English

Rook placements and Jordan forms of upper-triangular nilpotent matrices

Combinatorics 2017-03-02 v1

Abstract

The set of n by n upper-triangular nilpotent matrices with entries in a finite field F_q has Jordan canonical forms indexed by partitions lambda of n. We present a combinatorial formula for computing the number F_\lambda(q) of matrices of Jordan type lambda as a weighted sum over standard Young tableaux. We also study a connection between these matrices and non-attacking rook placements, which leads to a refinement of the formula for F_\lambda(q).

Keywords

Cite

@article{arxiv.1703.00057,
  title  = {Rook placements and Jordan forms of upper-triangular nilpotent matrices},
  author = {Martha Yip},
  journal= {arXiv preprint arXiv:1703.00057},
  year   = {2017}
}

Comments

25 pages, 6 figures

R2 v1 2026-06-22T18:31:28.456Z