Henry Wilton

I am an R. H. Bing Instructor at the University of Texas at Austin. You can find me in room RLM 10.140. My principal areas of research include Sela's limit groups, subgroup separability, the logic of free groups and other areas of geometric group theory. You can find out more about my research here.

All my articles, notes and slides are in pdf format, so you can view them using Acrobat Reader.

Last autumn I visited the MSRI for their Geometric Group Theory programme. Lars Louder and I took notes on Zlil Sela's course on definable sets in free groups. In their current, incomplete state they can be found here.

Teaching

For the Spring 2008 semester, I am teaching M408D Differential and Integral Calculus and M341 Linear Algebra and Matrix Theory. Both courses are administered through Blackboard.

In the Spring 2007 semester, I taught M427K Advanced Calculus for Applications I. Material from courses that I have taught before is available here.

Papers

• Subgroup separability in residually free groups (with Martin R. Bridson). To appear in Math. Z.
• Hall's Theorem for limit groups. To appear in GAFA.
• Elementarily free groups are subgroup separable, Proc. London Math. Soc., 95(2) (2007), pp. 473-496.
• Limit groups, positive-genus towers and measure equivalence
  (with Martin R. Bridson and Michael Tweedale), Ergod. Th. Dynam. Sys. 27 (2007), pp. 703-712.
• Subgroup separability of limit groups. PhD thesis, University of London (2006).
• Solutions to Bestvina & Feighn's exercises on limit groups. To appear in Geometry and Cohomology in Group Theory (Durham, 2003).

Preprints

Here is an ArXiv search for me.

• Residually free 3-manifolds. Preprint (2008).
• Conjugacy classes of solutions to equations and inequations over hyperbolic groups (with Daniel Groves). Preprint (2007).
• Enumerating limit groups (with Daniel Groves). Preprint (2007).

Notes

• My Part III essay on The Geometrization Conjecture
• The Rips Machine

Talks

This is a list of some talks that I've given. Some of them have accompanying notes or slides, of variable quality. E-mails pointing out typos and other errors are appreciated.

• A structure theory for limit groups and Positive-genus towers (Geometry, Topology and Dynamics Seminar, UIC, April 2008)
• Computing solutions to systems of equations over free and hyperbolic groups (Groups and Dynamics Seminar, Texas A&M, March 2008)
• Computing solutions to systems of equations over free and hyperbolic groups (Groups and Dynamics Seminar, Texas A&M, March 2008)
• Computing solutions to systems of equations over free and hyperbolic groups (AMS Sectional Meeting, Baton Rouge, March 2008)
• Residually free 3-manifolds (Topology Seminar, Rice, March 2008)
• Residually free 3-manifolds (Topology Seminar, UT Austin, February 2008)
• Hall's Theorem for limit groups (Caen, July 2007)
• Hall's Theorem for limit groups (Paris-Sud 11, Orsay, July 2007)
• Limit groups, LERF and local retractions (Geometry & Topology Seminar, Caltech, February 2007)
• Limit groups are LERF (Topology Seminar, UT Austin, October 2006)
• Some residual properties of groups (AMS Sectional Meeting, University of Utah, October 2006)
• Some residual properties of groups (Amitsur Algebra Colloquium, Hebrew University of Jerusalem, April 2006)
• Limit groups, measure equivalence and subgroup separability (Geometry, Integrable Systems and Topology, University of Glasgow, January 2006)
• Subgroup separability and limit groups (London Algebra Colloquium, November 2005)
• At the Geometric Topology conference at Będlewo in July 2005, Lars Louder and I gave a series of recitations to accompany Mladen Bestvina's workshop on limit groups. Here are the slightly illegible handwritten notes from recitations I and III. (Będlewo, July 2005)
• An Introduction to Limit Groups (Series for Telgiggy, Imperial College, London, January 2005)

I also have notes/slides for graduate talks on An Introduction to Geometrization, Group actions on trees, Algebraic geometry over groups, Bass-Serre theory and Hyperbolic spaces, R-trees and outer automorphisms.

Conferences

• Asymptotic Group Theory (Jerusalem, May 2006)
• Geometric and Topological Methods in Group Theory (Oberwolfach, April 2006)
• Geometric topology (Będlewo, July 2005)
• Geometric group theory (Będlewo, April 2004)
• Hodge theory in a new century (Edinburgh, July 2003)
• Geometry and cohomology in group theory (LMS colloquium, Durham, July 2003)

Other mathematicians

These are links to the web pages of some other mathematicians: my mathematical family, colleagues, collaborators, housemates etc.

• My thesis supervisor, Martin Bridson, Imperial College, London
• My doctorbruder, Michael Tweedale, University of Bristol
• Alan Reid, UT Austin
• Dannyel Groves, CalTech
• Ben Klaff, UT Austin
• David "Ben" McReynolds, CalTech