User Taras Banakh

6 votes

1 answer

184 views

Classification of Polish spaces up to a $\sigma$-homeomorphism

asked Jul 22, 2022 at 21:25

6 votes

0 answers

144 views

Is there a hereditarily disconnected space which is not the union of countably many totally disconnected subspaces?

asked Jul 23, 2022 at 16:19

6 votes

1 answer

267 views

Unconditionally convergent series in $\ell_2$ consisting of $\ell_1$-small vectors

asked Oct 29, 2021 at 16:55

6 votes

1 answer

299 views

Infinite-dimensional projections of linearly independent sets

asked Nov 11, 2021 at 19:55

6 votes

2 answers

192 views

A non-Borel union of unit half-open squares

asked May 1, 2019 at 19:25

6 votes

1 answer

188 views

On continuous perturbations of functions of the first Baire class on the Cantor set

asked Sep 18, 2015 at 8:49

6 votes

0 answers

105 views

Large discrete subspaces in spaces of separately continuous functions

asked Nov 9, 2014 at 20:32

6 votes

1 answer

173 views

Can each non-open analytic subgroup of a Polish abelian group be covered by countably many closed Haar null subsets?

asked Aug 25, 2015 at 18:47

6 votes

1 answer

246 views

Is the space of countable closed covers of the Cantor set analytic?

asked Aug 22, 2016 at 17:05

6 votes

1 answer

335 views

Bernstein sets of large cardinality

asked Jun 26, 2016 at 14:08

6 votes

0 answers

180 views

The Fubini property of the $\sigma$-ideal generated by closed subsets of measure zero

asked Feb 7, 2018 at 9:53

6 votes

1 answer

449 views

Is each compact metric space a subset of a compact absolute 1-Lipschitz retract?

asked Apr 22, 2018 at 20:52

6 votes

0 answers

108 views

What is the smallest number of vertices in a graph whose every orientation contains a directed straight path of length 3

asked May 28, 2018 at 20:42

6 votes

1 answer

168 views

Are $\varepsilon$-connected components dense?

asked Aug 14, 2018 at 14:01

6 votes

0 answers

117 views

Closedness of the partial order in complete Hausdorff semitopological semilattices

asked Jun 29, 2018 at 7:24

6 votes

2 answers

411 views

A simultaneous generalization of the Grunwald-Wang and Dirichlet Theorems on primes

asked Sep 8, 2018 at 7:46

6 votes

1 answer

342 views

Is each Parovichenko compact space homeomorphic to the remainder of a soft compactification of $\mathbb N$?

asked Sep 1, 2018 at 4:40

6 votes

1 answer

246 views

A combinatorial property of uncountable groups

asked Oct 18, 2018 at 5:57

5 votes

1 answer

528 views

Base zero-dimensional spaces

asked Nov 25, 2018 at 7:08

5 votes

0 answers

128 views

Is the Baireness a 3-space property of topological groups

asked Jan 5, 2019 at 16:05

5 votes

1 answer

525 views

A name for a group with finite abelization?

asked Sep 22, 2018 at 10:53

5 votes

1 answer

287 views

Is each compactification of $\mathbb N$ soft?

asked Aug 30, 2018 at 17:30

5 votes

1 answer

332 views

Is the compact-open topology on the dual of a separable Frechet space sequential?

asked Sep 16, 2018 at 13:42

5 votes

2 answers

352 views

The cofinality of the poset $[\kappa]^{<\kappa}$ for a singular cardinal $\kappa$

asked Oct 21, 2018 at 10:18

5 votes

1 answer

241 views

On filters possessing a countable network

asked Aug 19, 2018 at 9:33

5 votes

2 answers

109 views

A reasonable topology on the group of minimal usco maps

asked Jul 12, 2018 at 11:19

5 votes

1 answer

255 views

Is the action of $SO(n)$ on the sphere $S^{n-1}$ ballanced?

asked Jul 26, 2018 at 20:29

5 votes

0 answers

117 views

$m$-thick sets with small $n$-fold sumsets in finite cyclic groups

asked Apr 30, 2018 at 5:23

5 votes

1 answer

186 views

A compact set in the plane with small sum-set and large projections

asked May 13, 2018 at 22:43

5 votes

2 answers

454 views

Is each locally compact group topology on the permutation group discrete?

asked Feb 22, 2018 at 15:07

Stack Exchange Network

351 Questions

Classification of Polish spaces up to a $\sigma$-homeomorphism

Is there a hereditarily disconnected space which is not the union of countably many totally disconnected subspaces?

Unconditionally convergent series in $\ell_2$ consisting of $\ell_1$-small vectors

Infinite-dimensional projections of linearly independent sets

A non-Borel union of unit half-open squares

On continuous perturbations of functions of the first Baire class on the Cantor set

Large discrete subspaces in spaces of separately continuous functions

Can each non-open analytic subgroup of a Polish abelian group be covered by countably many closed Haar null subsets?

Is the space of countable closed covers of the Cantor set analytic?

Bernstein sets of large cardinality

The Fubini property of the $\sigma$-ideal generated by closed subsets of measure zero

Is each compact metric space a subset of a compact absolute 1-Lipschitz retract?

What is the smallest number of vertices in a graph whose every orientation contains a directed straight path of length 3

Are $\varepsilon$-connected components dense?

Closedness of the partial order in complete Hausdorff semitopological semilattices

A simultaneous generalization of the Grunwald-Wang and Dirichlet Theorems on primes

Is each Parovichenko compact space homeomorphic to the remainder of a soft compactification of $\mathbb N$?

A combinatorial property of uncountable groups

Base zero-dimensional spaces

Is the Baireness a 3-space property of topological groups

A name for a group with finite abelization?

Is each compactification of $\mathbb N$ soft?

Is the compact-open topology on the dual of a separable Frechet space sequential?

The cofinality of the poset $[\kappa]^{<\kappa}$ for a singular cardinal $\kappa$

On filters possessing a countable network

A reasonable topology on the group of minimal usco maps

Is the action of $SO(n)$ on the sphere $S^{n-1}$ ballanced?

$m$-thick sets with small $n$-fold sumsets in finite cyclic groups

A compact set in the plane with small sum-set and large projections

Is each locally compact group topology on the permutation group discrete?