User Saúl RM

42 votes

2 answers

2k views

How decreasing can a bijection $f:\mathbb{N}\to\mathbb{N}$ be?

asked Jun 13 at 23:52

40 votes

2 answers

2k views

Can the nth projective space be covered by n charts?

asked Nov 26, 2021 at 1:57

25 votes

1 answer

1k views

Is there an open subset $A$ of $[0,1]^2$ with measure $>\frac{1}{100}$ that satisfies this property?

asked May 13, 2022 at 23:46

23 votes

2 answers

1k views

Can we make distances in a finite subset of a manifold whatever we want?

asked Mar 10, 2022 at 17:11

12 votes

0 answers

288 views

Are there $n$ points dividing a compact Riemannian manifold into equal regions?

asked Dec 31, 2022 at 17:27

11 votes

1 answer

500 views

Uncountable families of measurable sets with pairwise positive intersections

asked Nov 1 at 21:17

7 votes

2 answers

180 views

Bisector of two points in a Riemannian manifold has measure $0$

asked Jan 3, 2023 at 13:22

7 votes

2 answers

562 views

Is the union of a compact and the relatively compact components of its complementary in a manifold compact?

asked Dec 5, 2021 at 10:09

5 votes

0 answers

113 views

Stronger form of countable dense homogeneity

asked Jun 20, 2021 at 22:53

5 votes

0 answers

108 views

Non-monotileable amenable groups

asked Apr 21 at 16:49

4 votes

1 answer

211 views

Nonempty intersection of cosets of finite-index subgroups

asked Nov 7, 2023 at 1:26

4 votes

1 answer

292 views

Is every 1-Lipschitz homeomorphism $f:X\to X$ from a compact metric space to itself an isometry?

asked Feb 25, 2023 at 22:11

4 votes

0 answers

359 views

If a derivative is defined everywhere and $\pm1$ almost everywhere, is it constant?

asked Dec 14, 2022 at 21:11

3 votes

1 answer

130 views

Do sets of big returns contain sets of returns?

asked Oct 23 at 3:43

3 votes

0 answers

157 views

Growth of the constants from the Stone-Weierstrass Theorem

asked Mar 11, 2023 at 23:38

3 votes

1 answer

229 views

Maximum cardinality of separated sets in the Hamming distance

asked Apr 11, 2023 at 19:59

2 votes

0 answers

257 views

Sum of roots of unity

asked Jun 11, 2023 at 1:13

2 votes

1 answer

150 views

Can we find background noise for every Følner sequence in a countable amenable group?

asked May 17 at 21:43

2 votes

0 answers

115 views

Definition of the category QMet of metric spaces and quasi-isometries

asked Sep 19, 2022 at 4:09

1 vote

1 answer

125 views

How to find the point at minimal average distance of a given measure

asked Oct 10, 2022 at 16:34

1 vote

0 answers

74 views

Keller's cubing conjecture but with arbitrary cubes of side $1$

asked Nov 7, 2022 at 17:34

1 vote

0 answers

188 views

Does every amenable group $G$ admit a two-sided Folner sequence?

asked Jan 9 at 14:06

Stack Exchange Network

22 Questions

How decreasing can a bijection $f:\mathbb{N}\to\mathbb{N}$ be?

Can the nth projective space be covered by n charts?

Is there an open subset $A$ of $[0,1]^2$ with measure $>\frac{1}{100}$ that satisfies this property?

Can we make distances in a finite subset of a manifold whatever we want?

Are there $n$ points dividing a compact Riemannian manifold into equal regions?

Uncountable families of measurable sets with pairwise positive intersections

Bisector of two points in a Riemannian manifold has measure $0$

Is the union of a compact and the relatively compact components of its complementary in a manifold compact?

Stronger form of countable dense homogeneity

Non-monotileable amenable groups

Nonempty intersection of cosets of finite-index subgroups

Is every 1-Lipschitz homeomorphism $f:X\to X$ from a compact metric space to itself an isometry?

If a derivative is defined everywhere and $\pm1$ almost everywhere, is it constant?

Do sets of big returns contain sets of returns?

Growth of the constants from the Stone-Weierstrass Theorem

Maximum cardinality of separated sets in the Hamming distance

Sum of roots of unity

Can we find background noise for every Følner sequence in a countable amenable group?

Definition of the category QMet of metric spaces and quasi-isometries

How to find the point at minimal average distance of a given measure

Keller's cubing conjecture but with arbitrary cubes of side $1$

Does every amenable group $G$ admit a two-sided Folner sequence?