Timeline for Non-amenable groups with arbitrarily large Tarski number?
Current License: CC BY-SA 4.0
19 events
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| S Jun 5, 2021 at 17:19 | history | suggested | Jannik Pitt | CC BY-SA 4.0 |
change cited papers to italic to improve readability
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| Jun 5, 2021 at 11:14 | review | Suggested edits | |||
| S Jun 5, 2021 at 17:19 | |||||
| Jun 15, 2020 at 7:27 | history | edited | CommunityBot |
Commonmark migration
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| Oct 6, 2018 at 16:24 | history | edited | user6976 | CC BY-SA 4.0 |
a misprint fixed
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| Nov 7, 2017 at 15:59 | comment | added | LSpice | Clickable link: Ershov, Golan, and Sapir - The Tarski numbers of groups (MSN). | |
| Jul 5, 2017 at 0:14 | comment | added | user6976 | @DanSălăjan: See MR3391070 Ershov, Mikhail; Golan, Gili; Sapir, Mark The Tarski numbers of groups. Adv. Math. 284 (2015), 21–53. | |
| Jul 31, 2013 at 12:26 | history | edited | user6976 | CC BY-SA 3.0 |
added 79 characters in body
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| Jul 28, 2013 at 14:56 | history | edited | user6976 | CC BY-SA 3.0 |
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| Jul 26, 2013 at 2:54 | comment | added | Narutaka OZAWA | This is great, indeed. I never imagined it could be solved so quickly! | |
| Jul 26, 2013 at 2:51 | vote | accept | Narutaka OZAWA | ||
| Jul 25, 2013 at 19:30 | history | edited | user6976 | CC BY-SA 3.0 |
added 379 characters in body; deleted 8 characters in body; added 1 characters in body
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| Jul 25, 2013 at 13:12 | comment | added | Dan Sălăjan | @Mark: Great. It would be very nice if you could write some more details (if you have time, of course), this fact is a rather big improvement in the Von Neumann-Day question... | |
| Jul 25, 2013 at 11:52 | comment | added | user6976 | @Dan: I do not think it is a problem, you can always make $t$ smaller by adding relations (and preserving (T)). | |
| Jul 25, 2013 at 11:29 | comment | added | Dan Sălăjan | Amazing! I do not understand yet the proofs in Ershov, so I apologize for the following mechanical question: in Theorem 12.1 the quantity $1-H_t+H_R(t)$ is negative for $t=2/d$ while in the proof of 3.3 it starts with a group with $t$ between $1/d$ and $1/(d-1)$? Is that ok?(t= tau) | |
| Jul 25, 2013 at 11:28 | comment | added | user6976 | The reason it was open was that when the problem was formulated by Ceccherini-Silberstein, Grigorchuk, and de la Harpe, GS groups with property (T) (or even with property ($\tau$)) were not known. In fact many people believed that such groups do not exist. Also I am not sure that they considered GS groups. After Ershov found a GS group with property (T), nobody noticed that it solves the problem - till now. | |
| Jul 25, 2013 at 10:56 | comment | added | HJRW | That seems eminently deserving of a +1! | |
| Jul 25, 2013 at 10:43 | comment | added | user6976 | That is correct. | |
| Jul 25, 2013 at 10:41 | comment | added | HJRW | So the problem was open when you started writing the answer, and solved by the time you'd finished!? | |
| Jul 25, 2013 at 10:33 | history | answered | user6976 | CC BY-SA 3.0 |