Invariants of finite groups

on some invariants of finite groups

in this note we are going to survey several invariants of finite groups related either to their orders or to generating sets or to lattices of subgroups. some relations among these invariants will be exhibited. special attention will be paid to monotonicity of them.

Constructing Invariants for Finite Groups

Rings of Invariants of Finite Groups

We shall prove the fundamental results of Hilbert and Noether for invariant subrings of finite subgroups of the general linear groups in the non-modular case, i.e. when the field has characteristic zero or coprime with the order of the group. We will also derive the Molien’s formula for the Hilbert series of the ring of invariants. We will show, through examples, that the Molien’s formula helps...

Computation of invariants of finite abelian groups

We investigate the computation and applications of rational invariants of the linear action of a finite abelian group in the non-modular case. By diagonalization, such a group action can be described by integer matrices of orders and exponents. We make use of integer linear algebra to compute a minimal generating set of invariants along with the substitution needed to rewrite any invariant in t...

Computing the Invariants of Finite Abelian Groups

We investigate the computation and applications of rational invariants of the linear action of a finite abelian group in the non-modular case. By diagonalization, the group action is accurately described by an integer matrix of exponents. We make use of linear algebra to compute a minimal generating set of invariants and the substitution to rewrite any invariant in terms of this generating set....