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Nov 28, 2019 at 7:49 comment added YCor @user334639 Oh, indeed my comment I forgot to write what I meant... the claim is that the group $G$ (which is a locally compact topological group under the pointwise convergence topology) is unimodular. And it also works for the closure in $G$ of every generously vertex-transitive subgroup.
Nov 28, 2019 at 1:12 comment added user334639 @YCor Thanks for the comment and for editing the question! I'm not quite sure what you are trying to prove in your comment. Are you justifying that GVT implies unimodular?
Nov 26, 2019 at 9:49 history edited YCor
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Nov 26, 2019 at 9:20 comment added YCor Remark: if $X$ is such a graph and $G$ is its automorphism group (with a fixed left Haar measure), any two vertex stabilizers are conjugate by some element $g$ whose square fixes a vertex. In particular, $g$ belongs to a compact subgroup and hence $\Delta(g)=1$; thus all vertex stabilizers have the same Haar measure. Thus $G$ is unimodular. (While there exist many vertex-transitive finite degree connected graph with non-unimodular automorphism group.)
Nov 26, 2019 at 8:10 history edited YCor CC BY-SA 4.0
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Nov 26, 2019 at 8:06 history edited Martin Sleziak CC BY-SA 4.0
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Jul 31, 2015 at 21:31 vote accept user334639
Jul 31, 2015 at 17:43 answer added Adam P. Goucher timeline score: 5
Jul 31, 2015 at 14:11 history edited user334639 CC BY-SA 3.0
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Jul 31, 2015 at 13:52 history edited user334639 CC BY-SA 3.0
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Jul 31, 2015 at 4:50 answer added Igor Rivin timeline score: 3
Jul 31, 2015 at 3:33 comment added user334639 Thank you all for feedback. Question has been edited to remove some of these obscurities.
Jul 31, 2015 at 3:31 history edited user334639 CC BY-SA 3.0
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Jul 30, 2015 at 9:59 comment added nvcleemp I think the OP means "For the last fact..."
Jul 30, 2015 at 1:39 comment added Gerry Myerson "For the last claim...." But no claims are made. What do you mean?
Jul 29, 2015 at 22:27 comment added Chris Godsil A permutation group $G$ on a set $V$ is generously transitive if, for each pair of points from $F$, there is an element of $G$ that swaps them. The literature I am aware of focusses on the finite case.
Jul 29, 2015 at 18:39 comment added Dave Witte Morris Perhaps you want to assume the graph has finite valence? Otherwise, the first question is answered by the complement of @ErikRijcken's example.
Jul 29, 2015 at 14:05 history edited user334639 CC BY-SA 3.0
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Jul 29, 2015 at 13:49 comment added Erik Rijcken Do you assume your graph to be connected? Otherwise, to answer your first question, you could take infinitely many copies of the Petersen graph.
Jul 29, 2015 at 13:03 review First posts
Jul 29, 2015 at 14:04
Jul 29, 2015 at 12:59 history asked user334639 CC BY-SA 3.0