Tarski numbers of group actions
Event details
| Date | 07.05.2015 |
| Hour | 13:00 › 14:00 |
| Speaker | Gili Golan (Bar-Ilan) |
| Location | |
| Category | Conferences - Seminars |
The Tarski number of a group action is the minimal number of pieces in a paradoxical decomposition of it. We give a solution to the problem of describing the set of Tarski numbers of group actions. Namely, for any k ≥ 4 we construct a faithful transitive action of a free group with Tarski number k. We also construct an action of a group G on a set X with Tarski number 6 such that Tarski numbers of restrictions of this action to finite index subgroups of G are arbitrarily large.
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