As of May 31, 2023, we have updated our Code of Conduct.
Michał Kukieła's user avatar
Michał Kukieła's user avatar
Michał Kukieła's user avatar
Michał Kukieła
  • Member for 13 years, 5 months
  • Last seen more than 1 year ago
20 votes

What are your favorite instructional counterexamples?

12 votes

Is the fixed point property for posets preserved by products?

10 votes

Interesting examples of vacuous / void entities

10 votes

The half-life of a theorem, or Arnold's principle at work

9 votes

Great mathematicians born 1850-1920 (ET Bell's book ≲ x ≲ Fields Medalists)

9 votes

Continuous bijections vs. Homeomorphisms

7 votes

In model theory, does compactness easily imply completeness?

7 votes

Why the search for ever larger primes?

6 votes

fixed simplicial complex under group action

5 votes

Cops and drunken robbers

5 votes

Example of collapsible complex which collapses to a non-collapsible complex

4 votes

Are there two non-homotopy equivalent spaces with equal homotopy groups?

4 votes

Banach and Knaster-Tarski fixed point theorems -- are they related?

4 votes

Non-homeomorphic spaces that have continuous bijections between them

4 votes

Fixed point theorems

4 votes
Accepted

Fixed-point-free group action on a finite, contractible, 3-dimensional simplicial complex

3 votes

Examples of graph properties characterized by forbidden (not necessarily induced) subgraphs

2 votes

Video lectures of mathematics courses available online for free

2 votes

Elementary+Short+Useful

2 votes

Computing homology of very large posets

2 votes

Algorithm to find an acyclic matching on a poset

2 votes

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

1 vote
Accepted

Maximal number of antichains of a connected poset

1 vote

Topological properties for which bijectively related imply homeomorphism

1 vote

Knaster Tarski theorem, example needed

1 vote

A book in topology

1 vote

CW complex with generalized cells

0 votes

Fixed point for a self-mapping on subset of C[0,1]

0 votes

Which great mathematicians had great political commitments?