User Shaun - Mathematics Stack Exchange

246 votes

1 answer

15k views

Is this really a categorical approach to integration?

asked Mar 26, 2014 at 19:20

57 votes

1 answer

2k views

The Complexity of "The Baby Shark Song".

asked Nov 14, 2018 at 2:00

42 votes

5 answers

5k views

Fractional Calculus: Motivation and Foundations.

asked Mar 9, 2014 at 12:07

41 votes

2 answers

4k views

Category Theory and Lebesgue Integration.

asked Jan 28, 2014 at 10:58

34 votes

3 answers

2k views

Murder at Hilbert's Hotel! A study of the testimony of infinitely many suspects.

asked Oct 16, 2014 at 14:44

32 votes

3 answers

5k views

Starting sentences with mathematical symbols.

asked Mar 1, 2014 at 12:16

27 votes

4 answers

19k views

A normal subgroup is the union of conjugacy classes.

asked Mar 7, 2017 at 11:16

23 votes

6 answers

4k views

Different ways of constructing the free group over a set.

asked Jul 3, 2014 at 12:45

23 votes

2 answers

2k views

What is the intuition behind short exact sequences of groups; in particular, what is the intuition behind group extensions?

asked Apr 4, 2019 at 11:43

19 votes

2 answers

3k views

Describing the Wreath product categorically.

asked Jul 14, 2014 at 18:52

18 votes

3 answers

3k views

What, if anything, is the sum of all complex numbers?

asked Dec 25, 2018 at 16:56

17 votes

3 answers

13k views

The Best Strategy and Highest Possible Score for the "Threes!" Game.

asked Mar 18, 2014 at 17:27

16 votes

6 answers

1k views

Just How Strong is Associativity?

asked Nov 15, 2014 at 20:38

16 votes

5 answers

3k views

An Illustrated Classification of Knots.

asked Jan 16, 2015 at 21:47

15 votes

2 answers

3k views

A Drunken Prison Guard. [duplicate]

asked Mar 22, 2017 at 12:30

14 votes

1 answer

1k views

Factorise $8wxyz+w²yz+w²xz+w²xy+x²yz+x²wz+x²wy+y²xz+y²wz+y²wx+z²xy+z²wy+z²wx+w²xyz+wx²yz+wxy²z+wxyz²+xyz+wyz+wxz+wxy=0.$

asked Jul 15, 2018 at 0:26

14 votes

1 answer

1k views

What is the connection between algebraic groups and topoi?

asked Jun 13, 2023 at 23:30

13 votes

0 answers

769 views

Showing ${\rm Aut}(Q_{2^n})\cong{\rm Hol}(\Bbb Z_{2^{n-1}})$ for $n>3$

asked Jan 7, 2022 at 20:05

13 votes

3 answers

3k views

Probability and Combinatorial Group Theory.

asked Jan 9, 2018 at 23:49

13 votes

5 answers

660 views

What's the value of $n+\frac{n}{n+\frac{n}{n+\frac{n}{\ddots}}}$ for $n\in\mathbb{C}$?

asked Apr 15, 2014 at 9:22

13 votes

2 answers

3k views

Suppose $a, b\in G$ such that $\lvert a\rvert$ is odd and $aba^{-1}=b^{-1}$. Show that $b^2=e$.

asked Jan 14, 2019 at 16:33

12 votes

1 answer

2k views

Group Presentation of the Direct Product.

asked Jul 30, 2017 at 14:37

11 votes

1 answer

686 views

The Category of Small Categories: a Zoo of Functors.

asked May 9, 2014 at 20:21

11 votes

2 answers

3k views

Understanding an example of a subobject classifier.

asked Dec 9, 2013 at 17:33

11 votes

2 answers

408 views

Why is the argument on the right?

asked Apr 17, 2017 at 16:34

11 votes

6 answers

13k views

Prove that $\sqrt{2}+\sqrt{3}+\sqrt{5}$ is irrational. Generalise this. [duplicate]

asked Feb 2, 2017 at 15:08

10 votes

1 answer

325 views

The number of esquares of idempotents in the rank 2 $\mathcal{D}$-class of $M_n(\mathbb{Z}_2)$.

asked Mar 25, 2017 at 21:57

10 votes

0 answers

165 views

Is there a categorification of "(virtually) solvable"?

asked Nov 12, 2018 at 1:52

10 votes

2 answers

432 views

Under $ad-bc=1$, is every element of a finite field of the form $a^2+b^2+c^2+d^2$?

asked Feb 16, 2024 at 18:05

9 votes

1 answer

779 views

In general, how does one solve a quartic equation over a finite field?

asked Sep 19, 2024 at 18:47

Stack Exchange Network

445 Questions

Is this really a categorical approach to integration?

The Complexity of "The Baby Shark Song".

Fractional Calculus: Motivation and Foundations.

Category Theory and Lebesgue Integration.

Murder at Hilbert's Hotel! A study of the testimony of infinitely many suspects.

Starting sentences with mathematical symbols.

A normal subgroup is the union of conjugacy classes.

Different ways of constructing the free group over a set.

What is the intuition behind short exact sequences of groups; in particular, what is the intuition behind group extensions?

Describing the Wreath product categorically.

What, if anything, is the sum of all complex numbers?

The Best Strategy and Highest Possible Score for the "Threes!" Game.

Just How Strong is Associativity?

An Illustrated Classification of Knots.

A Drunken Prison Guard. [duplicate]

Factorise $8wxyz+w²yz+w²xz+w²xy+x²yz+x²wz+x²wy+y²xz+y²wz+y²wx+z²xy+z²wy+z²wx+w²xyz+wx²yz+wxy²z+wxyz²+xyz+wyz+wxz+wxy=0.$

What is the connection between algebraic groups and topoi?

Showing ${\rm Aut}(Q_{2^n})\cong{\rm Hol}(\Bbb Z_{2^{n-1}})$ for $n>3$

Probability and Combinatorial Group Theory.

What's the value of $n+\frac{n}{n+\frac{n}{n+\frac{n}{\ddots}}}$ for $n\in\mathbb{C}$?

Suppose $a, b\in G$ such that $\lvert a\rvert$ is odd and $aba^{-1}=b^{-1}$. Show that $b^2=e$.

Group Presentation of the Direct Product.

The Category of Small Categories: a Zoo of Functors.

Understanding an example of a subobject classifier.

Why is the argument on the right?

Prove that $\sqrt{2}+\sqrt{3}+\sqrt{5}$ is irrational. Generalise this. [duplicate]

The number of esquares of idempotents in the rank 2 $\mathcal{D}$-class of $M_n(\mathbb{Z}_2)$.

Is there a categorification of "(virtually) solvable"?

Under $ad-bc=1$, is every element of a finite field of the form $a^2+b^2+c^2+d^2$?

In general, how does one solve a quartic equation over a finite field?