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Finite general linear groups

Applications for representation theory of GLn(Fq)\mathrm{GL}_n(\mathbb{F}_q)

Green polynomials

The app Green polynomials allows one to compute Green polynomials for GLn(Fq)\mathrm{GL}_n\left( \mathbb{F}_q \right). It uses Theorem 2.6 from the article The Green polynomials via vertex operators by Naihuan Jing and Ning Liu.

Characters tables of GLn(Fq)\mathrm{GL}_n(\mathbb{F}_q)

The following set of pages allows one to explore the character tables of GLn(Fq)\mathrm{GL}_n(\mathbb{F}_q). It implements the formula established by Green in The characters of the finite general linear groups.

  • Representation list - allows one to inspect all the different types of representations of GLn(Fq)\mathrm{GL}_n(\mathbb{F}_q) for a given nn. Try n=2n = 2 to see the classical classification of irreducible representations of GL2(Fq)\mathrm{GL}_2(\mathbb{F}_q)!
  • Conjugacy class list - allows one to inspect all the different types of conjugacy classes of GLn(Fq)\mathrm{GL}_n(\mathbb{F}_q) for a given nn. Try n=2n = 2 to see the classical classification of conjugacy classes of GL2(Fq)\mathrm{GL}_2(\mathbb{F}_q)!

These two pages link to the following pages.

  • Character formula - allows one to view Green's character formula for a given representation. For example, the input (1, [1], \alpha), (1, [1], \beta) corresponds to an irreducible generic principal series representation of GL2(Fq)\mathrm{GL}_2(\mathbb{F}_q), while the input (4, [1], \theta) corresponds to an irreducible cuspidal representation of GL4(Fq)\mathrm{GL}_4(\mathbb{F}_q).
  • Conjugacy class formula - allows one to view Green's character formula for a given conjugacy class. For example, the input (1, [1], x), (1, [1], y) corresponds to a diagonal matrix in GL2(Fq)\mathrm{GL}_2(\mathbb{F}_q), while the input (4, [1], \xi) corresponds to a regular elliptic element in GL4(Fq)\mathrm{GL}_4(\mathbb{F}_q).

Generealized Gelfand-Graev multiplicities

The Character formula page links to Gelfand-Graev multiplicities. This pages displays the multiplicities of a given representation in every possible generalized Gelfand--Graev representation. It is based on Sections 3.1.1-3.1.2 and Proposition 5.7 of the paper The combinatorics of GLn\mathrm{GL}_n generalized Gelfand–Graev characters by Scott Andrews and Nathaniel Thiem. See for example the multiplicities of the following two Speh representations for GL6(Fq)\mathrm{GL}_6(\mathbb{F}_q): Δ(τ3,2)\Delta(\tau_3, 2), Δ(τ2,3)\Delta(\tau_2, 3).