Oberseminar Algebraische Komplexitätstheorie

Wintersemester 2011/2012

Prof. Dr. Peter Bürgisser



Vorträge

Do, 10.11.2011 16:00 A3.301 A study of the representations supported by the orbit closure of the determinant
und Christian Ikenmeyer
Do, 17.11.2011 16:00 A3.301

Der Vortrag befasst sich mit einer erst kürzlich erschienenen Arbeit von Shrawan Kumar, [ arXiv:1109.5996v1 ]. Es geht um die explizite Konstruktion irreduzibler Darstellungen im Koordinatenring des Orbitabschlusses der Determinante, einem zentralen Objekt in der Geometrischen Komplexitätstheorie.

 
Do, 24.11.2011 16:00 A3.301 On Polynomials Defined by Acyclic Conjunctive Queries and Weighted Counting Problems
und Stefan Mengel
Do, 01.12.2011 16:00 A3.301

TBA

und
Do, 08.12.2011 16:00 A3.301
und
Di, 13.12.2011 16:00 C3.232
 
Do, 22.12.2011 16:00 A3.301 Spherical intrinsic volumes and combinatorics
Dennis Amelunxen

In this talk we will describe some new ideas how spherical intrinsic volumes may be approached in a combinatorial way. As a first successful example of this approach we will compute the intrinsic volumes of the cones {x_1 >=...>= x_n} and {x_1 >=...>= x_n >= 0}. As a side result, we will obtain a new characterization of the Stirling numbers of the first kind.

 
Do, 02.02.2012 16:00 A3.301 Compressed sensing and spherical intrinsic volumes
Dennis Amelunxen

Compressed sensing deals with the task of finding sparse solutions, i.e., solutions with lots of zero entries, to underdetermined systems of linear equations. We will give an introduction to this theory with a special emphasis on the geometric interpretation. In particular, we will show how the theory of spherical intrinsic volumes naturally fits in this area of research.

 
Mi, 15.02.2012 14:00 A3.301 Sylvester-Gallai-Konfigurationen und verzweigte Überlagerungen
Jesko Hüttenhain

Abstract