Universität Jena, Fakultät für Mathematik & Informatik, Lehrstuhl Algebra

Oberseminar Algebra/Zahlentheorie - Vorträge 2012


WS 2012/13

Dienstag, den 18. Dezember 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Prof. Robert Boltje   (University of California, Santa Cruz, USA)
"Invariants of p-permutation equivalences"
Dienstag, den 27. November 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Dmitri Panyushev   (Moskau)
"Invariants of abelian groups and the permanent of the Cayley table"
Dienstag, den 20. November 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Lászlo Héthelyi   (Budapest)
"The combinatorial depth of subgroups of Suzuki groups"
Dienstag, den 13. November 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Simon King   (Universität Jena)
"An F5-algorithm for basic algebras and the computation of Loewy layers"
Dienstag, den 6. November 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Gemeinsames Oberseminar mit dem Mathematischen Institut der Universität Halle-Wittenberg
14:15-15:15 Uhr Jun.-Prof. Dr. Rebecca Waldecker   (Universität Halle-Wittenberg)
"Permutationsgruppen, in denen nicht-triviale Elemente wenige Fixpunkte haben "
15:45-16:45 Uhr Prof. Charles Leedham-Green   (University of London)
"Classifying p-groups by coclass"
17:00-18:00 Uhr Jun.-Prof. Dr. Susanne Danz   (Universität Kaiserslautern)
"Ghost-Algebren für doppelte Burnside-Algebren"
Dienstag, den 30. Oktober 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Burkhard Kuelshammer   (Universität Jena)
"Zur Loewy-Laenge von Bloecken"
Dienstag, den 23. Oktober 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
René Reichenbach   (Universität Jena)
"Fusionssysteme auf 2-Gruppen mit 3 Involutionen"
Dienstag, den 16. Oktober 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Manuel Maier   (Universität Jena)
"Mengentheoretische Loesungen der Yang-Baxter-Gleichung"

SS 2012

Dienstag, den 10. Juli 2012, in HALLE/Saale, SR 3, Georg-Cantor-Haus, Theodor-Lieser-Str. 5
Gemeinsames Oberseminar mit dem Mathematischen Institut der Universität Halle-Wittenberg
14:15-15:15 Uhr O. Yakimova   (Universität Jena)
"Koadjungierte Darstellung (bi) parabolischer Lie-Algebren"
15:45-16:45 Uhr E. Henke   (University Kopenhagen)
"Fusion und Kohomologie"
17:00-18:00 Uhr M. Grimm   (Universität Halle-Wittenberg)
"Große Untergruppen von Gruppen gerader Ordnung"
Dienstag, den 12. Juni 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Dr. Konrad Schöbel   (Universität Jena)
"Integrable Killing-Tensoren auf der 3-Sphäre"
Dienstag, den 22. Mai 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Prof. Radha Kessar   (University of Aberdeen)
"Quasi-isolated blocks and Brauer's height zero conjecture"
Dienstag, den 15. Mai 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Carolin Reiche   (Universität Jena)
"Die Tiefe von Young-Untergruppen symmetrischer Gruppen"
Dienstag, den 8. Mai 2012, SR 3517 Ernst-Abbe-Platz 2
Gemeinsames Oberseminar mit dem Mathematischen Institut der Universität Halle-Wittenberg
14:15-15:15 Uhr Prof. Dr. G. Stroth   (Universität Halle-Wittenberg)
"Small modules"
15:45-16:45 Uhr Prof. Dr. K. Magaard   (University Birmingham)
"Representations of finite unipotent groups"
17:00-18:00 Uhr Prof. D. Green   (Universität Jena)
"On Oliver's p-group conjecture"
Dienstag, den 24. April 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Dozent Dmitry Timashev   (Moscow State University)
"Hamiltonian symplectic varieties with invariant Lagrangian subvarieties (joint work with V.S.Zhgoon)"
Abstract: Recall that a smooth manifold (or algebraic variety) M is symplectic, if there is a closed differential 2-form on M, which induces a symplectic form on each tangent space T_pM, where p is a point of M. A submanifold (subvariety) S is Lagrangian, if dim S = (dim M)/2 and for each p in S the symplectic form on T_pM vanishes on T_pS. Similar to the Riemannian situation, one can speak about the group of symplectic automorphisms of M. An action of a Lie (or an algebraic) group G on M is Hamiltonian, if the elements of G act by symplectic automorphisms and some other natural condition (the existence of a moment map), which will be explained in the talk, is satisfied. We are interested in G-invariant Lagrangian subvarieties of M. A typical example is provided by the cotangent bundle M=T^*X of a G-variety X, where X itself, identified with the zero section of T^*X, is an invariant Lagrangian subvariety.
It is well known in symplectic geometry that a symplectic manifold in a neighbourhood of a Lagrangian submanifold is locally isomorphic to the cotangent bundle of this submanifold. This result holds even in the equivariant setting for Hamiltonian actions of compact Lie groups. If we pass from differential geometry to algebraic (or complex-analytic) geometry and replace compact Lie groups with reductive algebraic groups, as a natural counterpart, then the situation becomes more delicate. However, we prove that several important invariants of a Hamiltonian action, such as corank, defect, and the image of the moment map, coincide for a given Hamiltonian variety M and for the cotangent bundle of any invariant Lagrangian subvariety S. The proof is based on deformation of M to the normal bundle of S and on the so-called "local structure theorem", which describes the action of a certain parabolic subgroup on an open subset of the given variety. Some of our results extend to invariant coisotropic subvarieties. There is some hope to obtain important applications in representation theory.
Dienstag, den 17. April 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Dr. Qiong Guo   (Universität Stuttgart)
"On the U−module Structure of Unipotent Specht Modules of Finite General Linear Groups"

WS 2011/12

Donnerstag, den 2.Februar 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Prof. Gerald Schwarz   (University Brandeis)
"Quotients of finite and compact groups acting on Euclidean space"
Abstract: pdf-Datei
Dienstag, den 31. Januar 2012, 14:15 Uhr, SR 3517 Ernst-Abbe-Platz 2
Prof. Gregor Kemper   (TU München)
"Invariantentheorie und die Cohen-Macaulay-Eigenschaft"


Autor: <Ines.Spilling (at) uni-jena.de>.
Zuletzt geändert am 19.08.13