Timeline for A structure of the group of automorphisms of an infinite binary tree
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Feb 9, 2014 at 6:10 | vote | accept | Alex Ravsky | ||
| Feb 9, 2014 at 6:10 | comment | added | Alex Ravsky | @BenjaminSteinberg Thanks a lot. My friend said that you are a well-known specialist in this area and he is happy with your answer. | |
| Feb 4, 2014 at 19:13 | comment | added | Benjamin Steinberg | The op was not clear on this point. | |
| Feb 4, 2014 at 18:58 | comment | added | Misha | I see, I was thinking about the regular trivalent tree. | |
| Feb 4, 2014 at 15:14 | comment | added | Benjamin Steinberg | @Misha, If the OP means by binary tree the Cayley graph of the free monoid on 2-generators, then the root is the only degree 2 vertex and so must be fixed. | |
| Feb 4, 2014 at 8:52 | comment | added | Misha | One more thing: The (almost) full automorphism group $Aut_+(T)$ is an HNN extension of $Aut(T,r)$ (the group described in your answer), where $r$ is a fixed vertex of $T$ (a "root"). Here $Aut_+(T)$ is the subgroup of $Aut(T)$ of index 2 consisting of automorphisms acting without inversions. The edge subgroup here is also well-understood, it is isomorphic to the direct product $Aut(T,r)\times Aut(T,r)$. | |
| Feb 3, 2014 at 23:14 | history | edited | Benjamin Steinberg | CC BY-SA 3.0 |
link added
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| Feb 3, 2014 at 18:35 | history | answered | Benjamin Steinberg | CC BY-SA 3.0 |