User Jim Conant

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Elegant representations of graphs in R^3

added 39 characters in body

Feb 15, 2011 at 10:54

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Elegant representations of graphs in R^3

Feb 15, 2011 at 2:31

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Ordinal-indexed homology theory?

@Pete: Suppose we take that as a definition. How would we define $H_{\omega+1}(X)$?

Feb 13, 2011 at 13:58

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Nice Question

Feb 13, 2011 at 7:50

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Ordinal-indexed homology theory?

Feb 13, 2011 at 0:00

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Ordinal-indexed homology theory?

This is very close to what I am interested in!

Feb 12, 2011 at 23:17

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Ordinal-indexed homology theory?

@Martin: I agree that the usual simplex approach doesn't generalize.

Feb 12, 2011 at 22:36

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Ordinal-indexed homology theory?

Feb 12, 2011 at 21:08

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Whitehead doubles of any knots

I haven't figured out how to do matrices well.

Feb 10, 2011 at 11:52

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Whitehead doubles of any knots

Feb 10, 2011 at 11:51

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Whitehead doubles of any knots

Nice picture Ian!

Feb 10, 2011 at 11:39

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Proofs without words

I first learned this in Dan Velleman's book "How to prove it." I'm not sure if he originated it or not.

Feb 7, 2011 at 2:36

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If a result is apparently provable with AC, is actually independent of ZF?

This paper is also notable for giving a great conceptual proof of the Schröder-Bernstein theorem, as a warm-up to the main proof.

Feb 6, 2011 at 19:30

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What's the Kirby Diagram of a universal $\mathbb{R}^4$?

Gompf probably knows the answer to this.

Feb 3, 2011 at 2:52

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Autobiographer

Feb 1, 2011 at 2:50

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Contractibility of CW subcomplexes

Since $X\subset Y$ this just means that every cell of $X$ is the boundary of some other cell, which could also be in $X$.Is that what you had in mind?

Jan 28, 2011 at 15:08

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Decidability of tiling R^2

This is related to a question at Math Stacexchange: math.stackexchange.com/questions/19205/… I thought I had heard that there is a single tile such that the fact that it tiles the plane is independent of ZFC, but now I'm not so sure.

Jan 27, 2011 at 19:45

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Why is it so hard to implement Haken's Algorithm for knot theory?

@Joseph O'Rourke: do you know of a reference for the fact that unknotting is an NP problem?

Jan 25, 2011 at 20:05

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Mathematical "urban legends"

I've heard this story too.

Jan 25, 2011 at 13:03

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Does a compact semilocally simply connected geodesic space have the homotopy type of a CW complex?

I'd mark this answer correct too if I could!

Jan 12, 2011 at 19:52

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