User aglearner

222 votes

8 answers

35k views

How to memorise (understand) Nakayama's lemma and its corollaries?

asked Apr 12, 2011 at 19:02

195 votes

18 answers

17k views

Great graduate courses that went online recently

asked Jan 11, 2021 at 11:14

78 votes

5 answers

14k views

Is there a "geometric" intuition underlying the notion of normal varieties?

asked Oct 11, 2012 at 17:29

56 votes

9 answers

8k views

Examples in mirror symmetry that can be understood.

asked Mar 6, 2011 at 1:00

30 votes

15 answers

6k views

Lunch seminars for PhD students

asked Oct 15, 2021 at 12:48

22 votes

6 answers

8k views

A finitely generated $\mathbb{Z}$-algebra that is a field has to be finite

asked Mar 5, 2011 at 23:55

20 votes

2 answers

2k views

The geometric median of a triangle

asked Jun 1, 2016 at 10:29

18 votes

1 answer

2k views

The group of isometries of a manifold is a Lie group, isn't it?

asked Nov 2, 2020 at 23:02

17 votes

5 answers

883 views

Rigidity of convex polyhedrons in $\mathbb R^3$ with faces removed

asked Oct 18, 2017 at 21:16

17 votes

6 answers

7k views

Explaining the concept of projective space: notes for students

asked Feb 7, 2012 at 22:29

16 votes

2 answers

4k views

A geometric reference for (affine) Gorenstein varieties and singularities

asked Mar 5, 2011 at 21:48

16 votes

2 answers

4k views

"Arithmetic genus" of a plane curve singularity.

asked Feb 23, 2013 at 14:34

15 votes

0 answers

404 views

Extending Kahler metric from a neighborhood of a divisor to the whole manifold

asked May 14, 2017 at 16:49

15 votes

1 answer

502 views

Lines passing through many points of the form $(c^n,c^m)$

asked Sep 29, 2021 at 14:35

15 votes

5 answers

2k views

Reading list for Equivariant Cohomology

asked Dec 28, 2019 at 9:03

14 votes

1 answer

826 views

An almost complex structure on $S^2\times ...\times S^2 / \mathbb{Z_2}$

asked Dec 12, 2018 at 12:55

14 votes

3 answers

1k views

Injective morphism from curves to $\mathbb CP^2$

asked Feb 22, 2013 at 17:29

14 votes

2 answers

613 views

A "holomorphic" Peano curve?

asked Nov 29, 2012 at 15:56

13 votes

1 answer

532 views

Complex curves covered by smooth plane curves

asked Jan 6, 2013 at 21:17

13 votes

4 answers

2k views

"Classical" consequences of Bezout's theorem in dimensions $>2$

asked Feb 10, 2013 at 21:59

13 votes

3 answers

1k views

How to disjoint two cycles with zero intersection?

asked Oct 1, 2011 at 20:15

13 votes

1 answer

1k views

Today's world record on the Betti numbers of Calabi-Yau three-folds.

asked Oct 24, 2012 at 12:41

13 votes

1 answer

870 views

Colourings of $\mathbb Q\times \mathbb Q$ in three colours

asked Jun 2, 2014 at 15:20

13 votes

3 answers

2k views

Linear algebra underlying quantum entanglement?

asked Mar 5, 2020 at 13:20

12 votes

3 answers

1k views

Two equivalent irreducible representations given by integer matrices

asked Jan 15, 2020 at 11:08

12 votes

1 answer

822 views

Bounds on the lowest dimension of a faithful representation of a finite group

asked Feb 4, 2020 at 20:12

12 votes

4 answers

2k views

A question on deformations of Theta divisor in the Jacobian of a complex curve

asked Apr 26, 2012 at 19:14

12 votes

9 answers

6k views

Proofs of Mordell-Weil theorem

asked Aug 7, 2011 at 15:08

11 votes

1 answer

529 views

Length decreasing homotopies of curves

asked Jan 24, 2018 at 20:18

10 votes

2 answers

526 views

Two smooth tangent almost complex curves in a $4$-manifold

asked Mar 28, 2018 at 22:24

Stack Exchange Network

209 Questions

How to memorise (understand) Nakayama's lemma and its corollaries?

Great graduate courses that went online recently

Is there a "geometric" intuition underlying the notion of normal varieties?

Examples in mirror symmetry that can be understood.

Lunch seminars for PhD students

A finitely generated $\mathbb{Z}$-algebra that is a field has to be finite

The geometric median of a triangle

The group of isometries of a manifold is a Lie group, isn't it?

Rigidity of convex polyhedrons in $\mathbb R^3$ with faces removed

Explaining the concept of projective space: notes for students

A geometric reference for (affine) Gorenstein varieties and singularities

"Arithmetic genus" of a plane curve singularity.

Extending Kahler metric from a neighborhood of a divisor to the whole manifold

Lines passing through many points of the form $(c^n,c^m)$

Reading list for Equivariant Cohomology

An almost complex structure on $S^2\times ...\times S^2 / \mathbb{Z_2}$

Injective morphism from curves to $\mathbb CP^2$

A "holomorphic" Peano curve?

Complex curves covered by smooth plane curves

"Classical" consequences of Bezout's theorem in dimensions $>2$

How to disjoint two cycles with zero intersection?

Today's world record on the Betti numbers of Calabi-Yau three-folds.

Colourings of $\mathbb Q\times \mathbb Q$ in three colours

Linear algebra underlying quantum entanglement?

Two equivalent irreducible representations given by integer matrices

Bounds on the lowest dimension of a faithful representation of a finite group

A question on deformations of Theta divisor in the Jacobian of a complex curve

Proofs of Mordell-Weil theorem

Length decreasing homotopies of curves

Two smooth tangent almost complex curves in a $4$-manifold