo, S. Cleary), Publ. Mat.52 (2008), 57-89.
Partially Ordered Groups act on Oriented Order Trees (with Matthew Horak), Rocky MountainJ. Math. 40(5)(2010), 1527-1578.
Combinatorial and metric properties of Thompson’s Group T (with J. Burillo, S. Cleary, J. Taback), Trans. Amer. Math. Soc. 361 (2009), 631-652.
Infinitely Many Hyperbolic 3-manifolds which contain no Reebless Foliation (with R. Roberts and J. Shareshian), J. Amer. Math. Soc. 16(3) (2003), 639-679.
Group actions on order trees (with Rachel Roberts), Topology Appl. 115 (2001), 175-201.
Labeling Products of Complete Graphs with a Condition at Distance Two (with John P. Georges and David W. Mauro), SIAM J. Disc. Math. 14(1) (2000), 28-35.
Metrics and Embeddings of Generalizations of Thompson’s Group (with Jose Burillo and Sean Cleary), Trans. Amer. Math. Soc. 353(4) (2000), 1677-1689.
Exceptional Seifert group actions on R (with Rachel Roberts), J. Knot Theory Ramifications 8(2)(1999), 241-247.
Some problems in Geometric Group Theory (with M. Shapiro), Geometric Group Theory, Eds. Charney, Davis, Shapiro, de Gruyter & Co. (1995)
Almost Convex Groups and the Eight Geometries (with M. Shapiro), Geom. Dedicata 55 (1995), 125-140.
Groups of Piecewise Linear Homeomorphisms, Trans. Amer. Math. Soc. 332(2) (1992), 477-514.
September 25, 2016, AMS Special Session on Geometric Group Theory, Bowdoin College, “Automorphisms of higher rank lamplighter groups”
October 9, 2010, Approaches to Group Theory, Cornell University, “Combing the Cayley Complex for Thompson’s group F”
May 19, 2009, International Conference on Geometric and Combinatorial Methods in Group Theory and Semigroup Theory, University of Nebraska, Lincoln, NE, “A tame 1-combing for Thompson’s group F with linear tameness function”
November 11, 2008, Smith College, “How complicated is an Infinite Group?”
May 10, 2007, Bard College, Annandale-on-Hudson, NY, “Playing around in Thompson’s group F”
Dec 3, 2004: New York Group Theory Seminar, CUNY Graduate Center, NY, “Partially ordered groups which act on simply connected 1-manifolds”
March 11, 2003: Cornell University, “Establishing nonexistence of laminations and foliations in 3-manifolds using group actions on order trees”
April 25, 2002: Yale University, “Existence of laminations in 3-manifolds and fundamental group actions on order trees” January 2002: AMS Special Session on Low Dimensional Topology, San Diego, CA, “Hyperbolic 3-manifolds with no Reebless Foliations”
March 22, 2000: Topology Seminar at the Graduate Center, CUNY, “Group Actions on Order Trees and Laminations in 3-manifolds”
April 23, 1999: AMS Special Session on Knots and 3-manifolds, University of Buffalo, “Group Actions on Order Trees”
May 31, 1998: Nonpositive Curvature in Group Theory, Topology, and Geometry, Vanderbilt University, “Exceptional Seifert Group Actions on R”
Oct 16, 1994: SUNYA Topology and Group Theory Conference, SUNY at Albany, “Almost Convex Groups and the Eight Geometries”
American Mathematical Society