Abstract
Let G = (V, E) be a graph and \({u, v \in V}\) be two distinct vertices. We give a necessary and sufficient condition for the existence of an infinitesimally rigid two-dimensional bar-and-joint framework (G, p), in which the positions of u and v coincide. We also determine the rank function of the corresponding modified generic rigidity matroid on ground-set E. The results lead to efficient algorithms for testing whether a graph has such a coincident realization with respect to a designated vertex pair and, more generally, for computing the rank of G in the matroid.
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Fekete, Z., Jordán, T. & Kaszanitzky, V.E. Rigid Two-Dimensional Frameworks with Two Coincident Points. Graphs and Combinatorics 31, 585–599 (2015). https://doi.org/10.1007/s00373-013-1390-0
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DOI: https://doi.org/10.1007/s00373-013-1390-0