Abstract
A connected, locally finite graph Γ is a Cayley-Abels graph for a totally disconnected, locally compact group G if G acts vertex-transitively on Γ with compact, open vertex stabilizers. Define the minimal degree of G as the minimal degree of a Cayley-Abels graph of G. We relate the minimal degree in various ways to the modular function, the scale function and the structure of compact open subgroups. As an application, we prove that if Tddenotes the d-regular tree, then the minimal degree of Aut(Td) is d for all d ≥ 2.
Original language | English |
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Pages (from-to) | 145-177 |
Number of pages | 33 |
Journal | Journal of the Australian Mathematical Society |
Volume | 114 |
Issue number | 2 |
DOIs | |
State | Published - 13 Apr 2023 |
Externally published | Yes |
Keywords
- Cayley-Abels graphs
- groups acting on trees
- modular function
- scale function
- totally disconnected locally compact groups
ASJC Scopus subject areas
- General Mathematics