User Dominic van der Zypen

62 votes

7 answers

10k views

In what respect are univalent foundations "better" than set theory?

asked Nov 24, 2017 at 15:03

41 votes

2 answers

1k views

Continuity-minimal topologies

asked Mar 4, 2025 at 9:02

39 votes

10 answers

6k views

Decision problems for which it is unknown whether they are decidable

asked Nov 6, 2019 at 15:57

37 votes

4 answers

2k views

Connectedness in the language of path-connectedness

asked Mar 24, 2015 at 7:01

31 votes

2 answers

2k views

Is $\mathbb{R}\cong\text{Cont}(X,Y)$ for some non-trivial spaces $X,Y$?

asked Jan 8, 2018 at 8:09

27 votes

2 answers

2k views

Runner's High (Speed)

asked Dec 5, 2018 at 12:47

26 votes

2 answers

3k views

Question on a generalisation of a theorem by Euler

asked Jun 16, 2018 at 10:38

25 votes

3 answers

1k views

What spaces $X$ do have $\text{End}(X) \cong \text{End}(\mathbb{R})$?

asked Mar 29, 2020 at 15:07

23 votes

2 answers

3k views

Does the "three-set-lemma" imply the Axiom of Choice?

asked Apr 20, 2020 at 12:12

23 votes

4 answers

2k views

Are infinite groups in which most elements have order $\leq 2$ commutative?

asked Sep 18, 2018 at 6:09

23 votes

0 answers

1k views

Is the set of integers of the form $a/(b+c)+b/(a+c)+c/(a+b)$ computable?

asked Aug 14, 2017 at 19:16

22 votes

2 answers

772 views

$\kappa$-homogeneous topological spaces

asked Jul 28, 2016 at 12:50

21 votes

1 answer

564 views

"Good" edge-colorings

asked Feb 12, 2017 at 15:59

21 votes

3 answers

1k views

Does the hypergraph of subgroups determine a group?

asked Oct 6, 2018 at 13:47

21 votes

1 answer

714 views

Almost orthogonal maps $f:\omega \to \{-1,1\}$

asked Aug 30, 2024 at 6:44

19 votes

4 answers

1k views

Generalization of a mind-boggling box-opening puzzle

asked Oct 19, 2024 at 9:42

19 votes

2 answers

1k views

Is the powerset graph construction injective?

asked May 18, 2025 at 10:20

19 votes

3 answers

1k views

"Anti" fixed point property

asked Nov 11, 2017 at 9:15

19 votes

3 answers

2k views

Non-homeomorphic spaces such that taking away a point makes them homeomorphic

asked Aug 4, 2015 at 8:49

18 votes

1 answer

721 views

Aperiodic monotile in $\mathbb{R}$

asked Mar 24, 2023 at 9:36

18 votes

3 answers

946 views

Possible cardinalities of maximal chains in ${\cal P}(\omega)$

asked Sep 7, 2025 at 20:37

18 votes

2 answers

978 views

The golden ratio equation in terms of functions $f:\mathbb{N}\to\mathbb{N}$

asked Dec 26, 2024 at 17:55

17 votes

4 answers

2k views

Uniquely representing finite sets of integers by an intersection of infinite sets

asked Jun 15, 2025 at 17:28

17 votes

1 answer

1k views

Does the set of square numbers adhere to Benford's law in every base?

asked Dec 21, 2022 at 13:19

17 votes

1 answer

2k views

Parity and the Axiom of Choice

asked Sep 3, 2023 at 19:03

17 votes

1 answer

1k views

Fraction of $S_n$ reachable by using every transposition once as $n\to\infty$?

asked Feb 12, 2022 at 15:54

17 votes

2 answers

1k views

"Insanely increasing" $C^\infty$ function with upper bound

asked Nov 26, 2018 at 17:31

17 votes

1 answer

843 views

Strongly rigid Hausdorff spaces

asked Dec 3, 2014 at 12:36

16 votes

3 answers

2k views

Is $\mathrm{Graph}$ cartesian-closed?

asked Jan 28, 2019 at 15:21

16 votes

5 answers

1k views

Algorithm for selecting a fixed-point free permutation $\varphi:\{1,\ldots,n\}\to\{1,\ldots,n\}$

asked Nov 19, 2025 at 13:25

Stack Exchange Network

1,299 Questions

In what respect are univalent foundations "better" than set theory?

Continuity-minimal topologies

Decision problems for which it is unknown whether they are decidable

Connectedness in the language of path-connectedness

Is $\mathbb{R}\cong\text{Cont}(X,Y)$ for some non-trivial spaces $X,Y$?

Runner's High (Speed)

Question on a generalisation of a theorem by Euler

What spaces $X$ do have $\text{End}(X) \cong \text{End}(\mathbb{R})$?

Does the "three-set-lemma" imply the Axiom of Choice?

Are infinite groups in which most elements have order $\leq 2$ commutative?

Is the set of integers of the form $a/(b+c)+b/(a+c)+c/(a+b)$ computable?

$\kappa$-homogeneous topological spaces

"Good" edge-colorings

Does the hypergraph of subgroups determine a group?

Almost orthogonal maps $f:\omega \to \{-1,1\}$

Generalization of a mind-boggling box-opening puzzle

Is the powerset graph construction injective?

"Anti" fixed point property

Non-homeomorphic spaces such that taking away a point makes them homeomorphic

Aperiodic monotile in $\mathbb{R}$

Possible cardinalities of maximal chains in ${\cal P}(\omega)$

The golden ratio equation in terms of functions $f:\mathbb{N}\to\mathbb{N}$

Uniquely representing finite sets of integers by an intersection of infinite sets

Does the set of square numbers adhere to Benford's law in every base?

Parity and the Axiom of Choice

Fraction of $S_n$ reachable by using every transposition once as $n\to\infty$?

"Insanely increasing" $C^\infty$ function with upper bound

Strongly rigid Hausdorff spaces

Is $\mathrm{Graph}$ cartesian-closed?

Algorithm for selecting a fixed-point free permutation $\varphi:\{1,\ldots,n\}\to\{1,\ldots,n\}$