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#1 2013-11-30 07:14:15

Bryan29
Guest

Short exact sequence

I'm from a foreign country, I don't speak well English. Sorry.

My question is :
$X$ and $Y$ are subvarieties of a smooth projective variety $M$ such that $M=X \bigcup Y$. I would like to know if we can construct a short exact sequence $$ \mathrm{Hdg}_k ( X \bigcap Y ) \to \mathrm{Hdg}_k ( X ) \oplus \mathrm{Hdg}_k ( Y ) \to \mathrm{Hdg}_k ( X \bigcup Y ) \to 0 $$ such that $ \mathrm{Hdg}_k ( X ) = H^{k,k} ( X ) \bigcap H^{2k} ( X , \mathbb{Q} ) $ is the group of Hodge classes.
Can you tell me if you know some references about this subject?

Thanks a lot.

#2 2013-11-30 14:32:37

anonimnystefy
Real Member

Offline

Re: Short exact sequence

Hi Bryan29

Welcom to the forum! smile

You might want to use

Code:

[math][/math]

instead of $$.


The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
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