  A bar framework in R^r, denoted by G(p), is a simple connected graph G whose
vertices are points p^1,...,p^n in R^r that affinely span R^r, and whose edges
are line segments between pairs of these points. In this paper, we use stress
matrices to characterize the universal and global rigidities of chordal bar
frameworks in general position in R^r, i.e., bar frameworks where graph G is
chordal and the points p^1,...,p^n are in general position in R^r. We also
prove that if a chordal bar framework in R^r admits a stress matrix of rank
n-r-1 with generic rank profile, then it admits a positive semidefinite stress
matrix of rank n-r-1.
