User user717

83 votes

6 answers

16k views

What is a cohomology theory (seriously)?

asked Nov 19, 2009 at 16:26

45 votes

6 answers

6k views

Universal definition of tangent spaces (for schemes and manifolds)

asked Nov 4, 2009 at 22:47

38 votes

5 answers

11k views

Definitions of Hecke algebras

asked Nov 7, 2009 at 18:45

37 votes

6 answers

6k views

Why is Milnor K-theory not ad hoc?

asked Nov 5, 2009 at 11:31

29 votes

6 answers

3k views

Errata database?

asked Oct 28, 2009 at 12:41

29 votes

10 answers

5k views

How can I really motivate the Zariski topology on a scheme?

asked Dec 8, 2009 at 16:26

15 votes

3 answers

6k views

Simultaneous diagonalization

asked Dec 22, 2009 at 14:38

15 votes

8 answers

2k views

How can I conclude that I live in a solar system?

asked Feb 6, 2010 at 22:39

15 votes

3 answers

2k views

What are the motivations for studying Cherednik (symplectic reflection, graded Hecke) algebras?

asked Apr 29, 2010 at 9:36

11 votes

1 answer

2k views

Realizations and pinnings (épinglages) of reductive groups

asked Mar 9, 2010 at 10:28

8 votes

2 answers

1k views

(Non-trivial) presentation of general linear and symplectic group over Z/mZ?

asked Nov 22, 2009 at 13:08

7 votes

2 answers

810 views

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

asked Apr 2, 2010 at 9:43

6 votes

2 answers

2k views

Classification of finite complex reflection groups

asked Jun 22, 2010 at 8:38

5 votes

0 answers

1k views

Dualizing sheaf on a Cohen-Macaulay variety

asked Jul 19, 2010 at 19:10

4 votes

1 answer

412 views

F_q-structures on schemes

asked Jan 17, 2010 at 12:30

4 votes

1 answer

5k views

Confusing definitions in Liu's Algebraic geometry and arithmetic curves?

asked Jul 18, 2010 at 12:13

4 votes

1 answer

335 views

"Eigenvalue characters"

asked Dec 23, 2009 at 11:18

3 votes

3 answers

3k views

Proof of Steinberg's tensor product theorem

asked Jan 6, 2010 at 17:24

3 votes

0 answers

487 views

Is the Cartan matrix a complete invariant of a Kac-Moody algebra?

asked Feb 25, 2010 at 10:29

3 votes

2 answers

732 views

If the morphism of root data induced by an isogeny of a reductive group is a Frobenius, is then the isogeny itself a Frobenius?

asked Mar 5, 2010 at 22:17

3 votes

2 answers

695 views

Automorphisms of the totally ordered group $\mathbb{Z}{^n}$ with lexicographical order

asked Nov 2, 2009 at 14:28

2 votes

2 answers

718 views

Algebra / unital associative algebra: better terminology?

asked Feb 12, 2010 at 14:28

2 votes

1 answer

264 views

Formal deformations of algebras over not necessarily commutative rings

asked Apr 19, 2010 at 21:04

2 votes

2 answers

302 views

How canonical is the triangular decomposition of a rational Cherednik algebra?

asked Jul 28, 2010 at 14:55

1 vote

1 answer

1k views

Neukirch's class field axiom and cohomology of units for unramified extension

asked Oct 26, 2009 at 13:29

0 votes

2 answers

563 views

Primary decomposition of zero-dimensional modules

asked Feb 14, 2010 at 16:57

Stack Exchange Network

26 Questions

What is a cohomology theory (seriously)?

Universal definition of tangent spaces (for schemes and manifolds)

Definitions of Hecke algebras

Why is Milnor K-theory not ad hoc?

Errata database?

How can I really motivate the Zariski topology on a scheme?

Simultaneous diagonalization

How can I conclude that I live in a solar system?

What are the motivations for studying Cherednik (symplectic reflection, graded Hecke) algebras?

Realizations and pinnings (épinglages) of reductive groups

(Non-trivial) presentation of general linear and symplectic group over Z/mZ?

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

Classification of finite complex reflection groups

Dualizing sheaf on a Cohen-Macaulay variety

F_q-structures on schemes

Confusing definitions in Liu's Algebraic geometry and arithmetic curves?

"Eigenvalue characters"

Proof of Steinberg's tensor product theorem

Is the Cartan matrix a complete invariant of a Kac-Moody algebra?

If the morphism of root data induced by an isogeny of a reductive group is a Frobenius, is then the isogeny itself a Frobenius?

Automorphisms of the totally ordered group $\mathbb{Z}{^n}$ with lexicographical order

Algebra / unital associative algebra: better terminology?

Formal deformations of algebras over not necessarily commutative rings

How canonical is the triangular decomposition of a rational Cherednik algebra?

Neukirch's class field axiom and cohomology of units for unramified extension

Primary decomposition of zero-dimensional modules