Mathematics – Group Theory
Scientific paper
2007-07-24
Mathematics
Group Theory
16 pages, changed contents and title
Scientific paper
Let $G$ be a finite group and $N$ be a normal subgroup of $G$. Let $J=J(F[N])$ denote the Jacboson radical of $F[N]$ and $I={\rm Ann}(J)=\{\alpha \in F[G]|J\alpha =0\}$. We have another algebra $F[G]/I$. We study the decomposition of Cartan matrix of $F[G]$ according to $F[G/N]$ and $F[G]/I$. This decomposition establishs some connections between Cartan invariants and chief composition factors of $G$. We find that existing zero-defect $p$-block in $N$ depends on the properties of $I$ in $F[G]$ or Cartan invariants. When we consider the Cartan invariants for a block algebra $B$ of $G$, the decomposition is related to what kind of blocks in $N$ covered by $B$. We mainly consider a block $B$ of $G$ which covers a block $b$ of $N$ with $l(b)=1$. In two cases, we prove Willems' conjecture holds for these blocks, which covers some true cases by Holm and Willems. Furthermore We give an affirmative answer to a question by Holm and Willems in our cases. Some other results about Cartan invariants are presented in our paper.
No associations
LandOfFree
Decomposition of Cartan Matrix and conjectures on Brauer character degrees does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Decomposition of Cartan Matrix and conjectures on Brauer character degrees, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Decomposition of Cartan Matrix and conjectures on Brauer character degrees will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-440068