Constraint theory, vector percolation and glass formation.

We connect the Phillips constraint theory of glass formation to numerical simulations of vector percolation with nearest neighbor central forces. Feng and Sen have shown that the addition of bond-bending forces shifts the vector percolation threshold to the scalar value in two dimensions. Using constraint theory we show that in the mean-field approximation for d > 2 the correct non- central vector threshold lies between the scalar and central vector thresholds. For a fully equilibrated statically disordered network mean-field theory may be almost exact.