User Vincent

71 votes

1 answer

4k views

Is this determinant identity known?

asked May 15, 2015 at 22:31

13 votes

2 answers

795 views

Are all isomorphisms between the Fano plane and its dual of order two?

asked Jan 17, 2022 at 22:33

12 votes

1 answer

2k views

Examples of bi-implications ($\Leftrightarrow$) where the $\Rightarrow$ direction is used in the proof of the $\Leftarrow$ direction.

asked Oct 27, 2015 at 20:28

9 votes

1 answer

456 views

Meaning of "absolute zero" in set theory

asked Jan 11, 2019 at 11:57

8 votes

1 answer

2k views

Question about matrices whose row and column sums are zero

asked Dec 24, 2013 at 14:22

7 votes

2 answers

906 views

2015-related question: why are Lucas-Carmichael numbers named after Lucas?

asked Dec 31, 2014 at 3:12

7 votes

1 answer

2k views

Prime number theorem and Möbius $\mu$ function

asked Nov 2, 2018 at 13:43

7 votes

1 answer

618 views

Points on the unit circle that sum to 0

asked Nov 19, 2022 at 21:48

6 votes

1 answer

271 views

When killing rabbits doesn't stop them: a mathematical horror story

asked Jul 12, 2018 at 20:42

6 votes

2 answers

320 views

Can we describe multiplication on $\mathbb{F}_{2^n}$ as action on subsets of $n$-element set?

asked Oct 23, 2015 at 14:50

6 votes

1 answer

73 views

Does every fraction $ > 1$ occur as $\sigma(n)/n$ for some $n$?

asked Nov 24, 2016 at 21:18

5 votes

2 answers

158 views

$\lim_{s \to 1^+} 1/\zeta(s) = 0$ obvious or not?

asked Apr 18, 2022 at 21:06

5 votes

2 answers

272 views

Mystery in proof of Euclid Elements Book 7 Proposition 20

asked Apr 30, 2022 at 20:51

4 votes

1 answer

181 views

For which groups does existence of a subgroup of prime index $p$ implies the existence of a subgroup order $p$?

asked Jan 7, 2014 at 15:47

4 votes

1 answer

184 views

planarity of trivalent graphs with a cyclic ordering on the edges in each vertex

asked Feb 16, 2016 at 16:50

3 votes

1 answer

315 views

Examples of cubic graphs in which every cycle of length divisible by 3 has a chord

asked May 6, 2016 at 20:19

3 votes

1 answer

385 views

Large cycles in bridgeless cubic graphs

asked May 23, 2016 at 21:48

3 votes

1 answer

100 views

What is the name of this generalization of permanent and determinant?

asked Jul 19, 2018 at 12:43

3 votes

0 answers

57 views

Multiplicative of group of odd numbers modulo power of two [duplicate]

asked Jul 4, 2021 at 10:16

3 votes

0 answers

113 views

What can the image of a real analytic function look like?

asked Nov 22, 2019 at 9:27

3 votes

0 answers

70 views

Sequences of pairwise coprime numbers: trade-off between growth rate and simplicity?

asked May 21, 2020 at 9:05

3 votes

1 answer

97 views

Do we need really need associativity in Wedderburn's little theorem?

asked Jan 12, 2014 at 17:12

3 votes

1 answer

498 views

Are there any other integer points on the elliptic curve $Y^2 = X^3 + 1$ beyond $(-1, 0), (0, \pm 1), (2, \pm 3)$?

asked Jul 24, 2015 at 2:46

3 votes

1 answer

66 views

Some terminology involving homogeneous ideals in polynomial rings

asked Oct 24, 2022 at 22:20

3 votes

1 answer

186 views

Why does the largest square inside a triangle share a side with said triangle?

asked Apr 7, 2023 at 22:01

3 votes

3 answers

2k views

What's the best explanation of the fallacy in this 'paradox'?

asked Oct 2, 2023 at 9:48

3 votes

1 answer

167 views

Does this type of graph coloring (with multiple colors per vertex) have a name?

asked Dec 26, 2021 at 14:09

2 votes

0 answers

64 views

Pretending to be a line in a finite projective plane

asked Apr 19, 2023 at 16:26

2 votes

2 answers

58 views

Maximizing the number of parallel lines, can you beat the regular $n$-gon?

asked May 15, 2023 at 14:47

2 votes

1 answer

344 views

What does notation $U^\boxplus$ mean (where $U$ is a vector space over $\mathbb{R}$ with an action of a Lie algebra on it)?

asked May 13, 2017 at 21:15

Stack Exchange Network

54 Questions

Is this determinant identity known?

Are all isomorphisms between the Fano plane and its dual of order two?

Examples of bi-implications ($\Leftrightarrow$) where the $\Rightarrow$ direction is used in the proof of the $\Leftarrow$ direction.

Meaning of "absolute zero" in set theory

Question about matrices whose row and column sums are zero

2015-related question: why are Lucas-Carmichael numbers named after Lucas?

Prime number theorem and Möbius $\mu$ function

Points on the unit circle that sum to 0

When killing rabbits doesn't stop them: a mathematical horror story

Can we describe multiplication on $\mathbb{F}_{2^n}$ as action on subsets of $n$-element set?

Does every fraction $ > 1$ occur as $\sigma(n)/n$ for some $n$?

$\lim_{s \to 1^+} 1/\zeta(s) = 0$ obvious or not?

Mystery in proof of Euclid Elements Book 7 Proposition 20

For which groups does existence of a subgroup of prime index $p$ implies the existence of a subgroup order $p$?

planarity of trivalent graphs with a cyclic ordering on the edges in each vertex

Examples of cubic graphs in which every cycle of length divisible by 3 has a chord

Large cycles in bridgeless cubic graphs

What is the name of this generalization of permanent and determinant?

Multiplicative of group of odd numbers modulo power of two [duplicate]

What can the image of a real analytic function look like?

Sequences of pairwise coprime numbers: trade-off between growth rate and simplicity?

Do we need really need associativity in Wedderburn's little theorem?

Are there any other integer points on the elliptic curve $Y^2 = X^3 + 1$ beyond $(-1, 0), (0, \pm 1), (2, \pm 3)$?

Some terminology involving homogeneous ideals in polynomial rings

Why does the largest square inside a triangle share a side with said triangle?

What's the best explanation of the fallacy in this 'paradox'?

Does this type of graph coloring (with multiple colors per vertex) have a name?

Pretending to be a line in a finite projective plane

Maximizing the number of parallel lines, can you beat the regular $n$-gon?

What does notation $U^\boxplus$ mean (where $U$ is a vector space over $\mathbb{R}$ with an action of a Lie algebra on it)?