Comparison of convex relaxations of quadrilinear terms

In this paper we compare four different ways to compute a convex linea r relaxation of a quadrilinear monomial on a box, analyzing their relative tightness. We computation ally compare the quality of the relaxations, and we provide a general theorem on pairwisecomparison of relaxation strength, which applies to some of our pairs of relaxations for quadrilinea r monomials. Our results can be used to configure a spatial Branch-and-Bound global optimizatio n alg rithm. We apply our results to the Molecular Distance Geometry Problem, demonstrating the usef ulness of the present study.