Timeline for What are the most attractive Turing undecidable problems in mathematics?
Current License: CC BY-SA 4.0
10 events
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| Feb 18, 2020 at 14:10 | history | edited | Martin Sleziak | CC BY-SA 4.0 |
http -> https (the question has been bumped anyway)
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| Feb 20, 2011 at 14:22 | comment | added | S. Carnahan♦ | @Peter: How does a group prove anything? | |
| Feb 18, 2011 at 15:36 | comment | added | Peter LeFanu Lumsdaine | @John Stillwell: but I guess we can see from this example that the group on the generators ‘S’, ‘P’, and ‘Novikov’ does not prove that P.S = S.P! | |
| May 24, 2010 at 22:34 | comment | added | John Stillwell | An interesting special case is the problem of recognizing the $n$-sphere, proved unsolvable for $n\ge 5$ by S.P. Novikov in 1962. Incidentally, S.P. Novikov is the son of P.S. Novikov, who proved the unsolvability of the word problem for groups. | |
| Jan 12, 2010 at 20:13 | history | edited | S. Carnahan♦ | CC BY-SA 2.5 |
added 64 characters in body
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| Jan 12, 2010 at 20:07 | comment | added | S. Carnahan♦ | Sorry, I was being very sloppy. | |
| Jan 12, 2010 at 20:02 | history | edited | S. Carnahan♦ | CC BY-SA 2.5 |
added 35 characters in body
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| Jan 12, 2010 at 19:16 | comment | added | Tim Perutz | There are many ways of making a precise statement. You could give a simplicial complex underlying a manifold. Or a handlebody decomposition (e.g. a Kirby diagram for a 4-manifold). Or even a finite list of polynomial equations with integer coefficients (whether this accounts for all manifolds doesn't really matter). | |
| Jan 12, 2010 at 18:53 | comment | added | Steven Gubkin | Distinguishing two manifolds given what information? How do you "give" somebody two manifolds, and ask them if they are homotopy equivalent? Do you mean if I give you an atlas for each manifold? Because I would still say this is a problem with distinguishing between representations. | |
| Jan 12, 2010 at 16:41 | history | answered | S. Carnahan♦ | CC BY-SA 2.5 |