Existence of abelian group which has no “square-root” but whose “cube” has a “square-root”












4












$begingroup$


Does there exist an abelian group $G$ such that $G ncong H times H$ for every abelian group $H$ but $G times G times G cong K times K$ for some abelian group $K$ ?



Also see Existence of topological space which has no "square-root" but whose "cube" has a "square-root"










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$endgroup$








  • 1




    $begingroup$
    Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
    $endgroup$
    – Crostul
    Dec 27 '18 at 1:15






  • 4




    $begingroup$
    @RobArthan: no ... I do mean what I wrote ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:38






  • 1




    $begingroup$
    @Crostul: I'm not so sure about the torsion part ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:39










  • $begingroup$
    OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
    $endgroup$
    – Rob Arthan
    Dec 27 '18 at 23:42
















4












$begingroup$


Does there exist an abelian group $G$ such that $G ncong H times H$ for every abelian group $H$ but $G times G times G cong K times K$ for some abelian group $K$ ?



Also see Existence of topological space which has no "square-root" but whose "cube" has a "square-root"










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
    $endgroup$
    – Crostul
    Dec 27 '18 at 1:15






  • 4




    $begingroup$
    @RobArthan: no ... I do mean what I wrote ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:38






  • 1




    $begingroup$
    @Crostul: I'm not so sure about the torsion part ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:39










  • $begingroup$
    OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
    $endgroup$
    – Rob Arthan
    Dec 27 '18 at 23:42














4












4








4


4



$begingroup$


Does there exist an abelian group $G$ such that $G ncong H times H$ for every abelian group $H$ but $G times G times G cong K times K$ for some abelian group $K$ ?



Also see Existence of topological space which has no "square-root" but whose "cube" has a "square-root"










share|cite|improve this question









$endgroup$




Does there exist an abelian group $G$ such that $G ncong H times H$ for every abelian group $H$ but $G times G times G cong K times K$ for some abelian group $K$ ?



Also see Existence of topological space which has no "square-root" but whose "cube" has a "square-root"







group-theory category-theory abelian-groups group-isomorphism group-homomorphism






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 27 '18 at 1:05









user521337user521337

1,1861417




1,1861417








  • 1




    $begingroup$
    Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
    $endgroup$
    – Crostul
    Dec 27 '18 at 1:15






  • 4




    $begingroup$
    @RobArthan: no ... I do mean what I wrote ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:38






  • 1




    $begingroup$
    @Crostul: I'm not so sure about the torsion part ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:39










  • $begingroup$
    OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
    $endgroup$
    – Rob Arthan
    Dec 27 '18 at 23:42














  • 1




    $begingroup$
    Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
    $endgroup$
    – Crostul
    Dec 27 '18 at 1:15






  • 4




    $begingroup$
    @RobArthan: no ... I do mean what I wrote ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:38






  • 1




    $begingroup$
    @Crostul: I'm not so sure about the torsion part ...
    $endgroup$
    – user521337
    Dec 27 '18 at 1:39










  • $begingroup$
    OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
    $endgroup$
    – Rob Arthan
    Dec 27 '18 at 23:42








1




1




$begingroup$
Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
$endgroup$
– Crostul
Dec 27 '18 at 1:15




$begingroup$
Structure theorem for finitely generated abelian groups clearly shows that such a group cannot be finitely generated.
$endgroup$
– Crostul
Dec 27 '18 at 1:15




4




4




$begingroup$
@RobArthan: no ... I do mean what I wrote ...
$endgroup$
– user521337
Dec 27 '18 at 1:38




$begingroup$
@RobArthan: no ... I do mean what I wrote ...
$endgroup$
– user521337
Dec 27 '18 at 1:38




1




1




$begingroup$
@Crostul: I'm not so sure about the torsion part ...
$endgroup$
– user521337
Dec 27 '18 at 1:39




$begingroup$
@Crostul: I'm not so sure about the torsion part ...
$endgroup$
– user521337
Dec 27 '18 at 1:39












$begingroup$
OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
$endgroup$
– Rob Arthan
Dec 27 '18 at 23:42




$begingroup$
OK. I just wanted to check that you didn't mean "some". "any" would be more idiomatic than "every" in this context,
$endgroup$
– Rob Arthan
Dec 27 '18 at 23:42










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