User Taras Banakh

3 votes

0 answers

79 views

Is $\mathfrak q_0$ equal to the smallest cardinality of a second-countable $T_1$-space which is not a $Q$-space?

asked Jun 1, 2022 at 10:47

3 votes

0 answers

80 views

Every Borel linearly independent set has Borel linear hull (reference?)

asked Nov 27, 2021 at 7:03

3 votes

0 answers

31 views

Compactness of the minimal ideal of a compact Hausdorff polytopological semigroup

asked Aug 17, 2022 at 12:37

3 votes

0 answers

182 views

Is there any analogue of $\pi$ for non-Archimedean Euclidean fields?

asked Oct 30, 2022 at 20:34

3 votes

0 answers

76 views

The existence of an idempotent in some special semigroups

asked Nov 11, 2022 at 13:35

3 votes

0 answers

157 views

The "absolute" version of the Axiom Schema of Replacement in ZFC

asked Sep 14, 2022 at 22:44

3 votes

0 answers

72 views

Borel complexity of special unions of Polish spaces

asked Jan 12, 2021 at 8:32

3 votes

1 answer

156 views

What is the ideal form of an h-curve?

asked Feb 8, 2021 at 10:30

3 votes

0 answers

69 views

Non-closed trajectories in convex billiards

asked Apr 4, 2021 at 14:11

3 votes

1 answer

305 views

What corresponds to the operation of taking traces in of the Fourier transformation on a finite group?

asked Apr 7, 2021 at 5:29

3 votes

3 answers

476 views

Large product-1-free sets in finite groups

asked Jul 5, 2021 at 20:54

3 votes

0 answers

94 views

Is $\mathbb Z$ a subgroup of a nontopologizable polybounded countable group?

asked Aug 5, 2021 at 6:41

3 votes

0 answers

97 views

Are quadruples $abcd$ and $dcba$ always projectively equivalent in any projective plane?

asked Apr 7 at 13:46

3 votes

0 answers

83 views

Is every finite plane with a characteristic Desarguesian?

asked Nov 16 at 13:22

3 votes

1 answer

212 views

Another implication of the Affine Desargues Axiom

asked Sep 2, 2023 at 14:08

3 votes

1 answer

202 views

Do the heights of an acute triangle intersect at a single point (in neutral geometry)?

asked Jan 25, 2023 at 9:43

3 votes

1 answer

355 views

Extremely disconnected or extremally disconnected?

asked Oct 2, 2022 at 7:42

3 votes

1 answer

72 views

Comparing the areas of polygons via equidecomposability in the hyperbolic plane

asked Dec 17, 2022 at 4:37

2 votes

0 answers

65 views

Is the centroid property equivalent to the middle line property of the triangle?

asked Jan 5, 2023 at 22:21

2 votes

0 answers

165 views

A direct proof that every projectivity between parallel lines is affine

asked Sep 25, 2023 at 8:18

2 votes

0 answers

45 views

Are two notions of power-associativity equivalent for loops?

asked Aug 17 at 17:06

2 votes

2 answers

320 views

A graphic representation of classical unitals on 28 points

asked Nov 8, 2023 at 18:05

2 votes

1 answer

102 views

Is every Cartesian biaffine plane affine?

asked Feb 1 at 17:05

2 votes

1 answer

132 views

The separability of superextensions

asked Feb 10 at 16:38

2 votes

0 answers

81 views

The involutive structure on a division ring

asked Apr 5 at 5:49

2 votes

1 answer

154 views

Game versions of the tower number $\mathfrak t$

asked Oct 19, 2021 at 18:28

2 votes

1 answer

346 views

Are half of the $2^n$-th roots of the unit rationally independent?

asked Feb 22, 2021 at 7:56

2 votes

0 answers

190 views

What is the smallest number of nowhere dense affine subsets covering a topological group?

asked Dec 13, 2020 at 23:09

2 votes

0 answers

46 views

Finite groups whose polynomials share two common properties with polynomials on commutative groups

asked Sep 4, 2022 at 7:01

2 votes

0 answers

103 views

$n$-connected spaces (terminology)

asked Aug 31, 2022 at 6:16

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351 Questions

Is $\mathfrak q_0$ equal to the smallest cardinality of a second-countable $T_1$-space which is not a $Q$-space?

Every Borel linearly independent set has Borel linear hull (reference?)

Compactness of the minimal ideal of a compact Hausdorff polytopological semigroup

Is there any analogue of $\pi$ for non-Archimedean Euclidean fields?

The existence of an idempotent in some special semigroups

The "absolute" version of the Axiom Schema of Replacement in ZFC

Borel complexity of special unions of Polish spaces

What is the ideal form of an h-curve?

Non-closed trajectories in convex billiards

What corresponds to the operation of taking traces in of the Fourier transformation on a finite group?

Large product-1-free sets in finite groups

Is $\mathbb Z$ a subgroup of a nontopologizable polybounded countable group?

Are quadruples $abcd$ and $dcba$ always projectively equivalent in any projective plane?

Is every finite plane with a characteristic Desarguesian?

Another implication of the Affine Desargues Axiom

Do the heights of an acute triangle intersect at a single point (in neutral geometry)?

Extremely disconnected or extremally disconnected?

Comparing the areas of polygons via equidecomposability in the hyperbolic plane

Is the centroid property equivalent to the middle line property of the triangle?

A direct proof that every projectivity between parallel lines is affine

Are two notions of power-associativity equivalent for loops?

A graphic representation of classical unitals on 28 points

Is every Cartesian biaffine plane affine?

The separability of superextensions

The involutive structure on a division ring

Game versions of the tower number $\mathfrak t$

Are half of the $2^n$-th roots of the unit rationally independent?

What is the smallest number of nowhere dense affine subsets covering a topological group?

Finite groups whose polynomials share two common properties with polynomials on commutative groups

$n$-connected spaces (terminology)