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Geometry-Topology Seminar

Thursday, October 22, 2009 - 4:30pm

Louis Theran

Temple University

Location

University of Pennsylvania

DRL 4C8

A bar-and-joint framework is a planar structure made of fixed-length bars connected by universal joints with full rotational freedom. We extend this model to bar-slider frameworks in which some of the joints are constrained to move on a line, rigidly attached to the plane, much like a slider joint in mechanical engineering. A bar-slider framework is pinned if it is completely immobilized. We give a combinatorial characterization of generic pinned bar-slider frameworks. Joint work with Ileana Streinu.