English

On the semigroup $\textbf{ID}_{\infty}$

Group Theory 2019-04-16 v1

Abstract

We study the semigroup ID\textbf{{ID}}_{\infty} of all partial isometries of the set of integers Z\mathbb{Z}. It is proved that the quotient semigroup ID/Cmg\textbf{{ID}}_{\infty}/\mathfrak{C}_{\textsf{mg}}, where Cmg\mathfrak{C}_{\textsf{mg}} is the minimum group congruence, is isomorphic to the group Iso(Z){\textsf{Iso}}(\mathbb{Z}) of all isometries of Z\mathbb{Z}, ID\textbf{{ID}}_{\infty} is an FF-inverse semigroup, and ID\textbf{{ID}}_{\infty} is isomorphic to the semidirect product Iso(Z)hP ⁣(Z){\textsf{Iso}}(\mathbb{Z})\ltimes_\mathfrak{h}\mathscr{P}_{\!\infty}(\mathbb{Z}) of the free semilattice with unit (P ⁣(Z),)(\mathscr{P}_{\!\infty}(\mathbb{Z}),\cup) by the group Iso(Z){\textsf{Iso}}(\mathbb{Z}). We give the sufficient conditions on a shift-continuous topology τ\tau on ID\textbf{{ID}}_{\infty} when τ\tau is discrete. A non-discrete Hausdorff semigroup topology on ID\textbf{{ID}}_{\infty} is constructed. Also, the problem of an embedding of the discrete semigroup ID\textbf{{ID}}_{\infty} into Hausdorff compact-like topological semigroups is studied.

Keywords

Cite

@article{arxiv.1904.06644,
  title  = {On the semigroup $\textbf{ID}_{\infty}$},
  author = {Oleg Gutik and Anatolii Savchuk},
  journal= {arXiv preprint arXiv:1904.06644},
  year   = {2019}
}

Comments

12 pages, in Ukrainian

R2 v1 2026-06-23T08:38:53.305Z