A theoretical proposal dubbed twinor theory is put forward as the spacetime-based counterpart to twistor theory. Rather than starting from the projective ray space, it is formulated via holomorphic reductive Cartan geometry modelled on complexified anti-de Sitter space, (A)dS₄^ℂ. The fundamental object is the spin-tractor bundle: its symmetric powers define ladder twinors, and their extremal Lorentz components define chiral twinors.

The formal core is a single field equation, D𝐘 = 𝐉, whose adjacent contractions and mixed divergence are fixed by source relations, with no additional equation imposed on its completely symmetric projection. On a flat, torsion-free Lorentzian background, the adjacent equations with the mass-normalization source reproduce the massive Dirac–Fierz–Pauli system, while the massless chiral realization yields the zero-rest-mass equations. Within this fixed mass normalization, the reality condition giving a positive real m² is the anti-de Sitter reality condition at the particle scale, independent of the cosmological scale and of the background curvature.

Nonlinear gravity is formulated through the full adjoint curvature: energy–momentum and spin currents specify Einstein–Cartan dynamics without requiring an explicit action. The adjoint Bianchi identity constrains source compatibility, and a BGG-type sequence organizes torsion-free infinitesimal deformations. Matter interactions enter through the coupled connection and contracted source relations, with curvature compatibility recorded by D𝐉 = ℱ_D 𝐘.

Among the highlighted consequences is the presence of the mass-coupling phase in the classical connection before quantization, together with the retention of both chiralities. The authors explicitly distinguish the additional consistency requirements for interacting higher-spin fields from the underlying bundle construction, which does not by itself impose them. This is a formal framework, with no new numerical predictions or phenomenological analysis in this first formulation.