| Title:
|
Fraïssé structures and a conjecture of Furstenberg (English) |
| Author:
|
Bartošová, Dana |
| Author:
|
Zucker, Andy |
| Language:
|
English |
| Journal:
|
Commentationes Mathematicae Universitatis Carolinae |
| ISSN:
|
0010-2628 (print) |
| ISSN:
|
1213-7243 (online) |
| Volume:
|
60 |
| Issue:
|
1 |
| Year:
|
2019 |
| Pages:
|
1-24 |
| Summary lang:
|
English |
| . |
| Category:
|
math |
| . |
| Summary:
|
We study problems concerning the Samuel compactification of the automorphism group of a countable first-order structure. A key motivating question is a problem of Furstenberg and a counter-conjecture by Pestov regarding the difference between $S(G)$, the Samuel compactification, and $E(M(G))$, the enveloping semigroup of the universal minimal flow. We resolve Furstenberg's problem for several automorphism groups and give a detailed study in the case of $G= S_\infty$, leading us to define and investigate several new types of ultrafilters on a countable set. (English) |
| Keyword:
|
Fraïssé structures |
| Keyword:
|
enveloping semigroups |
| Keyword:
|
universal minimal flow |
| MSC:
|
03E05 |
| MSC:
|
05C63 |
| MSC:
|
22F50 |
| MSC:
|
37B05 |
| idZBL:
|
Zbl 07088822 |
| idMR:
|
MR3946661 |
| DOI:
|
10.14712/1213-7243.2015.276 |
| . |
| Date available:
|
2019-05-13T07:43:12Z |
| Last updated:
|
2021-04-05 |
| Stable URL:
|
http://hdl.handle.net/10338.dmlcz/147667 |
| . |
| Reference:
|
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| . |
