User Dylan Thurston

54 votes

5 answers

2k views

Unusual symmetries of the Cayley-Menger determinant for the volume of tetrahedra

asked Jan 15, 2017 at 16:36

51 votes

3 answers

12k views

Spaces with same homotopy and homology groups that are not homotopy equivalent?

asked Jan 26, 2011 at 20:32

49 votes

2 answers

4k views

Can knot diagrams be monotonically simplified using under moves?

asked Oct 8, 2014 at 21:39

30 votes

3 answers

3k views

Examples for non-naturality of universal coefficients theorem

asked Mar 29, 2011 at 4:11

21 votes

1 answer

8k views

When is a quasi-isomorphism necessarily a homotopy equivalence?

asked Mar 24, 2011 at 5:46

21 votes

2 answers

688 views

Gluing hexagons to get a locally CAT(0) space

asked Oct 31, 2018 at 19:41

18 votes

3 answers

633 views

Classification of tangles?

asked Aug 16, 2014 at 6:15

16 votes

1 answer

750 views

Is the game Hanabi NEXPTIME-complete?

asked Oct 23, 2015 at 20:26

14 votes

3 answers

754 views

Does every CAT(0) space embed in a measurable integral of $\mathbb{R}$-trees?

asked May 5, 2015 at 1:00

14 votes

1 answer

1k views

Who proved that two homotopic embeddings of one surface in another are isotopic?

asked Sep 2, 2016 at 1:39

13 votes

2 answers

485 views

Geodesic current supported on a pencil?

asked Sep 21, 2018 at 22:47

13 votes

2 answers

1k views

Intrinsic characterization of Soergel bimodules?

asked Mar 26, 2012 at 2:34

12 votes

1 answer

327 views

What are the extremal CAT(0) metrics?

asked May 5, 2015 at 2:59

12 votes

1 answer

726 views

Injectivity of the Dehn-Nielsen-Baer map?

asked May 27, 2015 at 17:10

12 votes

0 answers

267 views

Computing the number of ways to delete vertices sequentially without disconnecting a graph

asked Apr 4, 2022 at 4:31

11 votes

1 answer

498 views

Is the center of gravity in a CAT(0) space contained in the convex hull?

asked May 7, 2015 at 9:18

10 votes

1 answer

557 views

Length inequalities in trees and CAT(0) spaces

asked Apr 17, 2014 at 23:59

10 votes

2 answers

589 views

Is the Lisca-Matic bound (aka slice-Bennequin bound) strictly stronger than the Bennequin bound?

asked Jul 17, 2018 at 16:37

10 votes

2 answers

238 views

What are the possible linking matrices of a quasi-positive link?

asked May 10, 2019 at 13:51

9 votes

3 answers

629 views

Terminology: Algebras where long strings of products are 0?

asked Apr 2, 2010 at 18:08

8 votes

0 answers

150 views

Extremal length of graphs in surfaces

asked May 11, 2015 at 15:58

8 votes

1 answer

399 views

To find a point in Teichmüller space or measured foliation, how many lengths of curves do you need?

asked Jul 11, 2019 at 4:17

7 votes

1 answer

2k views

Does midpoint-convex imply rationally convex?

asked Dec 2, 2019 at 22:15

7 votes

1 answer

315 views

Can a surface group act on a finite-valence simplicial tree?

asked Apr 13, 2016 at 17:41

6 votes

1 answer

237 views

Reference request: Can iterated torus links be mutated?

asked Aug 10, 2018 at 16:55

5 votes

1 answer

271 views

Is every triangulation of a Euclidean ball by convex tetrahedra shellable?

asked Feb 27, 2016 at 3:07

4 votes

2 answers

551 views

Fundamental domain for symmetric group $S_n$ acting on $\mathop{Gr}(k,n)$?

asked May 7, 2010 at 0:23

4 votes

2 answers

176 views

Bound areas of disks with respect to a quadratic differential

asked Dec 11, 2014 at 15:51

1 vote

0 answers

125 views

Estimating $\ell^p$ and $\ell^q$ norms on a convex cone

asked Dec 6, 2016 at 13:33

Stack Exchange Network

29 Questions

Unusual symmetries of the Cayley-Menger determinant for the volume of tetrahedra

Spaces with same homotopy and homology groups that are not homotopy equivalent?

Can knot diagrams be monotonically simplified using under moves?

Examples for non-naturality of universal coefficients theorem

When is a quasi-isomorphism necessarily a homotopy equivalence?

Gluing hexagons to get a locally CAT(0) space

Classification of tangles?

Is the game Hanabi NEXPTIME-complete?

Does every CAT(0) space embed in a measurable integral of $\mathbb{R}$-trees?

Who proved that two homotopic embeddings of one surface in another are isotopic?

Geodesic current supported on a pencil?

Intrinsic characterization of Soergel bimodules?

What are the extremal CAT(0) metrics?

Injectivity of the Dehn-Nielsen-Baer map?

Computing the number of ways to delete vertices sequentially without disconnecting a graph

Is the center of gravity in a CAT(0) space contained in the convex hull?

Length inequalities in trees and CAT(0) spaces

Is the Lisca-Matic bound (aka slice-Bennequin bound) strictly stronger than the Bennequin bound?

What are the possible linking matrices of a quasi-positive link?

Terminology: Algebras where long strings of products are 0?

Extremal length of graphs in surfaces

To find a point in Teichmüller space or measured foliation, how many lengths of curves do you need?

Does midpoint-convex imply rationally convex?

Can a surface group act on a finite-valence simplicial tree?

Reference request: Can iterated torus links be mutated?

Is every triangulation of a Euclidean ball by convex tetrahedra shellable?

Fundamental domain for symmetric group $S_n$ acting on $\mathop{Gr}(k,n)$?

Bound areas of disks with respect to a quadratic differential

Estimating $\ell^p$ and $\ell^q$ norms on a convex cone