منابع مشابه
Context-Free Groups and their Structure Trees
Let Γ be a connected, locally finite graph of finite tree width and G be a group acting on it with finitely many orbits and finite node stabilizers. We provide an elementary and direct construction of a tree T on which G acts with finitely many orbits and finite vertex stabilizers. Moreover, the tree is defined directly in terms of the structure tree of optimally nested cuts of Γ. Once the tree...
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If γ is an edge-path of length 0, consisting of the vertex v , then we set α(γ) = ω(γ) = v . If γ = (e1, . . . , en) is an edge-path of positive length we wet α(γ) = α(e1) and ω(γ) = ω(en). When α(γ) = v1 and ω(γ) = v2 then we say that γ joins v1 to v2. If γ = (e1, . . . , en) is an edge-path which joins v to w then (ēn, . . . , ē1) is an edge-path which joins w to v , and it will be denoted γ̄....
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This paper is the first of a sequence of three papers, where the concept of an Rtree dual to (the lift to the universal covering of) a measured geodesic lamination L in a hyperbolic surface S is generalized to arbitrary R-trees provided with a (very small) action of the free group FN of finite rank N ≥ 2 by isometries. In [CHL-II] to any such R-tree T a dual algebraic lamination L(T ) is associ...
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The exponent of periodicity is an important factor in estimates of complexity of word-unification algorithms. We prove that the exponent of periodicity of a minimal solution of a word equation is at most 2, where n is the length of the equation. Since the best known lower bound is 2 our upper bound is almost optimal and exponentially better than the original bound (6n) 2n4 + 2. Thus our result ...
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The self-similar structure of the attracting subshift of a primitive substitution is carried over to the limit set of the repelling tree in the boundary of Outer Space of the corresponding irreducible outer automorphism of a free group. Thus, this repelling tree is self-similar (in the sense of graph directed constructions). Its Hausdorff dimension is computed. This reveals the fractal nature o...
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ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 1990
ISSN: 0022-4049
DOI: 10.1016/0022-4049(90)90136-6