| 25. August |
Olav Arnfinn Laudal (Oslo)
Non-commutative deformation theory, algebraic geometry, quantum fields and quarks, I
|
| 1. September |
Olav Arnfinn Laudal (Oslo)
Non-commutative deformation theory, algebraic geometry, quantum fields and quarks, II
|
| 8. September |
Olav Arnfinn Laudal (Oslo)
Non-commutative deformation theory, algebraic geometry, quantum fields and quarks, III
|
| 15. September |
Ragni Piene (Oslo)
Classifying smooth lattice polytopes via toric fibrations I
Abstract:
Let P be a convex n-dimensional lattice polytope in R^n. Its
codegree is the smallest integer m such that mP has interior lattice
points. Cayley polytopes are examples of polytopes with large codegree.
In a joint work with A. Dickenstein and S. Di Rocco we partially answer
a question of Batyrev and Nill, by showing that all smooth Q-normal
polytopes with codegree at least (n+3)/2 are strict Cayley polytopes.
Our proof relies on the study of the nef value and the nef value map of
a nonsingular polarized toric variety (X,L).
|
| 22. September |
Ragni Piene (Oslo)
Classifying smooth lattice polytopes via toric fibrations II
|
| 29. September |
Algebra lunch
|
| 6. October |
Algebra lunch
|
| 13. October |
David Rydh (KTH, Stockholm)
Families of cycles
Abstract:
The Chow variety, parameterizing cycles on a projective space, was
introduced by Chow and van der Waerden in 1937 but its functorial aspects
are still not well understood. In this talk I will define, in any
characteristic, a functor parameterizing cycles which is closely related
to the Chow variety. It (conjecturally in some cases) generalizes the
functorial descriptions of Barlet, Ang\'eniol, Guerra, Koll\'ar and
Suslin-Voevodsky. It also explains related work by Mumford and Fogarty.
|
| 20. October |
Edoardo Sernesi (Roma)
The curve of lines on a Fano 3-fold of genus 8
Abstract:
I will report on joint work with F. Flamini in which we
prove a variant of Torelli's theorem for Fano 3-folds of genus 8
based on the geometry of the curve of lines on the 3-fold.
|
| 27. October |
Kristian Ranestad (Oslo)
Toric polar Cremona transformations
|
| 30.-31. October |
Nasjonalt algebramøte
|
| 3. November |
Algebra lunch
|
| 10. November | David Eklund (KTH,
Stockholm)
Algebraic C*-actions and homotopy
continuation
Abstract:
Let X be a smooth projective
variety over C equipped with a C*-action whose fixed points are
isolated. Let Y and Z be subvarieties of X of complementary dimensions
in X. I will present a method for approximating the isolated points of
intersection between Y and Z based on homotopy continuation and the
Bialynicki-Birula decompositions of X into locally closed invariant
subsets. The method was developed with applications to mechanics in
mind and I will explain how it gives a new solution to the inverse
kinematic problem of a so-called six-revolute serial-link mechanism.
|
| 17. November | Arne B. Sletsjøe (Oslo)
Deformasjoner under bibetingelser
| <7tr>
| 24. November |
Algebra lunch
|
| 1. December |
Algebra lunch
|
| 8.-9. December, B63 |
Lutefisk-seminars in B63 (both days):
Monday 8.:
11.45: Algebra lunch (6.etg NHA)
12.15: Dan Laksov (KTH)
Splitting algebraer
Sammendrag:
Vi gir definisjoner, konstruksjoner, og egenskaper
til splitting algebraer.
13.15: Stephanie Yang (KTH)
Faber-type conjectures on moduli spaces of curves
Abstract:
In this talk I will review Faber's conjectures and known
results concerning tautological rings of moduli spaces of curves, and
describe recent attempts to extend these to other moduli spaces.
19.30: Dinner, Rorbua (Aker Brygge) Lutefisk/juletallerken
Tuesday 9.:
10.15: Sandra Di Rocco (KTH)
Some results on reducible hyperplane sections
Abstract:
A cone with vertex a point in projective space has the
property that every hyperplane section
through the vertex is reducible.
How restrictive is to ask that given an (ample and spanned) linear
system |L| on
a variety X, there is at least a point, x, such that all elements
passing through x are reducible or non reduced?
The possibilities are indeed very limited, X is a surface and it is
mapped by |L| to a cone. This is work of Bertni, Besana-Di Rocco-Lanteri
and Lanteri-De Fernex.
I will report on some recent work, with Besana-Lanteri, concerning
linear systems whose elements passing through higher degree zero-schemes
are reducible.
In particular how big can the locus of such "bad zero-schemes" be in the
appropriate Hilbert scheme?
11.15:Roy Skjelnes (KTH)
Parameterizing distinct points in a variety.
Abstract:
Let H denote the Hilbert scheme parameterizing n points on a
separated algebraic space X over an arbitrary base space. Using sheaf
theoretical methods it is easy to construct the open subspace U of H
parameterizing distinct points. However, by studying the space U locally
one obtains, surprisingly enough, information about how distinct points
degenerates. This information can be used to construct the schematic
closure of U in H, which in fact was done recently in a joint work with
David Rydh. |
