Ryan Budney's user avatar
Ryan Budney's user avatar
Ryan Budney's user avatar
Ryan Budney
  • Member for 14 years, 4 months
  • Last seen this week
81 votes
7 answers
7k views

Computational complexity of computing homotopy groups of spheres

61 votes
10 answers
10k views

Teaching proofs in the era of Google

59 votes
9 answers
7k views

Has anyone thought about creating a formal proof wiki with verifier?

58 votes
6 answers
7k views

Torsion in homology or fundamental group of subsets of Euclidean 3-space

31 votes
3 answers
2k views

A Pachner complex for triangulated manifolds

24 votes
3 answers
2k views

How expensive is knowledge? Knots, Links, 3 and 4-manifold algorithms. [closed]

24 votes
0 answers
1k views

Monoid structure of oriented manifolds with connect sum

24 votes
3 answers
2k views

Persistent homology of Gaussian fields in Euclidean space

24 votes
4 answers
4k views

Curriculum reform success stories at an "average" research university

23 votes
2 answers
4k views

Isotopy extension theorems

23 votes
2 answers
791 views

Which homotopy classes $S^3 \to S^2$ lift to embeddings $S^3 \to S^2 \times D^3$?

22 votes
1 answer
1k views

Word problem for fundamental group of submanifolds of the 4-sphere

22 votes
3 answers
1k views

"Largest" finite-dimensional Lie subgroups of Diff(S^n), are they known?

20 votes
9 answers
3k views

Hironaka desingularisation theorem -- new proofs in literature?

16 votes
5 answers
4k views

can you fool SnapPea?

16 votes
3 answers
1k views

Looking for "large knot" examples

14 votes
0 answers
438 views

Structure of Gordian graph of knots

13 votes
1 answer
1k views

Mapping class groups of small Seifert-fibred 3-manifolds

13 votes
2 answers
1k views

Explicit embeddings of Cappell-Shaneson knots

12 votes
3 answers
1k views

Knot theory question: bridge number vs. min generators of fundamental group of complement

12 votes
1 answer
499 views

Lower bounds on dimensions of faithful representations of braid groups

12 votes
1 answer
518 views

4-manifolds in the 4-sphere such that it, *and* its complement have unsolvable word problem

12 votes
2 answers
536 views

Curvature flows for PL closed curves in the plane?

11 votes
1 answer
572 views

Revisiting Gordon-Luecke theorem

11 votes
2 answers
523 views

Simplicial replacements in smoothing theory

11 votes
2 answers
2k views

slice-ribbon for links (surely it's wrong)

11 votes
6 answers
1k views

Computing the structure of the group completion of an abelian monoid, how hard can it be?

11 votes
2 answers
581 views

Some mid-sized ¿hyperbolic? manifolds and SnapPea

11 votes
0 answers
495 views

The spheres operad

10 votes
2 answers
576 views

Embedding the product of three circles in the 4-sphere.