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Dec 5, 2023 at 3:19 comment added Ryan Budney The Wikipedia page is due to me. I wrote down the definition mostly based on conversations with Danny Ruberman. If you think I should change the emphasis, just let me know.
Jan 6, 2021 at 22:30 comment added user160180 Dear Professor Ruberman, slice disks corresponding to slice knots may be different. I don't understand why all contractible manifolds built in this way have a single 0-, 1-, and 2-handle except the case the slice knot is the unknot.
Dec 29, 2020 at 15:58 comment added Danny Ruberman 2. The precise meaning of the term "Mazur manifold" is not universally agreed on. I think most people say this means there's a single 0/1/2 handle, some mean the specific example in Mazur's paper, and Wikipedia claims that some say that any contractible manifold is a Mazur manifold. (I've never heard this, though.) As a point of history, we should probably say Mazur-Poenaru manifolds.
Dec 29, 2020 at 15:55 comment added Danny Ruberman 1. You can use any slice disk; you have to take care with the curve you use as I described. I'd guess that most of the 4-manifolds will require > 1 1-handle, and possibly some 3-handles if your disk is not ribbon.
Dec 29, 2020 at 11:19 comment added user160180 I checked the algebraic details so that everything holds. I have two more questions: 1. Why we can replace the slice disk freely? 2. These contractible manifolds are all built from one 0-handle, one 1-handle and one 2-handle, i.e., all of them are Mazur?
Dec 27, 2020 at 19:51 comment added Danny Ruberman There are two knots in question. The slice knot K and the other curve $\gamma$. If you do 0-framed surgery on K, and $\gamma$ normally generates the fundamental group, then you get a homology sphere no matter what the framing is on $\gamma$. As you say, the boundary of a contractible manifold must be a homology sphere.
Dec 27, 2020 at 11:22 comment added user160180 Attaching $2$-handle corresponds to doing integral surgery. Let $Y$ be the $3$-manifold which is obtained by $0$-surgery on a slice knot. We also need to assume that the resulting $3$-manifold which is obtained by surgery on a knot in $Y$ is a homology sphere, right? Or it is a consequence of having contractible $4$-manifold?
Dec 26, 2020 at 22:12 vote accept CommunityBot
Dec 26, 2020 at 21:49 comment added Danny Ruberman Yes, providing that the condition I mentioned is satisfied: the homotopy class of $\gamma$ must normally generate the fundamental group of the 0-surgered manifold.
Dec 26, 2020 at 21:35 comment added user160180 Thus, if $\gamma$ is a knot in the $3$-manifold obtained by $0$-surgery on a slice knot, and if we attach $2$-handle along $\gamma$, we produce a contractible manifold, right?
Dec 25, 2020 at 14:10 history edited Danny Ruberman CC BY-SA 4.0
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Dec 24, 2020 at 23:29 history answered Danny Ruberman CC BY-SA 4.0