Séminaires : Séminaire sur les Algèbres Enveloppantes

Equipe(s) :
Responsables :J.-Y. Charbonnel, R. Rentschler, M. Varagnolo
Email des responsables : Jean-Yves Charbonnel <jyc@math.jussieu.fr>, Rudolf Rentschler <rent@math.jussieu.fr>, Michela Varagnolo <varagnol@math.u-cergy.fr>
Salle : 175 rue du Chevaleret - 75013 Paris
Adresse :
Description

Orateur(s) David STEWART - Oxford University,
Titre Bounding cohomology .
Date01/03/2013
Horaire11:00 à 12:00
Diffusion
RésumeA lot of recent research has sprung out of work towards a conjecture of Guralnick: There is a constant $c$ such that for any finite group $G$ and irreducible, faithful representation $V$ for $G$, the dimension of $H^1(G,V)$ is less than $c$. This conjecture reduces to the case of simple groups. New computer calculations of F. Luebeck and a student of L. Scott show that it is likely that the conjecture is wrong, but if one fixes either the dimension of $V$ or the Lie rank of $G$ then there do exist bounds, due to Parshall--Scott (defining characteristic) and Guralnick--Tiep (cross characteristic). The latter is explicit and the former has now been made explicit by some recent work of A. Parker and myself. There are many more general results, however. I'll give an overview of the area.
Salle175 rue du Chevaleret - 75013 Paris
Adresse
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