In 2020, physicist Juven Wang introduced a concept known as "ultra unification". It combines the Standard Model and grand unification, particularly for the models with 15 Weyl fermions per generation, without the necessity of right-handed sterile neutrinos, by adding new gapped topological phase sectors or new gapless interacting conformal sectors consistent with the nonperturbative global anomaly cancellation and cobordism constraints (especially from the mixed gauge-gravitational anomaly, such as a Z / 16 Z class anomaly, associated with the baryon minus lepton number B − L and the electroweak hypercharge Y).