User Dominik

224 votes

2 answers

8k views

Is there a 0-1 law for the theory of groups?

asked Jun 30, 2013 at 20:26

191 votes

5 answers

7k views

A Topology such that the continuous functions are exactly the polynomials

general-topology polynomials continuity

asked Jun 23, 2013 at 16:00

63 votes

2 answers

30k views

Is Serge Lang's Algebra still worth reading?

abstract-algebra reference-request

asked Apr 7, 2013 at 20:41

48 votes

2 answers

4k views

Is every group the automorphism group of a group?

group-theory examples-counterexamples abstract-algebra

asked Dec 8, 2012 at 19:02

34 votes

3 answers

5k views

Why should "graph theory be part of the education of every student of mathematics"?

graph-theory soft-question advice

asked Apr 26, 2013 at 20:35

33 votes

2 answers

1k views

Is $ \pi $ definable in $(\Bbb R,0,1,+,×, <,\exp) $?

real-analysis model-theory first-order-logic

asked Jun 9, 2013 at 22:50

30 votes

4 answers

3k views

If two non-overlapping squares inside a unit square have side lengths $a$ and $b$, prove that $a+b \le 1$.

euclidean-geometry packing-problem

asked Nov 25, 2012 at 19:42

23 votes

4 answers

2k views

What are the important theorems in the theory of dynamical systems?

dynamical-systems

asked May 10, 2013 at 20:52

23 votes

1 answer

943 views

Is $\Bbb R$ definable in $(\Bbb C,0,1,+,*,\exp)$?

logic model-theory first-order-logic

asked Jun 12, 2013 at 16:04

19 votes

3 answers

2k views

Are there interesting rings without unity?

soft-question ring-theory examples-counterexamples

asked May 5, 2013 at 17:31

19 votes

1 answer

2k views

Is the space of smooth sections of a vector bundle finitely generated as a $C^\infty$-module?

differential-geometry vector-bundles

asked Apr 10, 2014 at 15:01

17 votes

1 answer

654 views

How confident can we be about the validity of the classification of finite simple groups?

group-theory soft-question finite-groups simple-groups

asked Apr 1, 2013 at 23:35

16 votes

3 answers

3k views

Presentation of Rubik's Cube group

group-theory finite-groups group-presentation rubiks-cube

asked Dec 2, 2012 at 21:14

16 votes

5 answers

3k views

Most astonishing applications of compactness theorem outside logic

logic model-theory compactness big-list first-order-logic

asked Jun 7, 2013 at 12:20

16 votes

1 answer

2k views

What are some examples of hard theorems in category theory?

soft-question category-theory examples-counterexamples big-list

asked Jan 6, 2014 at 18:59

16 votes

1 answer

248 views

Is almost any group generated by two generators?

group-theory finite-groups asymptotics group-presentation finitely-generated

asked Jul 26, 2013 at 20:51

15 votes

2 answers

939 views

Etymology of Tor and Ext Functors

notation category-theory terminology homological-algebra

asked Jul 1, 2013 at 16:54

15 votes

1 answer

788 views

A finite first order theory whose finite models are exactly the $\Bbb F_p$?

logic field-theory finite-fields model-theory first-order-logic

asked Jun 20, 2013 at 8:44

13 votes

4 answers

2k views

Counterexamples in complex analysis

complex-analysis big-list examples-counterexamples

asked Dec 9, 2012 at 11:48

13 votes

2 answers

2k views

Characteristic polynomial of a matrix with zeros on its diagonal

linear-algebra matrices

asked Dec 22, 2012 at 19:19

13 votes

3 answers

333 views

An explicit imbedding of $(R\mathbf{-Mod})^{op}$ into $S\mathbf{-Mod}$

category-theory modules homological-algebra abelian-categories

asked Jan 6, 2014 at 18:51

12 votes

2 answers

1k views

Does every ring with unity arise as an endomorphism ring?

abstract-algebra ring-theory abelian-groups

asked Dec 8, 2012 at 22:44

11 votes

1 answer

544 views

Are there exotic symplectic structures on $ S^2 $?

differential-geometry surfaces spherical-geometry symplectic-geometry

asked Jul 21, 2013 at 13:10

10 votes

1 answer

584 views

The smallest group with 3 generators

group-theory finite-groups

asked Jul 26, 2013 at 19:59

10 votes

3 answers

7k views

Do negative dimensions make sense? [duplicate]

dimension-theory-analysis

asked Jun 18, 2013 at 19:12

10 votes

1 answer

400 views

Proving a geometric inequality without Lagrange multipliers

algebra-precalculus inequality

asked Jun 12, 2013 at 17:02

10 votes

1 answer

287 views

Is there a universal property for the ultraproduct?

category-theory model-theory nonstandard-analysis

asked Jun 17, 2013 at 18:54

10 votes

2 answers

699 views

Area enclosed by 2-dimensional random curve

stochastic-processes brownian-motion stochastic-integrals stochastic-analysis

asked Dec 5, 2012 at 22:13

10 votes

1 answer

248 views

Universal property characterizing $\Bbb R$

category-theory examples-counterexamples

asked Apr 10, 2013 at 21:27

10 votes

1 answer

303 views

Maps of $\mathbb{R}^3$ commuting with the cross product

geometry analytic-geometry functional-equations cross-product

asked Jan 25, 2013 at 14:28

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91 Questions

Is there a 0-1 law for the theory of groups?

A Topology such that the continuous functions are exactly the polynomials

Is Serge Lang's Algebra still worth reading?

Is every group the automorphism group of a group?

Why should "graph theory be part of the education of every student of mathematics"?

Is $ \pi $ definable in $(\Bbb R,0,1,+,×, <,\exp) $?

If two non-overlapping squares inside a unit square have side lengths $a$ and $b$, prove that $a+b \le 1$.

What are the important theorems in the theory of dynamical systems?

Is $\Bbb R$ definable in $(\Bbb C,0,1,+,*,\exp)$?

Are there interesting rings without unity?

Is the space of smooth sections of a vector bundle finitely generated as a $C^\infty$-module?

How confident can we be about the validity of the classification of finite simple groups?

Presentation of Rubik's Cube group

Most astonishing applications of compactness theorem outside logic

What are some examples of hard theorems in category theory?

Is almost any group generated by two generators?

Etymology of Tor and Ext Functors

A finite first order theory whose finite models are exactly the $\Bbb F_p$?

Counterexamples in complex analysis

Characteristic polynomial of a matrix with zeros on its diagonal

An explicit imbedding of $(R\mathbf{-Mod})^{op}$ into $S\mathbf{-Mod}$

Does every ring with unity arise as an endomorphism ring?

Are there exotic symplectic structures on $ S^2 $?

The smallest group with 3 generators

Do negative dimensions make sense? [duplicate]

Proving a geometric inequality without Lagrange multipliers

Is there a universal property for the ultraproduct?

Area enclosed by 2-dimensional random curve

Universal property characterizing $\Bbb R$

Maps of $\mathbb{R}^3$ commuting with the cross product