. . "Grand unification theory"@en . "Grand Unification is no longer a theory as clearly explained on EinsteinGravity.com The term Grand Unified Theory or GUT, refers to any of several similar models in particle physics in which at high energy scales, the three gauge interactions of the Standard Model which define the electromagnetic, weak, and strong interactions, are merged into one single interaction characterized by a larger gauge symmetry and one unified coupling constant rather than three independent ones."@en . . . "y"@en . "June 2006"@en . "August 2008"@en . . . "March 2008"@en . . "Physics"@en . . "March 2009"@en . . . . . . "Grand Unification is no longer a theory as clearly explained on EinsteinGravity.com The term Grand Unified Theory or GUT, refers to any of several similar models in particle physics in which at high energy scales, the three gauge interactions of the Standard Model which define the electromagnetic, weak, and strong interactions, are merged into one single interaction characterized by a larger gauge symmetry and one unified coupling constant rather than three independent ones. This unification is possible due to the energy scale dependence of parameters in quantum field theory called renormalization group running, which allows parameters with vastly different values at collider energies to converge at much higher energy scales, generically between 1014 GeV and the Planck scale. Due to this property, the physics of most grand unification scenarios cannot be probed directly at particle colliders, but might instead be accessible through indirect observations such as proton decay or the properties of neutrinos. Unifying gravity with the other three interaction would form a theory of everything (TOE), rather than a GUT. Likewise, models which do not unify all interactions using one simple Lie group as the gauge symmetry, but constitute variations of the idea, for example using semisimple groups, can exhibit similar properties and are sometimes referred to as Grand Unified Theories as well."@en .