- International Electronic Journal of Algebra
- Volume:24 Issue:24
- A NOTE ON THE DEPTH OF A SOURCE ALGEBRA OVER ITS DEFECT GROUP
A NOTE ON THE DEPTH OF A SOURCE ALGEBRA OVER ITS DEFECT GROUP
Authors : Markus LİNCKELMANN
Pages : 68-72
Doi:10.24330/ieja.440216
View : 11 | Download : 9
Publication Date : 2018-07-05
Article Type : Research Paper
Abstract :By results of Boltje and Kulshammer, if a source algebra A of a principal p-block of a nite group with a defect group P with inertial quotient E is a depth two extension of the group algebra of P, then A is isomorphic to a twisted group algebra of the group P o E. We show in this note that this is true for arbitrary blocks. We observe further that the results of Boltje and Kulshammer imply that A is a depth two extension of its hyperfocal subalgebra, with a criterion for when this is a depth one extension. By a result of Watanabe, this criterion is satised if the defect groups are abelian.Keywords : Source algebra