T-group (mathematics)

Source: Wikipedia, the free encyclopedia.

In mathematics, in the field of group theory, a T-group is a group in which the property of normality is transitive, that is, every subnormal subgroup is normal. Here are some facts about T-groups:

  • Every simple group is a T-group.
  • Every quasisimple group is a T-group.
  • Every abelian group is a T-group.
  • Every
    Hamiltonian group
    is a T-group.
  • Every nilpotent T-group is either abelian or Hamiltonian, because in a nilpotent group, every subgroup is subnormal.
  • Every normal subgroup of a T-group is a T-group.
  • Every homomorphic image of a T-group is a T-group.
  • Every solvable T-group is metabelian.

The solvable T-groups were characterized by

acted upon by conjugation as a group of power automorphisms
by G.

A

PT-group
is a group in which permutability is transitive. A finite T-group is a PT-group.

References