Global rigidity of unit ball graphs
A d-dimensional bar-and-joint framework (G,p), where G is a graph and p maps the vertices of G to points in Rd, is said to be globally rigid if every d-dimensional framework (G,q) with the same graph and same edge lengths is congruent to (G,p). Global rigidity of frameworks and graphs is a well-studied area of rigidity theory with a number of applications, including the localization problem of sensor networks. Motivated by this application we consider the new notion of unit ball global rigidity, which can be defined similarly, except that (G,p) as well as (G,q) are required to be unit ball frameworks in the above definition. In a unit ball framework two vertices are adjacent if and only if their distance is less than a fixed constant (which corresponds to the sensing radius in a sensor network). We initiate a theoretical analysis of this version of global rigidity and prove several structural results. This is joint work with Dániel Garamvölgyi.