Virtually nilpotent groups with finitely many orbits under automorphisms

Autor: Alex C. Dantas, Emerson de Melo, Raimundo Bastos
Rok vydání: 2020
Předmět:
DOI: 10.48550/arxiv.2008.10800
Popis: Let G be a group. The orbits of the natural action of $${{\,\mathrm{Aut}\,}}(G)$$ on G are called automorphism orbits of G, and the number of automorphism orbits of G is denoted by $$\omega (G)$$ . Let G be a virtually nilpotent group such that $$\omega (G)< \infty $$ . We prove that $$G = K \rtimes H$$ where H is a torsion subgroup and K is a torsion-free nilpotent radicable characteristic subgroup of G. Moreover, we prove that $$G^{'}= D \times {{\,\mathrm{Tor}\,}}(G^{'})$$ where D is a torsion-free nilpotent radicable characteristic subgroup. In particular, if the maximum normal torsion subgroup $$\tau (G)$$ of G is trivial, then $$G^{'}$$ is nilpotent.
Databáze: OpenAIRE