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Related papers: A note on compact-like semitopological groups

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This paper investigates the interplay between algebraic structure, topology, and differentiability in Clifford semigroups. The study is developed along three main themes. First, in the compact Hausdorff setting, we provide an explicit…

General Topology · Mathematics 2026-04-28 Stefano Bonzio , Andrea Loi , Giuseppe Zecchini

We reveal new aspects of the structure of Hilbert space $C_0$-semigroups $\mathcal T = (T(t))_{t\ge 0}$ similar to semigroups of contractions. In particular, we prove that $\mathcal T$ is similar to a semigroup of contractions if and only…

Functional Analysis · Mathematics 2025-09-04 J. Oliva-Maza , Y. Tomilov

This paper provides a complete characterization of quasicontractive groups and analytic $C_0$-semigroups on Hardy and Dirichlet space on the unit disc with a prescribed generator of the form $Af=Gf'$. In the analytic case we also give a…

Functional Analysis · Mathematics 2016-01-13 C. Avicou , I. Chalendar , J. R. Partington

In this paper we consider a semitopological $\alpha$-bicyclic monoid $\mathcal{B}_{\alpha}$ and prove that it is algebraically isomorphic to a semigroup of all order isomorphisms between the principal upper sets of the ordinal…

General Topology · Mathematics 2020-08-09 Serhii Bardyla

We show that the Heisenberg type group $H_X=(\Bbb{Z}_2 \oplus V) \leftthreetimes V^{\ast}$, with the discrete Boolean group $V:=C(X,\Z_2)$, canonically defined by any Stone space $X$, is always minimal. That is, $H_X$ does not admit any…

General Topology · Mathematics 2011-06-08 Michael Megrelishvili , Menachem Shlossberg

There are strong analogies between groups definable in o-minimal structures and real Lie groups. Nevertheless, unlike the real case, not every definable group has maximal definably compact subgroups. We study definable groups G which are…

Logic · Mathematics 2009-12-25 Annalisa Conversano

For a connected Lie group $G$ and an automorphism $T$ of $G$, we consider the action of $T$ on Sub$_G$, the compact space of closed subgroups of $G$ endowed with the Chabauty topology. We study the action of $T$ on Sub$^p_G$, the closure in…

Dynamical Systems · Mathematics 2025-09-10 Debamita Chatterjee , Riddhi Shah

Suppose $\mathcal{G}$ is a second-countable locally compact Hausdorff \'{e}tale groupoid, $G$ is a discrete group containing a unital subsemigroup $P$, and $c:\mathcal{G}\rightarrow G$ is a continuous cocycle. We derive conditions on the…

Operator Algebras · Mathematics 2019-06-10 Lisa Orloff Clark , James Fletcher

We say that an element $g$ of a group $G$ is almost right Engel if there is a finite set ${\mathscr R}(g)$ such that for every $x\in G$ all sufficiently long commutators $[...[[g,x],x],\dots ,x]$ belong to ${\mathscr R}(g)$, that is, for…

Group Theory · Mathematics 2018-07-18 E. I. Khukhro , P. Shumyatsky

Let $\sigma =\{\sigma_{i} | i\in I\}$ be some partition of the set of all primes $\Bbb{P}$, $G$ a finite group and $\sigma (G) =\{\sigma_{i} |\sigma_{i}\cap \pi (G)\ne \emptyset \}$. A set ${\cal H}$ of subgroups of $G$ is said to be a…

Group Theory · Mathematics 2016-09-29 Wenbin Guo , Alexander N. Skiba

A Polish group $G$ is called a group of quasi-invariance or a QI-group, if there exist a locally compact group $X$ and a probability measure $\mu$ on $X$ such that 1) there exists a continuous monomorphism of $G$ to $X$, and 2) for each…

General Topology · Mathematics 2009-10-01 S. S. Gabriyelyan

A group $G$ is called automatically continuous if any homomorphism from a completely metrizable or locally compact Hausdorff group to $G$ has open kernel. In this paper, we study preservation of automatic continuity under group-theoretic…

Group Theory · Mathematics 2020-10-07 Samuel M. Corson , Ilya Kazachkov

We prove that if $G$ is a group of automorphisms of a regular locally finite building which is closed in the compact-open topology and acts Weyl transitively on the building, then $G$ admits just one Hausdorff locally compact…

Group Theory · Mathematics 2014-11-06 Rupert McCallum

We describe the autotopism group Atp(G) of any abelian group G as being a semidirect product of its automorphism group Aut(G) and G^2. We then provide the subgroup structure of Atp(G) when G is a finite cyclic group.

Group Theory · Mathematics 2012-01-30 Lucien Clavier

We study the topology of compact manifolds with a Lie group action for which there are only finitely many non-principal orbits, and describe the possible orbit spaces which can occur. If some non-principal orbit is singular, we show that…

Differential Geometry · Mathematics 2011-06-20 Stefan Bechtluft-Sachs , David J. Wraith

We study conditions under which the germinal groupoid associated to a minimal equicontinuous action of a countable group on a Cantor set has non-Hausdorff topology. We develop a new criterion, which serves as an obstruction for the \'etale…

Dynamical Systems · Mathematics 2024-06-14 Olga Lukina

In this paper we study continuous semigroups of positive operators on general vector lattices equipped with the relative uniform topology $\tau_{ru}$. We introduce the notions of strong continuity with respect to $\tau_{ru}$ and relative…

Functional Analysis · Mathematics 2018-12-18 Marko Kandić , Michael Kaplin

If a fintie group G acts topologically and faithfully on R^3, then G is a subgroup of O(3)

Algebraic Topology · Mathematics 2016-03-11 Fang Sun

In this paper, it is shown that every right $\omega$-narrow strongly topological gyrogroup $G$ is right $\omega$-balanced by applying the gyrosemidirect product groups. Then we investigate the class of $\sigma$-compact strongly topological…

General Topology · Mathematics 2026-05-25 Shumin Lai , Fucai Lin

In the present paper, the structure of a finite group $G$ having a nonnormal T.I. subgroup $H$ which is also a Hall $\pi$-subgroup is studied. As a generalization of a result due to Gow, we prove that $H$ is a Frobenius complement whenever…

Group Theory · Mathematics 2018-06-05 M. Yasir Kızmaz