We consider three parametric relaxations of the (0, 1)-quadratic progr
amming problem. These relaxations are to: quadratic maximization over
simple box constraints, quadratic maximization over the sphere, and th
e maximum eigenvalue of a bordered matrix. When minimized over the par
ameter, each of the relaxations provides an upper bound on the origina
l discrete problem. Moreover, these bounds are efficiently computable.
Our main result is that, surprisingly, all three bounds are equal.