BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The Ext algebra of a Brauer graph algebra - Nicole Snashall\, Leic
 ester
DTSTART:20131204T163000Z
DTEND:20131204T173000Z
UID:TALK48655@talks.cam.ac.uk
CONTACT:David Stewart
DESCRIPTION:Brauer graph algebras are generalizations of Brauer tree algeb
 ras\, which\nwere used\, for group algebras KG over a finite group G\, to 
 study blocks\nwith cyclic defect groups. Brauer graph algebras have since 
 played a major\nrole in the classification of finite-dimensional self-inje
 ctive algebras\nof tame representation type.\n\nOne of the fundamental que
 stions is when is the Ext algebra of a given\nalgebra itself finitely gene
 rated? This talk will describe the Ext algebra\nof a Brauer graph algebra\
 , as well as discussing various generalizations\nof the Koszul property fo
 r Brauer graph algebras. We note that it is\nwell-known that the Ext algeb
 ra of a Koszul algebra is generated in\ndegrees 0 and 1\, so is finitely g
 enerated. This is joint work with Green\,\nSchroll and Taillefer.\n\nIn or
 der to describe the Ext algebra\, we use a theory of coverings of\nBrauer 
 graphs which are compatible with coverings of Brauer graph\nalgebras\; thi
 s is joint work with Green and Schroll. In particular\, we\nclassify the c
 overings of Brauer graph algebras that are again Brauer\ngraph algebras\, 
 and show that there is a tower of coverings so that any\nBrauer graph can 
 be covered by a Brauer graph that has multiplicity\nfunction precisely 1\,
  no loops and no multiple edges.
LOCATION:MR12
END:VEVENT
END:VCALENDAR