Rank gradient and cost of Artin groups and their relatives
We prove that the rank gradient vanishes for mapping class groups of genus bigger than 1, $Aut(F_n)$, for all $n$, $Out(F_n)$ for $n \geq 3$, and any Artin group whose underlying graph is connected. These groups have fixed price 1. We compute the rank gradient and verify that it is equal to the firs...
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| 格式: | Journal article |
| 出版: |
2012
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