Henno Brandsma's user avatar
Henno Brandsma's user avatar
Henno Brandsma's user avatar
Henno Brandsma
  • Member for 14 years, 4 months
  • Last seen more than 2 years ago
72 votes

Is $\mathbb R^3$ the square of some topological space?

33 votes

Quick proofs of hard theorems

21 votes

What is your favorite proof of Tychonoff's Theorem?

20 votes

Locally compact Hausdorff space that is not normal

19 votes

Are nets and filters useful in geometry and topology?

19 votes

Can Cantor set be the zero set of a continuous function?

17 votes

How many orders of infinity are there?

16 votes

Discrete subspaces of Hausdorff spaces

15 votes

What are interesting families of subsets of a given set?

13 votes

What are your favorite instructional counterexamples?

12 votes

Which are the rigid suborders of the real line?

12 votes

What are some reasonable-sounding statements that are independent of ZFC?

11 votes

What are some results in mathematics that have snappy proofs using model theory?

11 votes

Writing papers in pre-LaTeX era?

10 votes
Accepted

CCC + collectionwise normality => paracompact?

9 votes
Accepted

Are countable unions of metrizable spaces metrizable too?

9 votes
Accepted

Proper continuous image of metrizable space

8 votes
Accepted

Must a linearly ordered, separable space be metrizable?

8 votes

Subset of the plane that intersects every line exactly twice

8 votes
Accepted

Which compact metrizable spaces have continuous choice functions for non-empty closed sets?

7 votes
Accepted

Is ω1 × βN normal?

7 votes

Fundamental Examples

7 votes
Accepted

Homeomorphic open sets and homogeneity

6 votes

A question on metrizable space

6 votes

Elementary+Short+Useful

6 votes

The core question of topology

6 votes
Accepted

Lebesgue dimension of images

5 votes

Naturally occuring groups with cardinality greater than the reals.

5 votes

Books you would like to see translated into English

5 votes

The Root of a Line