Algebra Kinderseminar
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Wed, 28/04/2010 11:30 |
David Craven (University of Oxford) |
Algebra Kinderseminar  |
ChCh, Tom Gate, Room 2 |
| There are two competing notions for a normal subsystem of a (saturated) fusion system. A recent theorem of mine shows how the two notions are related. In this talk I will discuss normal subsystems and their properties, and give some ideas on why this might be useful or interesting. | |||
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Wed, 05/05/2010 11:30 |
Plamen Kochloukov (Universidade Estadual de Campinas) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
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Wed, 12/05/2010 11:30 |
Elisabeth Fink (University of Oxford) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
| I'll start with the definition of the first Grigorchuk group as an automorphism group on a binary tree. After that I give a short overview about what growth means, and what kinds of growth we know. On this occasion I will mention a few groups that have each kind of growth and also outline what the 'Gap Problem' was. Having explained this I will prove - or depending on the time sketch - why this Grigorchuk group has intermediate growth. Depending on the time I will maybe also mention one or two open problems concerning growth. | |||
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Wed, 19/05/2010 11:30 |
Owen Cotton-Barratt (University of Oxford) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
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Wed, 26/05/2010 11:30 |
(University of Oxford) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
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Wed, 02/06/2010 11:30 |
Amaia Zugadi Reizabal (Euskal Herriko Unibertsitatea) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
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Wed, 09/06/2010 11:30 |
Dawid Kielak (University of Oxford) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
| We will introduce both the classical Hanna Neumann Conjecture and its strengthened version, discuss Stallings' reformulation in terms of immersions of graphs, and look at some partial results. If time allows we shall also look at the new approach of Joel Friedmann. | |||
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Wed, 16/06/2010 11:30 |
Jason Semeraro (University of Oxford) |
Algebra Kinderseminar |
ChCh, Tom Gate, Room 2 |
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Not only does the definition of an (abstract) saturated fusion system provide us with an interesting way to think about finite groups, it also permits the construction of exotic examples, i.e. objects that are non-realisable by any finite group. After recalling the relevant definitions of fusion systems and saturation, we construct an exotic fusion system at the prime 3 as the fusion system of the completion of a tree of finite groups. We then sketch a proof that it is indeed exotic by appealing to The Classification of Finite Simple Groups. |
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