Foldings, Graphs of Groups and the Membership Problem
نویسندگان
چکیده
We introduce a combinatorial version of Stallings-Bestvina-Feighn-Dunwoody folding sequences. We then show how they are useful in analyzing the solvability of the uniform subgroup membership problem for fundamental groups of graphs of groups. Applications include coherent right-angled Artin groups and coherent solvable groups.
منابع مشابه
The Membership Problem for Switching Classes with Skew Gains
Gain graphs are graphs in which each edge has a gain (a label from a group so that reversing the direction of an edge inverses the gain). In this paper we take a generalized view of gain graphs in which the label of an edge is related to the label of the reverse edge by an involution, i.e., an anti-automorphism of order at most two. Switching classes are equivalence classes of gain graphs under...
متن کاملFUZZY GOAL PROGRAMMING TECHNIQUE TO SOLVE MULTIOBJECTIVE TRANSPORTATION PROBLEMS WITH SOME NON-LINEAR MEMBERSHIP FUNCTIONS
The linear multiobjective transportation problem is a special type of vector minimum problem in which constraints are all equality type and the objectives are conicting in nature. This paper presents an application of fuzzy goal programming to the linear multiobjective transportation problem. In this paper, we use a special type of nonlinear (hyperbolic and exponential) membership functions to ...
متن کاملStrength of strongest dominating sets in fuzzy graphs
A set S of vertices in a graph G=(V,E) is a dominating set ofG if every vertex of V-S is adjacent to some vertex of S.For an integer k≥1, a set S of vertices is a k-step dominating set if any vertex of $G$ is at distance k from somevertex of S. In this paper, using membership values of vertices and edges in fuzzy graphs, we introduce the concepts of strength of strongestdominating set as well a...
متن کامل1 M ay 2 00 9 The fully residually F quotients of F ∗ 〈 x , y 〉
We describe the fully residually F groups; or limit groups relative to F ; that arise as the coordinate groups of irreducible systems of equations in two variables over a free group F that have coefficients in F. We use the structure theory of f.g. fully residually free groups and Bass-Serre theory. In particular we use foldings sequences for subgroups of fundamental groups of graphs of groups.
متن کاملAn algorithm for determining common weights by concept of membership function
Data envelopment analysis (DEA) is a method to evaluate the relative efficiency of decision making units (DMUs). In this method, the issue has always been to determine a set of weights for each DMU which often caused many problems. Since the DEA models also have the multi-objective linear programming (MOLP) problems nature, a rational relationship can be established between MOLP and DEA problem...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- IJAC
دوره 15 شماره
صفحات -
تاریخ انتشار 2005