Anomaly and Cobordism Constraints Beyond the Standard Model: Topological Force
Juven Wang
TL;DR
The paper uses Freed–Hopkins cobordism to classify invertible quantum anomalies and applies this framework to Standard Model and GUT constraints, including extensions with discrete symmetries. It shows that familiar perturbative anomalies cancel for SM and SU(5) GUT content, while a residual $\mathbb{Z}_{16}$ global anomaly associated with a ${\mathbb{Z}_{4,X}}$ discrete symmetry can remain, potentially requiring new hidden sectors. To saturate this missing anomaly, the author proposes scenarios involving a 5d invertible TQFT or a 4d noninvertible TQFT (and symmetry extensions), suggesting a novel Topological Force that mediates interactions with hidden topological sectors and can address neutrino masses and dark matter. The Ultra Unification program combines SM/GUT with topological sectors and higher-dimensional bulk dynamics, drawing on 4d–5d theories of quantum gravity and TQFTs to yield a richer, anomaly-consistent landscape with experimentally testable implications for neutrinos, dark matter, and potentially new long-range topological interactions.
Abstract
Standard lore uses local anomalies to check the kinematic consistency of gauge theories coupled to chiral fermions, e.g. Standard Models (SM). Based on a systematic cobordism classification, we examine constraints from invertible quantum anomalies (including all perturbative local and nonperturbative global anomalies) for gauge theories. We also clarify the different uses of these anomalies: including (1) anomaly cancellations of dynamical gauge fields, (2) 't Hooft anomaly matching conditions of background fields of global symmetries, and others. We apply several 4d $\mathbb{Z}_{n}$ anomaly constraints of $n=16,4,2$ classes, beyond the familiar Feynman-graph perturbative $\mathbb{Z}$ class local anomalies. As an application, for (SU(3)$\times$SU(2)$\times$U(1))/$\mathbb{Z}_q$ SM (with $q=1,2,3,6$) and SU(5) Grand Unification with 15n chiral Weyl fermions and with a discrete baryon minus lepton number $X=5({\bf B}- {\bf L})-4Y$ preserved, we discover a new hidden gapped sector previously unknown to the SM and Georgi-Glashow model. The gapped sector at low energy contains either (1) 4d non-invertible topological quantum field theory (TQFT, above the energy gap with heavy fractionalized anyon excitations from 1d particle worldline and 2d string worldsheet, inaccessible directly from Dirac or Majorana mass gap of the 16th Weyl fermions [i.e., right-handed neutrinos], but accessible via a topological quantum phase transition), or (2) 5d invertible TQFT in extra dimensions. Above a higher energy scale, the discrete $X$ becomes dynamically gauged, the entangled Universe in 4d and 5d is mediated by Topological Force. Our model potentially resolves puzzles, surmounting sterile neutrinos and dark matter, in fundamental physics.
