Representation Theory Seminar
|
Thu, 12/05/2011 14:30 |
Alison Parker (Leeds) |
Representation Theory Seminar  |
L3 |
In joint work with Karin Baur (ETH, Zurich) and Karin Erdmann (Oxford),
we study certain Delta-filtered modules for the Auslander
algebra of k[T]/T^n\rtimes C_2 where C_2 is the cyclic group
of order two.
The motivation of this lies in the problem of describing the  -orbit
structure for the action of a parabolic subgroup of a linear algebraic
group on its nilradical \mathfrak{n}. In general, there are
infinitely P-orbits in \mathfrak{n} and it is a “wild” problem to describe them.
However, in the case of a parabolic subgroup of SL_N, there
exists a bijection between P-orbits in the nilradical and
certain (Delta-filtered) modules for the Auslander algebra of k[T]/T^n,
due to work of Hille and Rohrle and Brustle et al..
Under this bijection, the Richardson orbit (i.e. the
dense orbit) corresponds to the Delta-filtered module without
self-extensions.
It has remained an open problem to describe such
a correspondence for other classical groups. |
|||
|
Thu, 19/05/2011 14:30 |
Roozbeh Hazrat (Belfast) |
Representation Theory Seminar |
L3 |
|
Thu, 26/05/2011 14:30 |
R.C. King (Southampton) |
Representation Theory Seminar |
L3 |
|
Thu, 02/06/2011 14:00 |
Sira Gratz (ETH Zurich, Oxford) |
Representation Theory Seminar |
L3 |
| First lecture of Bloc meeting | |||
|
Thu, 02/06/2011 15:00 |
Chris Gill (Oxford) |
Representation Theory Seminar |
L3 |
|
Second lecture of Bloc meeting |
|||
|
Thu, 02/06/2011 16:30 |
Ed Green (Virginia Tech) |
Representation Theory Seminar |
L2 |
| Last lecture of Bloc meeting | |||
|
Thu, 09/06/2011 14:30 |
David Evans (Cardiff) |
Representation Theory Seminar |
L3 |
| Subfactor theory provides a framework for studying modular invariant partition functions in conformal field theory, and candidates for exotic modular tensor categories and almost Calabi-Yau algebras. I will survey some joint work with Terry Gannon and Mathew Pugh. | |||
|
Thu, 09/06/2011 17:00 |
Robert Boltje (Santa Cruz) |
Representation Theory Seminar |
L2 |
|
Thu, 16/06/2011 14:30 |
Delphine Dupont (Oxford) |
Representation Theory Seminar |
L3 |
| The category of perverse sheaves, Perv_X, on a stratified space X plays an important role in the Intersection cohomology of Goresky-MacPherson and on the theory of D-modules. It is defined as a subcategory of the derived category of sheaves. Hence a usual complaint is that there are not very concrete objects. A lot of work has been done to describe Perv_X more explicitly. Hence many methods had been develop to describe Perv_X as a category of quiver representations. An important property of perverse sheaves is that they can be viewed as a stack, it means that a perverse sheaf can be defined up to isomorphism from the data of perverse sheaves on an open cover of X plus some glueing data. In this talk we show how the theory of stacks and more precisely the notion of constructible stacks can be used in order to glue a description due to Galligo, Granger and Maisonobe of the category Perv_X when X is C^n stratified by a normal crossing stratification. Thanks to this we will obtain a description of Perv_X on smooth toric varieties stratified by the torus action. | |||
