3
$\begingroup$

Suppose that $G$ is a regular feebly compact Moore quasitopological group. Must $G$ be a topological group? This was previously posted here on MathSE also.

A semitopological group $G$ is a group $G$ with a topology such that the product map of $G\times G$ into $G$ is separately continuous. If G is a semitopological group and the inverse map of $G$ onto itself associating $x^{-1}$ with arbitrary $x\in G$ is continuous, then $G$ is called a quasitopological group. If $G$ is a quasitopological group and the product map of $G\times G$ into $G$ is jointly continuous, then $G$ is called a topological group.

A space is feebly compact if every family of locally finite non-empty open sets is finite.

Note that if $G$ is Tychonoff, the answer to this question is true,since $G$ will be Cech complete.

$\endgroup$

1 Answer 1

3
$\begingroup$

Yes. The paper [KKM] contains more general results. In particular, by Corollary 1 each regular semitopological group which is a cover semi-complete Baire space is a topological group. It remains to note that each $p-\sigma$-fragmentable space (see [Bou] for the definition) (in particlar, each $p$-space, so each Moore space) is cover semi-complete [KKM] and a (quasi)regular feebly compact space is Baire.

References

[Bou] Ahmed Bouziad, Every Cech-analytic Baire semi-topological group is a topological group, Proc. Amer. Math. Soc. 124 (1996), 953-959.

[KKM] P. S. Kenderov, I. S. Kortezov, W. B. Moors Topological games and topological groups, Topology Appl. 109 (2001) P.157-165. (I have a preprint, to which I referred).

$\endgroup$
1
  • 1
    $\begingroup$ It is very useful for me, thank you!! $\endgroup$
    – Paul
    Jun 15, 2018 at 7:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.