Semigraphoids, permutohedra, and mice

Monday, September 25, 2006 - 9:30am - 10:30am
Lind 305
Bernd Sturmfels (University of California, Berkeley)
Semigraphoids are combinatorial structures that arise in statistical learning theory. They are equivalent to convex rank tests and to polyhedral fans that coarsen the reflection arrangement of the symmetric group. This lecture gives an introduction to this theory. It centers around our recent answers to questions raised by Matus, Studeny, Postnikov, Reiner and Williams. This represents joint work with R.Hemmecke, J.Morton, L.Pachter, A.Shiu and O. Wienand. The mice are in the title because everything started with the analysis of microarray data in molecular biology.

Reading: Milan Studeny: Probabilistic Conditional Independence Structures, Springer Series in Information Science and Statistics, 2005.