Grand unification and the Planck scale: An $\mathit{SO}(10)$ example of radiative symmetry breaking

Understand

Grand unification of gauge couplings and fermionic representations remains an appealing proposal to explain the seemingly coincidental structure of the Standard Model.

• However, to realise the Standard Model at low energies, the unified symmetry group has to be partially broken by a suitable scalar potential in just the right way.
• The scalar potential contains several couplings, whose values dictate the residual symmetry at a global minimum.
• Some (and possibly many) of the corresponding symmetry-breaking patterns are incompatible with the Standard Model and therefore non-admissible.