Degree of universal cover of simple Lie group












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$begingroup$


I have seen a statement that if $mathfrak{g}$ is a simple Lie algebra, then there are only finitely many Lie groups with Lie algebra $mathfrak{g}$. Equivalently, the simply connected group with Lie algebra $mathfrak{g}$ has finite center. Equivalently, the fundamental group of a Lie group with Lie algebra $mathfrak{g}$ is finite.



Can anyone provide a proof or reference for any of these equivalent statements?










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$endgroup$












  • $begingroup$
    See this question and the linked questions and references, which together give the result.
    $endgroup$
    – Dietrich Burde
    Jan 17 at 15:41












  • $begingroup$
    Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
    $endgroup$
    – user320832
    Jan 18 at 5:35
















1












$begingroup$


I have seen a statement that if $mathfrak{g}$ is a simple Lie algebra, then there are only finitely many Lie groups with Lie algebra $mathfrak{g}$. Equivalently, the simply connected group with Lie algebra $mathfrak{g}$ has finite center. Equivalently, the fundamental group of a Lie group with Lie algebra $mathfrak{g}$ is finite.



Can anyone provide a proof or reference for any of these equivalent statements?










share|cite|improve this question









$endgroup$












  • $begingroup$
    See this question and the linked questions and references, which together give the result.
    $endgroup$
    – Dietrich Burde
    Jan 17 at 15:41












  • $begingroup$
    Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
    $endgroup$
    – user320832
    Jan 18 at 5:35














1












1








1





$begingroup$


I have seen a statement that if $mathfrak{g}$ is a simple Lie algebra, then there are only finitely many Lie groups with Lie algebra $mathfrak{g}$. Equivalently, the simply connected group with Lie algebra $mathfrak{g}$ has finite center. Equivalently, the fundamental group of a Lie group with Lie algebra $mathfrak{g}$ is finite.



Can anyone provide a proof or reference for any of these equivalent statements?










share|cite|improve this question









$endgroup$




I have seen a statement that if $mathfrak{g}$ is a simple Lie algebra, then there are only finitely many Lie groups with Lie algebra $mathfrak{g}$. Equivalently, the simply connected group with Lie algebra $mathfrak{g}$ has finite center. Equivalently, the fundamental group of a Lie group with Lie algebra $mathfrak{g}$ is finite.



Can anyone provide a proof or reference for any of these equivalent statements?







lie-groups lie-algebras covering-spaces fundamental-groups






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 16 at 18:00









user320832user320832

1707




1707












  • $begingroup$
    See this question and the linked questions and references, which together give the result.
    $endgroup$
    – Dietrich Burde
    Jan 17 at 15:41












  • $begingroup$
    Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
    $endgroup$
    – user320832
    Jan 18 at 5:35


















  • $begingroup$
    See this question and the linked questions and references, which together give the result.
    $endgroup$
    – Dietrich Burde
    Jan 17 at 15:41












  • $begingroup$
    Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
    $endgroup$
    – user320832
    Jan 18 at 5:35
















$begingroup$
See this question and the linked questions and references, which together give the result.
$endgroup$
– Dietrich Burde
Jan 17 at 15:41






$begingroup$
See this question and the linked questions and references, which together give the result.
$endgroup$
– Dietrich Burde
Jan 17 at 15:41














$begingroup$
Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
$endgroup$
– user320832
Jan 18 at 5:35




$begingroup$
Thanks for pointing me there! But the first answer is only for compact Lie groups, and I certainly hope I don’t need to use Ricci curvature like in the second answer. (And the links in the comments are broken.)
$endgroup$
– user320832
Jan 18 at 5:35










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