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Dec 26, 2020 at 15:36 answer added Sam Nead timeline score: 2
Aug 28, 2012 at 2:36 comment added Ryan Budney @Gil: yes, I'm discovering that paths can be terribly large. For example, there are triangulated homotopy 4-spheres with only 8 four-dimensional simplices in them, yet it takes no less than 80 Pachner 3-3 moves to go from one to the other! And this isn't rare.
Aug 10, 2010 at 16:32 comment added Ryan Budney One could make it into a cubical complex by only considering collections of commuting Pachner moves but I doubt this will have many rewarding properties. I suspect Walker's suggestion, below is more or less on the right track.
Aug 10, 2010 at 16:17 answer added Kevin Walker timeline score: 15
Aug 10, 2010 at 15:05 comment added Gil Kalai Very nice problem. I think the length of the Pachner path can be terribly lerribly large since deciding PL-equivalence in high dimensions is not decidable (to the best of my memory). Do you have a suggestion for the 2-cells? (not just squares, but I am not sure if we should regard every commuting moves as 2-cells.)
Aug 10, 2010 at 14:31 answer added Jim Fowler timeline score: 8
Aug 9, 2010 at 23:32 history asked Ryan Budney CC BY-SA 2.5