A Three-Way Constraint Taxonomy of the Fundamental Interactions

We propose a three-way classification of the fundamental interactions according to how an underlying structure permits, protects, or gaps the propagation of disturbances: unconstrained propagation (gravity and electromagnetism, with inverse-square attenuation as the geometric baseline), topological protection (the strong interaction, with confinement as the signature), and phase restriction (the weak interaction, with exponential suppression as the signature). The underlying structure is characterized minimally---by exactly the properties the classification requires and no others---and is read informationally rather than mechanically: the working hypothesis is that entanglement structure is prior, with spacetime, fields, and particles as its effective descriptions. The classification is shown to be consistent with, though not derived from, two bodies of established work: the entropic derivations of the Einstein equations, which treat gravity as thermodynamic bookkeeping of vacuum entanglement, and the lattice evidence that confinement is topological in origin. The framework asserts no mechanism for mass, no preferred frame, and no microphysics of the underlying degrees of freedom. What is claimed and what is not is stated explicitly throughout.