Group Actions on Trees
نویسنده
چکیده
For this paper, we will define a (non-oriented) graph Γ to be a pair Γ = (V,E), where V = vert(Γ) is a set of vertices, and E = edge(Γ) ⊆ V × V/S2 is a set of unordered pairs, known as edges between them. Two vertices, v, v′ ∈ V are considered adjacent if (v, v′) ∈ E, if there is an edge between them. An oriented graph has edge set E = edge(Γ) ⊆ V × V , ordered pairs. For an edge v = (v1, v2) in an oriented graph, o(v) = v1 is the origin of v and t(v) = v2 is the terminus of v. Unless noted, all graphs in this paper are non-oriented. A group G acts on a set X if there is a map
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تاریخ انتشار 2007