South England Profinite Groups Meetings

Joint Research Group funded by LMS Scheme 3
Academic Year 2009-10

Background: In recent years profinite and asymptotic methods have been successfully applied to general problems of group theory. In addition there are interesting links to number theory and geometry.
Activities: During the academic year 2009-10 we are holding a series of three meetings in order to
- provide a platform for young mathematicians from across the south of England to meet and discuss their research in profinite groups, asymptotic group theory and related topics,
- get graduate students and postdoctoral fellows involved by giving them the opportunity to discuss and possibly present their individual work,
- give the participants an opportunity to widen their research horizons and their knowledge base by familiarising themselves with research adjacent to their own,
- foster and develop collaborative links both within the group and with selected experts from the UK and abroad.
Participants: We welcome and encourage interested mathematicians at all levels to join us in our meetings. The Joint Research Group receives financial support from the London Mathematical Society and has therefore limited funds to reimburse travel expenses of UK-based students and young mathematicians. Please contact the organisers if you wish to apply for such reimbursements.
Organisers: Corresponding organisers of the Joint Research Group are Benjamin Klopsch (Royal Holloway, University of London), Nikolay Nikolov (Imperial College London) and Christopher Voll (University of Southampton).

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Expansion in Groups

19-20 April 2010 at Imperial College London

Description: This two-day workshop will introduce newcomers to the rapidly evolving subject of expansion in groups and bring them to up to date with the latest results and methods in this area. It will stimulate discussions among all its participants, including leading experts in the field, and further research in this exciting area.
Expander graphs have proved to be an immensely useful concept, both in Pure Mathematics and in Computer Science. On the one hand they provide models for efficient and robust networks and very fast algorithms for solving computational problems. On the other hand expanders and, more generally, expansion properties in groups have been the subject of much recent research, involving tools from group theory, combinatorics, representation theory, analysis and number theory. Deep connections have emerged between expansion and properties of generating sets of simple groups, sum-product results in additive combinatorics, 3-dimensional topology and measurable group theory.
One cannot help but think that many profound results in this area are still to be discovered.
Location: Imperial College London
Date: 19-20 April 2010
Local Organiser: Nikolay Nikolov
Further Details: Workshop Webpage

Complete Calendar of Events

One-Day Meeting: Just Infinite Profinite Branch Groups

Description: The meeting will introduce newcomers to self-similar groups. It will then move on to recent results and open problems from a profinite perspective.
Location: Royal Holloway, University of London
Date: provisionally 12 December 2009
Local Organisers: Yiftach Barnea and Benjamin Klopsch

Two-Day Workshop: Expansion in Groups

Description: The workshop will bring together people with an exisitng or fresh interest in expander graphs and, more generally, expansion properties in groups. The latter have been the subject of much recent research, involving tools from group theory, combinatorics, representation theory, analysis and number theory.
Location: Imperial College London
Date: 19-20 April 2010
Local Organiser: Nikolay Nikolov
Further Details: Workshop Webpage

One-Day Meeting: The Kirillov Orbit Method

Description: The Kirillov orbit method and recent applications will be explained.
Location: Queen Mary College London
Date: provisionally 11 June 2010
Local Organiser: Anton Evseev

Past Meetings

Just Infinite Profinite Branch Groups

12 December 2009 at Royal Holloway (University of London)

Description: The meeting will introduce newcomers to self-similar groups. It will then move on to recent results and open problems from a profinite perspective.
There will be three talks and one problem session with breaks for discussions. The programme will start at about 11:30 and it will end at about 17:15. Click here for a printable programme and here for a printable poster.
12.00 - 13.00 Branch groups: theory and practice (John Wilson)
13.00 - 14.00 Sandwich Lunch
14.00 - 15.00 Some branch group constructions (Dan Segal)
15.30 - 16.30 Profinite groups generated by automata (Laurent Bartholdi)
16.45 - 17.00 Open Problems (Laurent Bartholdi, Dan Segal, John Wilson et al.)
Location: Royal Holloway, University of London, McCrea Building, Room 219
Date: Saturday, 12 December 2009
Local Organisers: Yiftach Barnea and Benjamin Klopsch
Practical Information: The meeting will take place in the McCrea Building, Room 219. For a Campus plan, other maps and travel directions follow the respective link from the College's Visitor Guide.
Resources: L. Bartholdi, R. I. Grigorchuk, Z. Sunik: Branch Groups, available here.
L. Bartholdi, O. Siegenthaler: The Twisted Twin of the Grigorchuk Group, available here.
L. Bartholdi, O. Siegenthaler, P. Zalesskii: The congruence subgroup problem for branch groups, available here.
D. Segal: The finite images of finitely generated groups, Proc. London Math. Soc. (3) 82 (2001), no. 3, 597--613, available here.
J.S. Wilson: Structure theory for branch groups, in: Geometric and Cohomological Methods in Group Theory (edited by M.R. Bridson e.a.), London Mathematical Society Lecture Note Series (No. 358), Cambridge University Press, 2009; see here.
Further suggestions will be posted in due course.

For past meetings during the academic year 2008-09 click here.

For past meetings during the academic year 2007-08 click here.

last significant update 18.02.2010
please bring corrections to the attention of Benjamin Klopsch