Decomposition numbers of SU(3,q2)

PARITIES OF v-DECOMPOSITION NUMBERS

We prove that the v-decomposition number dλμ(v) arising from the canonical basis of the Fock space representation of Uv(ŝle) is an even or odd polynomial according to whether the partitions λ and μ have the same relative e-sign (or e-parity) or not.

Decomposition numbers for symmetric groups

Where to find decomposition matrices? Try www.math.rwth-aachen.de/∼MOC In hard copy, [6] has several (at the end) for small primes. For p = 2, a paper by Juergen Mueller(Aachen) [7], for an electronic version try his homepage. General background can be found in [6]. Column removal: Due to G.D. James, sometime after '76. Just now I cannot find the precise reference. However, a generalization of ...

Cover-Decomposition and Polychromatic Numbers

A colouring of a hypergraph’s vertices is polychromatic if every hyperedge contains at least one vertex of each colour; the polychromatic number is the maximum number of colours in such a colouring. Its dual, the cover-decomposition number, is the maximum number of disjoint hyperedgecovers. In geometric hypergraphs, there is extensive work on lower-bounding these numbers in terms of their trivi...

Path and cycle decomposition numbers

Decomposition Numbers for Perverse Sheaves

The purpose of this article is to set foundations for decomposition numbers of perverse sheaves, to give some methods to calculate them in simple cases, and to compute them concretely in two situations: for a simple (Kleinian) surface singularity, and for the closure of the minimal non-trivial orbit in a simple Lie algebra. This work has applications to modular representation theory, for Weyl g...