arXiv subjects

S. J. van Willigenburg

Publications and source records attributed to S. J. van Willigenburg.

3 recordsLinked to original sources

arXiv2007

The $p$-modular descent algebras

The concept of descent algebras over a field of characteristic zero is extended to define descent algebras over a field of prime characteristic. Some basic algebraic structure of the latter, including its radical and irreducible modules, is then determined. The decomposition matrix of the descent algebras of Coxeter group types $A$, $B$, and $D$ are calculated, and used to derive a description of the decomposition matrix of an arbitrary descent algebra. The Cartan matrix of a variety of descent algebras over a finite field is then obtained.

math.CO↗

arXiv2007

The p-modular Descent Algebra of the Symmetric Group

The descent algebra of the symmetric group, over a field of non-zero characteristic p, is studied. A homomorphism into the algebra of generalised p-modular characters of the symmetric group is defined. This is then used to determine the radical, and its nilpotency index. It also allows the irreducible representations of the descent algebra to be described.

math.CO↗

arXiv2007

On the Descent Algebra of Type $D$

Here we give a combinatorial interpretation of Solomon's rule for multiplication in the descent algebra of Weyl groups of type $D$, $ΣD_n$. From here we show that $ΣD_n$ is a homomorphic image of the descent algebra of the hyperoctahedral group, $ΣB_{n-2}$.

math.CO↗