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 [6] [7] [8] [9] (especially from the mixed gauge-gravitational anomaly, such as a Z/16Z class anomaly, associated with the baryon minus lepton number B−L and the electroweak hypercharge Y).
[10] Gapped topological phase sectors are constructed via the symmetry extension (in contrast to the symmetry breaking in the Standard Model's Anderson-Higgs mechanism), whose low energy contains unitary Lorentz invariant Schwarz type [11] topological quantum field theories (TQFTs such as Chern-Simons theory [12]), such as 4-dimensional noninvertible, 5-dimensional noninvertible, or 5-dimensional invertible entangled gapped phase TQFTs.
Alternatively, ultra unification suggests there could also be right-handed sterile neutrinos, gapless unparticle physics, or some combination of more general interacting conformal field theories (CFTs), to together cancel the mixed gauge-gravitational anomaly.
This includes gapped extended objects such as 1-dimensional line and 2-dimensional surface operators or conformal defects, whose open ends carry deconfined fractionalized particle or anyonic string excitations.
Understanding and characterizing these gapped extended objects requires mathematical concepts such as cohomology, cobordism, or category into particle physics.