When does contractible space of almost complex structures taming a given symplectic form $omega$ contain an...











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Given a symplectic form $omega$ on a compact symplectic manifold $X$, we know there is a contractible homotopy class $mathcal{J}_{omega}$ of almost complex structures that tame $omega$. A subset of these is also compatible with $omega$, in that $omega(cdot, Jcdot cdot)$ defines a Riemannian metric on the manifold. How do know, other than things like odd Betti numbers being even, if $omega$ has an integrable member $J_{omega, int}$ of $mathcal{J}_{omega}$, so that $(X,omega, J_{omega, int}, omega(cdot, J_{omega, int}cdot cdot))$ is a Kaehler manifold?










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    Given a symplectic form $omega$ on a compact symplectic manifold $X$, we know there is a contractible homotopy class $mathcal{J}_{omega}$ of almost complex structures that tame $omega$. A subset of these is also compatible with $omega$, in that $omega(cdot, Jcdot cdot)$ defines a Riemannian metric on the manifold. How do know, other than things like odd Betti numbers being even, if $omega$ has an integrable member $J_{omega, int}$ of $mathcal{J}_{omega}$, so that $(X,omega, J_{omega, int}, omega(cdot, J_{omega, int}cdot cdot))$ is a Kaehler manifold?










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      Given a symplectic form $omega$ on a compact symplectic manifold $X$, we know there is a contractible homotopy class $mathcal{J}_{omega}$ of almost complex structures that tame $omega$. A subset of these is also compatible with $omega$, in that $omega(cdot, Jcdot cdot)$ defines a Riemannian metric on the manifold. How do know, other than things like odd Betti numbers being even, if $omega$ has an integrable member $J_{omega, int}$ of $mathcal{J}_{omega}$, so that $(X,omega, J_{omega, int}, omega(cdot, J_{omega, int}cdot cdot))$ is a Kaehler manifold?










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      Given a symplectic form $omega$ on a compact symplectic manifold $X$, we know there is a contractible homotopy class $mathcal{J}_{omega}$ of almost complex structures that tame $omega$. A subset of these is also compatible with $omega$, in that $omega(cdot, Jcdot cdot)$ defines a Riemannian metric on the manifold. How do know, other than things like odd Betti numbers being even, if $omega$ has an integrable member $J_{omega, int}$ of $mathcal{J}_{omega}$, so that $(X,omega, J_{omega, int}, omega(cdot, J_{omega, int}cdot cdot))$ is a Kaehler manifold?







      general-topology differential-geometry symplectic-geometry kahler-manifolds almost-complex






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      asked Mar 3 '16 at 20:53









      Sinister Cutlass

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          There are LOTS of additional obstructions (for example, not every finitely presented group whose abelianization has even rank is a fundamental group of a Kaehler manifold). Most of the known obstructions are listed, for example, here.






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            There are LOTS of additional obstructions (for example, not every finitely presented group whose abelianization has even rank is a fundamental group of a Kaehler manifold). Most of the known obstructions are listed, for example, here.






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              There are LOTS of additional obstructions (for example, not every finitely presented group whose abelianization has even rank is a fundamental group of a Kaehler manifold). Most of the known obstructions are listed, for example, here.






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                There are LOTS of additional obstructions (for example, not every finitely presented group whose abelianization has even rank is a fundamental group of a Kaehler manifold). Most of the known obstructions are listed, for example, here.






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                There are LOTS of additional obstructions (for example, not every finitely presented group whose abelianization has even rank is a fundamental group of a Kaehler manifold). Most of the known obstructions are listed, for example, here.







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                answered Nov 16 at 9:41









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