meta user
network profile
| bio | website | |
|---|---|---|
| location | Venice, Italy | |
| age | 25 | |
| visits | member for | 2 years, 6 months |
| seen | 7 hours ago | |
| stats | profile views | 55 |
Master student in mathematics at the University of Amsterdam
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15h |
asked | Generators for the sheaf of regular functions |
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21h |
answered | Possible description of closed subset of a projective variety |
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22h |
asked | Possible description of closed subset of a projective variety |
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May 16 |
comment |
Closed subset of an affine variety… is it affine? Thank you very much, I think my confusion was arising exactly from this point! |
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May 16 |
comment |
Closed subset of an affine variety… is it affine? Ok, thanks for your further explanation. Nevertheless, Georges argument really reads like "closed in affine is affine". This wrong interpretation of his answer is my fault then, I apologize |
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May 16 |
revised |
Closed subset of an affine variety… is it affine? added 83 characters in body |
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May 16 |
comment |
Closed subset of an affine variety… is it affine? Here's the reason: he says << the subvariety $X1×{a2}⊂X1×X2$ is closed in the affine variety $X1×X2$ and is thus affine >>. It may be that in this particular example the claim holds, but it sounds like a fact that is true in general |
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May 16 |
revised |
Closed subset of an affine variety… is it affine? added 59 characters in body |
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May 16 |
comment |
Closed subset of an affine variety… is it affine? So this answer ( math.stackexchange.com/a/389399/3416 ) , given by a user with more that 44k reputation and which got 6 upvotes, is wrong? |
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May 16 |
asked | Closed subset of an affine variety… is it affine? |
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May 14 |
awarded | Caucus |
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May 13 |
awarded | Nice Question |
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May 12 |
awarded | Yearling |
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May 12 |
accepted | Product of two algebraic varieties is affine… are the two varieties affine? |
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May 12 |
asked | Product of two algebraic varieties is affine… are the two varieties affine? |
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May 5 |
comment |
Do fiber and structure group determine the fiber bundle over a given space? What do you mean by BG? |
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May 5 |
comment |
Do fiber and structure group determine the fiber bundle over a given space? Could you please expand this and describe the transition functions of each case? That would be really useful! |
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May 5 |
comment |
Do fiber and structure group determine the fiber bundle over a given space? Thanks, now I see it! But what happens if we also fix the transition functions? Do we have a unique bundle then? |
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May 4 |
comment |
Do fiber and structure group determine the fiber bundle over a given space? For a covering space yes, the structure group is the group of deck transformations. But this group depends on the action of the fundamental group of B on the total space. Considering the non connected, trivial double cover of $S^1$ ($E$=disjoint union of two circles) the action of the fundamental group on $E$ is trivial (go around the circle and come back to the starting point) and $G$ is the trivial group. Considering the connected, non trivial double cover of $S^1$ ($E=S^1$) the action of the fundamental group on $E$ is non trivial (go up and go down on the spiral) and $G=\mathbb{Z}_2$. |
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May 4 |
comment |
Do fiber and structure group determine the fiber bundle over a given space? Do they have the same structure group? |
