User Dan Rust - Mathematics Stack Exchange

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Dan Rust

Member for 11 years, 1 month
Last seen this week

sites.google.com/view/danrust
Milton Keynes, UK

756 Answers

Score Activity Newest

53 votes

Accepted

An intuitive idea about fundamental group of $\mathbb{RP}^2$

answered May 6, 2013 at 17:44

44 votes

Accepted

Unit sphere in $\mathbb{R}^\infty$ is contractible?

answered Jan 19, 2013 at 21:19

44 votes

Accepted

What is the mathematical significance of Penrose tiles?

answered May 6, 2014 at 20:27

41 votes

Does $G\cong G/H$ imply that $H$ is trivial?

answered Sep 11, 2013 at 21:00

41 votes

What are the most overpowered theorems in mathematics?

answered Nov 7, 2013 at 13:51

34 votes

Accepted

Example of a non-hausdorff space

answered Dec 17, 2013 at 16:08

22 votes

Visually deceptive "proofs" which are mathematically wrong

answered Apr 15, 2014 at 23:03

22 votes

Are there any open mathematical puzzles?

answered Oct 21, 2013 at 1:14

22 votes

Are these 2 graphs isomorphic?

answered May 16, 2013 at 12:35

21 votes

Simply connected manifolds are orientable

answered May 8, 2014 at 14:53

20 votes

What is the oldest open problem in geometry?

answered Aug 12, 2014 at 20:35

20 votes

List of interesting math podcasts?

answered Mar 12, 2013 at 20:58

20 votes

Proving that $\mathbb{F}^\infty$ is infinite-dimensional.

answered Sep 5, 2013 at 10:19

17 votes

Accepted

Topological Meaning of semi-direct product

answered Jan 13, 2013 at 1:01

17 votes

What is $\pi_{31}(S^2)$?

answered May 15, 2013 at 11:27

15 votes

Why should Rubik's cube get attention from mathematicians?

answered Feb 24, 2013 at 17:15

15 votes

Homology group of Real projective plane

answered Apr 25, 2014 at 14:11

14 votes

Accepted

Does every irrational number contain arbitrarily long sequences of some digit?

answered Sep 5, 2015 at 0:00

13 votes

Area of intersection between two circles

answered May 26, 2013 at 13:52

12 votes

Accepted

Pi might contain all finite sets, can it also contain infinite sets?

answered Sep 11, 2013 at 1:32

12 votes

Image of Intersection of sects not equal to intersection of images of sets

answered Sep 3, 2013 at 2:14

11 votes

$\mathbb{S}^2$ as a fibre bundle

answered Jul 3, 2013 at 11:41

11 votes

Accepted

Fundamental group of the Klein bottle, using action of a group?

answered Feb 24, 2013 at 22:50

11 votes

Higher Homotopy Group of a Product of Spaces

answered May 4, 2014 at 14:22

11 votes

What does it mean when a bound is sharp?

answered Oct 26, 2016 at 10:05

10 votes

Accepted

$H_2(M)$ is free abelian for any simply connected $4$-manifold

answered Nov 27, 2014 at 21:40

10 votes

$\mathbb{Z}$ and $\mathbb{Q}$ are not homeomorphic

answered Mar 31, 2013 at 14:22

10 votes

Accepted

What is the difference between differential topology and calculus on manifolds?

answered Aug 12, 2013 at 10:44

10 votes

Accepted

Complement of a Topology

answered Jun 8, 2013 at 13:28

10 votes

How to show that a disjoint sum of metric spaces is metrizable?

answered Aug 20, 2013 at 13:45

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