User Torsten Ekedahl

17 votes

Accepted

Unipotency in realisations of the motivic fundamental group

answered May 27, 2010 at 19:45

17 votes

Why torsion is important in (co)homology ?

answered Apr 26, 2010 at 14:46

17 votes

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Is the Characteristic of a Field Detectable from the Topology of a Topological Vector Space?

answered May 29, 2011 at 5:18

17 votes

What about the empty torsor?

answered May 29, 2011 at 17:33

17 votes

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Uniqueness of splitting field for linear representations of finite groups

answered Oct 11, 2011 at 15:08

16 votes

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Is formal smoothness a local property?

answered Apr 24, 2010 at 15:23

16 votes

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Is every homogeneous G-variety of the form G/H?

answered Apr 2, 2010 at 10:13

16 votes

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Finiteness property of automorphism scheme

answered Apr 26, 2010 at 14:01

16 votes

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Where can I easily look up / calculate (abelian) group cohomology?

answered Oct 17, 2010 at 8:43

16 votes

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Projective variety with no syzygies but not isomorphic to projective space

answered Nov 6, 2010 at 10:44

15 votes

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Complex vector bundles with trivial Chern classes on k-tori

answered Aug 11, 2010 at 14:25

15 votes

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Is the Grothendieck ring of varieties reduced?

answered Sep 27, 2010 at 16:22

15 votes

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Is a polynomial group law on $\mathbb{R}^n$ automatically nilpotent?

answered Apr 17, 2010 at 20:35

15 votes

Confusion over a point in basic category theory

answered Feb 19, 2010 at 19:05

15 votes

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$Sq^1$ cohomology of spaces

answered Aug 28, 2011 at 9:43

15 votes

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Obstructions to formally integrating vector fields in characteristic p?

answered Jul 30, 2011 at 18:21

14 votes

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Central extensions of group schemes

answered Aug 23, 2011 at 5:50

14 votes

line bundles on smooth affine variety

answered Apr 13, 2010 at 21:39

14 votes

What is a "block" in an abelian category?

answered Apr 24, 2010 at 5:33

14 votes

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What information does the completion of a stalk at its maximal ideal give us in the holomorphic, analytic, or algebraic cases?

answered Sep 12, 2010 at 10:00

14 votes

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Complex manifolds where bounded holomorphic functions are constant

answered Oct 9, 2010 at 4:52

14 votes

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Injection of Ext into H^2

answered Oct 12, 2010 at 10:20

14 votes

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Is every projective space bundle locally trivial in the Zariski topology?

answered Dec 31, 2010 at 5:48

14 votes

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Why is a general curve automorphism-free?

answered Feb 10, 2011 at 7:47

13 votes

The dual group of $\mathbb Q$

answered Aug 2, 2010 at 12:25

13 votes

Extra automorphisms of curves and definability over \bar Q

answered Apr 29, 2010 at 4:44

13 votes

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Binary Quadratic Forms in Characteristic 2

answered Mar 18, 2010 at 21:00

13 votes

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Is this a definition of equivariant derived category?

answered Jun 10, 2010 at 8:13

13 votes

Simplest example of jumping of cohomology of structure sheaf in smooth families?

answered Jul 22, 2011 at 4:45

13 votes

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"Natural" pairings between exterior powers of a vector space and its dual

answered Jun 17, 2011 at 7:37

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203 Answers

Unipotency in realisations of the motivic fundamental group

Why torsion is important in (co)homology ?

Is the Characteristic of a Field Detectable from the Topology of a Topological Vector Space?

What about the empty torsor?

Uniqueness of splitting field for linear representations of finite groups

Is formal smoothness a local property?

Is every homogeneous G-variety of the form G/H?

Finiteness property of automorphism scheme

Where can I easily look up / calculate (abelian) group cohomology?

Projective variety with no syzygies but not isomorphic to projective space

Complex vector bundles with trivial Chern classes on k-tori

Is the Grothendieck ring of varieties reduced?

Is a polynomial group law on $\mathbb{R}^n$ automatically nilpotent?

Confusion over a point in basic category theory

$Sq^1$ cohomology of spaces

Obstructions to formally integrating vector fields in characteristic p?

Central extensions of group schemes

line bundles on smooth affine variety

What is a "block" in an abelian category?

What information does the completion of a stalk at its maximal ideal give us in the holomorphic, analytic, or algebraic cases?

Complex manifolds where bounded holomorphic functions are constant

Injection of Ext into H^2

Is every projective space bundle locally trivial in the Zariski topology?

Why is a general curve automorphism-free?

The dual group of $\mathbb Q$

Extra automorphisms of curves and definability over \bar Q

Binary Quadratic Forms in Characteristic 2

Is this a definition of equivariant derived category?

Simplest example of jumping of cohomology of structure sheaf in smooth families?

"Natural" pairings between exterior powers of a vector space and its dual