CPQ Theory: Cosmic Birefringence as a Signature of Matrix Chirality

Within CPQ theory, the reported cosmic birefringence angle of order β_CMB ~ 0.2°–0.3° in Planck, WMAP and ACT polarization analyses is interpreted as a direct signature of the global chirality Ξ₀ of the spacetime matrix. The Chern–Simons torsion term η·T·(∇×T) in the full Matrix Lagrangian distinguishes left- and right-circular polarisations of the photon-torsion mode, producing a helicity-dependent phase shift that integrates into a rotation of the linear polarisation plane of CMB photons. The compact CPQ ansatz β_CMB ≈ 2α_fs·Ξ₀ gives β ≈ 0.307° for Ξ₀ = 1/e, close to the reported value. The same chirality parameter Ξ₀ enters the CPQ interpretation of the spectral index n_s, neutrino handedness, and galactic spin asymmetry, providing multi-observable consistency from a single non-fitted parameter. The local linear birefringence mechanism — Chern–Simons-induced helicity splitting, bilinear scaling in η·Ξ₀, frequency-independence, and direct rotation of linear polarisation — is independently verified by 3D lattice simulation (Sim 7) on an NVIDIA Tesla P40, with sub-percent agreement to the analytic prediction across all tested parameter regimes. The article also predicts a small anisotropic component β(n̂) aligned with a preferred cosmic axis, which would discriminate CPQ from homogeneous axion-like models in upcoming Simons Observatory and LiteBIRD data. [1] Porschová, A. (2026). The Matrix — Parameters and Dynamics: Foundation of CPQ Theory (v3.1). Zenodo. https://doi.org/10.5281/zenodo.19431867 [2] Porschová, A. (2026). CPQ Field Theory — Applications: From Empty Matrix to the Standard Model and Chemistry and to Cosmology (Books 01–03). Zenodo. https://doi.org/10.5281/zenodo.19100819 [3] Porschová, A. (2026). CPQ Theory — A Unified Framework from Spacetime Quanta to Cosmology (Books I–III) (v1.4). Zenodo. https://doi.org/10.5281/zenodo.18686137