User Georges Elencwajg

36 votes

Accepted

Are morphisms from affine schemes to arbitrary schemes affine morphisms?

answered Sep 7, 2011 at 23:21

35 votes

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A geometric characterization for arithmetic genus

answered Apr 1, 2012 at 12:11

35 votes

Universal definition of tangent spaces (for schemes and manifolds)

answered Nov 5, 2009 at 10:08

35 votes

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A ring on which all finitely generated projectives modules are free but not all projectives are free?

answered Apr 1, 2010 at 21:19

34 votes

Atiyah-MacDonald, exercise 2.11

answered Oct 25, 2009 at 20:37

34 votes

Theorems for nothing (and the proofs for free)

answered Nov 13, 2009 at 20:32

33 votes

Is there another controversial statement by Grothendieck apart from 57 being prime?

answered Jan 11, 2023 at 19:15

32 votes

Life after Hartshorne (the book, not the person)...

answered Apr 13, 2011 at 8:36

32 votes

Using linear algebra to classify vector bundles over ℙ¹

answered Feb 25, 2010 at 20:45

31 votes

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Is there a Whitney theorem type theorem for projective schemes?

answered Feb 4, 2010 at 20:11

31 votes

Is there any rational curve on an Abelian variety?

answered Dec 16, 2009 at 8:31

31 votes

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Source on functorial algebraic geometry

answered Jun 27, 2011 at 19:21

31 votes

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explanation on a scheme which is not affine scheme

answered Feb 4, 2012 at 9:43

30 votes

Is there a Riemann-Roch for smooth projective curves over an arbitrary field?

answered Feb 14, 2011 at 23:04

30 votes

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The influence of string theory on mathematics for philosophers.

answered Dec 17, 2010 at 19:14

28 votes

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holomorphic K-theory

answered Mar 30, 2011 at 10:30

28 votes

Textbook for Etale Cohomology

answered Nov 10, 2011 at 23:10

27 votes

Wikipedia's definition of 'locally free sheaf'

answered Nov 4, 2010 at 22:00

27 votes

What is the relationship between being normal and being regular?

answered Apr 1, 2010 at 9:14

26 votes

Geometric meaning of the Euler sequence on $\mathbb{P}^n$ (Example 8.20.1 in Ch II of Hartshorne)

answered Nov 12, 2009 at 22:41

26 votes

Applications of the "other" definition of sheaves

answered Nov 23, 2009 at 14:00

26 votes

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generalization of Bezout's Theorem?

answered Oct 14, 2010 at 10:27

26 votes

What makes a theorem a "nullstellensatz."

answered Jan 21, 2011 at 9:54

26 votes

Are Banach Manifolds intrinsically interesting?

answered Mar 9, 2012 at 10:24

26 votes

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What should be taught in a 1st course on smooth manifolds?

answered Mar 18, 2011 at 23:29

26 votes

When do we genuinely need Noetherian conditions?

answered Dec 9, 2016 at 0:08

25 votes

A reference for geometric class field theory?

answered Aug 17, 2011 at 14:48

24 votes

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Applications of Zariski topology outside alg. geometry

answered Mar 10, 2012 at 9:08

23 votes

Serre's FAC versus Hartshorne as an introduction to sheaves in algebraic geometry

answered Nov 14, 2010 at 11:40

23 votes

Classification of finite commutative rings

answered Nov 29, 2009 at 15:32

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239 Answers

Are morphisms from affine schemes to arbitrary schemes affine morphisms?

A geometric characterization for arithmetic genus

Universal definition of tangent spaces (for schemes and manifolds)

A ring on which all finitely generated projectives modules are free but not all projectives are free?

Atiyah-MacDonald, exercise 2.11

Theorems for nothing (and the proofs for free)

Is there another controversial statement by Grothendieck apart from 57 being prime?

Life after Hartshorne (the book, not the person)...

Using linear algebra to classify vector bundles over ℙ¹

Is there a Whitney theorem type theorem for projective schemes?

Is there any rational curve on an Abelian variety?

Source on functorial algebraic geometry

explanation on a scheme which is not affine scheme

Is there a Riemann-Roch for smooth projective curves over an arbitrary field?

The influence of string theory on mathematics for philosophers.

holomorphic K-theory

Textbook for Etale Cohomology

Wikipedia's definition of 'locally free sheaf'

What is the relationship between being normal and being regular?

Geometric meaning of the Euler sequence on $\mathbb{P}^n$ (Example 8.20.1 in Ch II of Hartshorne)

Applications of the "other" definition of sheaves

generalization of Bezout's Theorem?

What makes a theorem a "nullstellensatz."

Are Banach Manifolds intrinsically interesting?

What should be taught in a 1st course on smooth manifolds?

When do we genuinely need Noetherian conditions?

A reference for geometric class field theory?

Applications of Zariski topology outside alg. geometry

Serre's FAC versus Hartshorne as an introduction to sheaves in algebraic geometry

Classification of finite commutative rings