When can compact group actions be complexified?












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Suppose a compact (real) Lie group $K$ acts holomorphically on a complex manifold $M$. Let $G$ be the complexification of $K$. Is there a natural way to obtain an action of $G$ on $M$ extending the action of $K$?



The example of $S^1$ acting on $Delta subset mathbb{C}$ would show that this is not always possible. But this seems pathalogical in the sense that the action does complexify to an action of $mathbb{C}^*$ on $mathbb{C}$. Is this sort of behaviour the only obstruction? For example if $M$ is $mathbb{C}^n$, does the action always complexify?










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    3














    Suppose a compact (real) Lie group $K$ acts holomorphically on a complex manifold $M$. Let $G$ be the complexification of $K$. Is there a natural way to obtain an action of $G$ on $M$ extending the action of $K$?



    The example of $S^1$ acting on $Delta subset mathbb{C}$ would show that this is not always possible. But this seems pathalogical in the sense that the action does complexify to an action of $mathbb{C}^*$ on $mathbb{C}$. Is this sort of behaviour the only obstruction? For example if $M$ is $mathbb{C}^n$, does the action always complexify?










    share|cite|improve this question

























      3












      3








      3







      Suppose a compact (real) Lie group $K$ acts holomorphically on a complex manifold $M$. Let $G$ be the complexification of $K$. Is there a natural way to obtain an action of $G$ on $M$ extending the action of $K$?



      The example of $S^1$ acting on $Delta subset mathbb{C}$ would show that this is not always possible. But this seems pathalogical in the sense that the action does complexify to an action of $mathbb{C}^*$ on $mathbb{C}$. Is this sort of behaviour the only obstruction? For example if $M$ is $mathbb{C}^n$, does the action always complexify?










      share|cite|improve this question













      Suppose a compact (real) Lie group $K$ acts holomorphically on a complex manifold $M$. Let $G$ be the complexification of $K$. Is there a natural way to obtain an action of $G$ on $M$ extending the action of $K$?



      The example of $S^1$ acting on $Delta subset mathbb{C}$ would show that this is not always possible. But this seems pathalogical in the sense that the action does complexify to an action of $mathbb{C}^*$ on $mathbb{C}$. Is this sort of behaviour the only obstruction? For example if $M$ is $mathbb{C}^n$, does the action always complexify?







      differential-geometry lie-groups complex-geometry






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      asked Nov 29 at 16:27









      Curious Geometer

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