The ΛCDM model describes the cosmic microwave background (CMB) power spectrum with six free parameters whose values are determined empirically and remain unexplained from first principles. We show that all six parameters are fixed — without any fitting — by a single geometric object: a rank-5 non-invertible projection Π : M⁵ → R⁴ of a neutral Majorana spinor. The projection imposes a characteristic palindromic equation on the boundary operator spectrum whose three admissible solutions correspond precisely to the three CMB spectral regimes: the Sachs–Wolfe plateau, the acoustic peak ladder, and the Silk damping tail. The six cosmological parameters emerge as exact structural identities. The spectral tilt nₛ = 0.96482 is an arithmetic residue of the Ramanujan–Heegner index 163. The baryon density Ωbh² = √5/100 = 0.022361 is the irrational Silk residue of the palindromic boundary, consistent with Planck 2018 at 0.06σ and independently with Big Bang nucleosynthesis at 0.5σ. The dark matter density Ωch² = 1/(5φ) = 0.12361 follows from the active fraction of the projection kernel. The optical depth τ = 7/130, the Hubble rate H₀ ≃ 67.9 km/s/Mpc, and the scalar amplitude Aₛ = 2.101×10⁻⁹ are fixed by the boundary return cycle and the Heegner–Gaussian transfer integral, respectively. With all six parameters derived and no free cosmological degrees of freedom, CAMB reproduces the Planck 2018 TT power spectrum with χ²ᵥ = 1.18, compared to χ²ᵥ = 1.04 for ΛCDM with six fitted parameters. Six acoustic peak amplitudes are reproduced at RMS 5.20% and six TE polarisation nodes at RMS 1.7%. The spectral tilt nₛ = 0.96482 constitutes a sharp, parameter-free prediction testable by Simons Observatory and CMB-S4. A reproducibility package (CAMB scripts, Planck data, BBN check, metrics) is included in the support archive.
Pasquale Camelia (Fri,) studied this question.