Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 2051

Topology of cell complexes and manifolds, classification of manifolds (e.g. smoothing, surgery), low dimensional topology (e.g. knot theory, invariants of 4-manifolds), embedding theory, combinatorial and PL topology, geometric group theory, infinite dimensional topology (e.g. Hilbert cube manifolds, theory of retracts).

24 votes
3 answers
3k views

Elevator pitch for the Virtual Fibering Theorem

There has been a great deal of excitement among topologists about the proof of the Virtual Haken Theorem, and in fact of the Virtual Fibering Theorem (for closed hyperbolic 3-manifolds, but I'm guess …
3 votes
1 answer
174 views

Tait conjectures for alternating w-links

The Tait Conjectures are useful in knot tabulation. For alternating knots and links, two of them state: Any reduced diagram of an alternating link has the fewest possible crossings. Any two reduced …
14 votes
Accepted

Knot diagrams, sets of moves and equivalence relations

Very much so. There are a number of small industries centred around studying equivalence classes of knot diagrams generated by a set of moves. The study of claspers. For example, $C_k$-moves are a sp …
The Amplitwist's user avatar
30 votes
2 answers
3k views

The difference between a handle decomposition and a CW decomposition

Let $M$ be a compact finite-dimensional smooth manifold. I have a question about the relationship between the statements that a Morse function induces a handle decomposition for $M$, and that it induc …
13 votes

Is the HOMFLY Polynomial the best knot invariant?

What about the coloured HOMFLYPT? It's clearly stronger than the HOMFLYPT. Whether it is a complete knot invariant is (I believe) open. Mutation preserves the HOMFLYPT polynomial. The 2-variable HOMFL …
Glorfindel's user avatar
  • 2,821
2 votes

Is Murasugi's conjecture still open?

See also this paper by Jong which reproves the Ozsvath-Szabo result combinatorially, using Stoimenow's generators for knots of canonical genus 2. The interesting question which is lurking in the backg …
Glorfindel's user avatar
  • 2,821
5 votes

Kirby calculus and local moves

I think that the answer to your question is yes EDIT: if you allow local to mean "local within a thickened surface" or allow local moves between tangles whose strands may not be part of the surgery li …
Glorfindel's user avatar
  • 2,821
35 votes
4 answers
4k views

Extending a diffeomorphism of the sphere $S^2$ to the ball $D^3$

A fundamental result in three-dimensional smooth topology, which in computer jargon we might refer to as "a primitive", is the statement that any ($C^\infty$) diffeomorphism of the two-sphere $S^2$ ex …
21 votes
1 answer
2k views

How are the Conway polynomial and the Alexander polynomial different?

Background story: I have just come out from a talk by Misha Polyak on generalizations of an arrow-diagram formula for coefficients of the Conway polynomial by Chmutov, Khoury, and Rossi. In it, he des …
82 votes
12 answers
15k views

Compelling evidence that two basepoints are better than one

This question is inspired by an answer of Tim Porter. Ronnie Brown pioneered a framework for homotopy theory in which one may consider multiple basepoints. These ideas are accessibly presented in his …
8 votes

Kirby calculus and local moves

If you didn't like my first answer, here's a different one; again, slightly changing the question. This answer is better suited to the way the Kirby theorem is used in quantum topology. Consider the s …
Martin Sleziak's user avatar
8 votes
2 answers
858 views

Are there any very hard unlinks?

This question is closely related to a question of Gowers: Are there any very hard unknots? . I'm thinking about how to create interesting knots from small numbers of local moves on unlinks. The "stand …
23 votes
Accepted

Proofs of Kirby's theorem

There is Bob Craggs' 1974 proof, which was never published. It relies on Wall's result, that any two 2-handle cobordisms between S^3 and itself are stably homeomorphic if the associated bilinear form …
David Roberts's user avatar
  • 35.5k
9 votes
2 answers
669 views

Does every knot contain all four vertices of an isosceles trapezoid?

I ask this question with some trepidation, because it may be trivial and/or of entirely recreational interest. Erika Pannwitz proved in 1933 that every non-trivial knot contains a quadrisecant (four p …
8 votes

What are some of the big open problems in 3-manifold theory?

The Virtually Fibred Conjecture, and related problems. For a weaker definition of 3-manifold topology, I think the Andrews-Curtis conjecture is a key problem. Also, anything which relates to the class …
Martin Sleziak's user avatar

1
2 3 4 5
15 30 50 per page