The idea was described by Yoichiro Nambu[citation needed] and subsequently developed by Miransky, Tanabashi, and Yamawaki (1989)[1][2] and William A. Bardeen, Christopher T. Hill, and Manfred Lindner (1990),[3] who connected the theory to the renormalization group, and improved its predictions.
At this high scale a bound-state Higgs forms, and in the "infrared", the coupling relaxes to its measured value of order unity by the renormalization group.
However, extended versions of the theory, introducing more particles, can be consistent with the observed top quark and Higgs boson masses.
To be "natural", that is, without excessive fine-tuning (i.e. to stabilize the Higgs mass from large radiative corrections), the hypothesis requires new physics at a relatively low energy scale.
The predicted top quark mass would come into improved agreement with the fixed point if there are many additional Higgs scalars beyond the standard model.