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Can someone provide examples of Kähler manifolds which are not algebraic?

This question came to my mind seeing the post of Andrea Ferretti.

flag	asked Jan 29 2010 at 20:34 Anweshi 4,246●2●25●56

Mohan Ramachandran · Accepted Answer · 2010-01-29 20:53:59Z UTC

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generic complex tori in complex dimension 2 or higher. MR

answered Jan 29 2010 at 20:53

Mohan Ramachandran
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	You mean those which are not Abelian Varieties? Thanks! – Anweshi Jan 29 2010 at 20:55
	yes that is what I meant.MR – Mohan Ramachandran Jan 29 2010 at 21:04
	ramachndran ==> ramachandran? – Anweshi Jan 30 2010 at 14:32

jvp · Answer 2 · 2010-01-29 22:44:28Z UTC

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You might want to take a look at this previous MO question.

There, I mentioned Voisin's results disproving Kodaira's conjecture (every Kahler manifold is deformation equivalent to a projective manifold).

answered Jan 29 2010 at 22:44

jvp
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Andrei Halanay · Answer 3 · 2010-01-29 21:05:00Z UTC

In (complex) dimension greater or equal with 2 there are complex tori which are not algebraic. A criterion for projectivity is that of Riemann (see http://en.wikipedia.org/wiki/Abelian_variety#Riemann_conditions). Also there are K3 surfaces which are not algebraic.

Pete L. Clark · Answer 4 · 2010-01-29 21:34:17Z UTC

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It doesn't in itself give specific examples, but the theoretical answer to the question "When is a compact Kahler manifold algebraic?" is given by the Kodaira embedding theorem. A nice exposition is given in Richard Wells' Differential Analysis on Complex Manifolds. Indeed, the KET is the crescendo to which the entire book builds.

answered Jan 29 2010 at 21:34

Pete L. Clark
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Thanks. This is helpful. As it must have been obvious from the question, I knew dear nothing about Kahler manifold beyond their definition, and an awareness of their importance. – Anweshi Jan 29 2010 at 21:36

Kähler manifold which is not algebraic

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