User Taras Banakh

13 votes

0 answers

421 views

A meager subgroup of the real line, which cannot be covered by countably many closed subsets of measure zero?

asked Oct 1, 2015 at 10:57

12 votes

0 answers

372 views

Does each compact topological group admit a discontinuous homomorphism to a Polish group?

asked May 6, 2017 at 6:12

12 votes

1 answer

316 views

A reference to a theorem on the equivalence of ideals of measure zero in the Cantor cube

asked Jul 5, 2017 at 6:00

12 votes

2 answers

890 views

Factorizable groups

asked Nov 26, 2018 at 13:23

12 votes

1 answer

582 views

Is a locally finite union of $G_\delta$-sets a $G_\delta$-set?

asked Feb 23, 2018 at 11:40

12 votes

0 answers

172 views

A connected Borel subgroup of the plane

asked Jul 17, 2018 at 6:27

12 votes

1 answer

443 views

Is each cover of the plane by lines minimizable?

asked Aug 20, 2018 at 18:21

11 votes

0 answers

144 views

Characterizing compact Hausdorff spaces whose all subsets are Borel

asked Aug 13, 2018 at 10:27

11 votes

3 answers

564 views

Is each finite group multifactorizable?

asked Nov 26, 2018 at 19:08

11 votes

0 answers

541 views

Cyclic and prime factorizations of finite groups

asked Nov 28, 2018 at 20:28

11 votes

1 answer

408 views

The Parovichenko cardinal, is it equal to $\max\{\aleph_2,\mathfrak p\}$?

asked Nov 10, 2018 at 10:58

11 votes

1 answer

732 views

What is the smallest cardinality of a set A whose difference A-A contains $n$ consequtive integer numbers?

asked Feb 11, 2017 at 2:51

11 votes

2 answers

725 views

Is a Borel image of a Polish space analytic?

asked Jan 11, 2019 at 9:19

11 votes

1 answer

628 views

A new cardinal characteristic (related to partitions)?

asked Feb 3, 2020 at 9:05

11 votes

1 answer

704 views

Is $\mathfrak j_{2:1}=\mathfrak{j}_{2:2}$ in ZFC?

asked Feb 18, 2020 at 10:07

11 votes

1 answer

969 views

Why do elementary topoi have pullbacks?

asked May 29, 2020 at 18:55

11 votes

1 answer

418 views

A monotone countably cofinal function from $\omega^\omega$ to $\omega^{\omega_1}$

asked Jun 2, 2020 at 10:57

11 votes

2 answers

1k views

The Fibonacci sequence modulo $5^n$

asked May 8, 2021 at 11:15

11 votes

1 answer

228 views

The set of boundary vectors of compact convex body has empty interior

asked Mar 27, 2021 at 7:16

11 votes

3 answers

557 views

Was the small Desargues Theorem known to ancient Greeks?

asked Jul 14, 2023 at 11:47

11 votes

1 answer

390 views

Does every finite affine plane have the doubling property?

asked Sep 22, 2023 at 11:46

10 votes

1 answer

522 views

A projective plane in the Euclidean plane

asked Aug 5, 2023 at 19:27

10 votes

1 answer

355 views

Is the group of translations of an affine plane always commutative?

asked Mar 15 at 6:07

10 votes

0 answers

173 views

Is there a universal totally disconnected Polish space?

asked Jul 21, 2022 at 12:36

10 votes

1 answer

183 views

The rigidity of the countable product of free groups

asked Jul 8, 2019 at 17:00

10 votes

1 answer

326 views

What is known about topological groups of countable spread in ZFC?

asked Jan 12, 2019 at 7:54

10 votes

1 answer

350 views

What is the smallest density of a metrizable space without countable separation?

asked Jun 25, 2016 at 21:48

10 votes

1 answer

514 views

Cofinal monotone maps from $\omega^\omega$ to $\kappa^\kappa$

asked Jun 30, 2016 at 5:59

10 votes

0 answers

441 views

A new $\ell_p$-metric on the hyperspace of finite sets?

asked Jul 30, 2017 at 20:03

10 votes

1 answer

545 views

Is every metric continuum almost path-connected?

asked Aug 14, 2018 at 6:49

Stack Exchange Network

351 Questions

A meager subgroup of the real line, which cannot be covered by countably many closed subsets of measure zero?

Does each compact topological group admit a discontinuous homomorphism to a Polish group?

A reference to a theorem on the equivalence of ideals of measure zero in the Cantor cube

Factorizable groups

Is a locally finite union of $G_\delta$-sets a $G_\delta$-set?

A connected Borel subgroup of the plane

Is each cover of the plane by lines minimizable?

Characterizing compact Hausdorff spaces whose all subsets are Borel

Is each finite group multifactorizable?

Cyclic and prime factorizations of finite groups

The Parovichenko cardinal, is it equal to $\max\{\aleph_2,\mathfrak p\}$?

What is the smallest cardinality of a set A whose difference A-A contains $n$ consequtive integer numbers?

Is a Borel image of a Polish space analytic?

A new cardinal characteristic (related to partitions)?

Is $\mathfrak j_{2:1}=\mathfrak{j}_{2:2}$ in ZFC?

Why do elementary topoi have pullbacks?

A monotone countably cofinal function from $\omega^\omega$ to $\omega^{\omega_1}$

The Fibonacci sequence modulo $5^n$

The set of boundary vectors of compact convex body has empty interior

Was the small Desargues Theorem known to ancient Greeks?

Does every finite affine plane have the doubling property?

A projective plane in the Euclidean plane

Is the group of translations of an affine plane always commutative?

Is there a universal totally disconnected Polish space?

The rigidity of the countable product of free groups

What is known about topological groups of countable spread in ZFC?

What is the smallest density of a metrizable space without countable separation?

Cofinal monotone maps from $\omega^\omega$ to $\kappa^\kappa$

A new $\ell_p$-metric on the hyperspace of finite sets?

Is every metric continuum almost path-connected?