Dark Energy as Cosmological QEC Landauer Exhaust on the Z3 ⊗Q3 Substrate: KMS Temperature, Holographic Boundary Crystallization, and the 80/20 Dark Matter Composition

We derive the dark sector — dark energy density, equation of state, dark matter com- position, and galactic-scale signatures — from a single thermodynamic closure on the dis- crete Z3 ⊗Q3 substrate of the Holographic Circlette (TCH) framework. The restoring force RΛ in the substrate’s Lindbladian master equation operates as a literal Maxwell’s Demon: it locally reduces matter-state entropy by pumping localized Q-subspace defects back into coherent SU(3) superpositions to avert the Variational Catastrophe. To pre- serve the Second Law, this quantum-error-correction (QEC) cycle must export entropy as Landauer waste heat. We formalize this as a four-stroke thermodynamic engine and demonstrate five structural closures. (I) The Kubo–Martin–Schwinger (KMS) detailed- balance condition on the Lindbladian semigroup fixes the substrate temperature exactly as Tsubstrate = αΛQCD/(kBln 2) ≈4.05 ×1010 K. (II) Cosmological expansion proceeds by Holographic Boundary Crystallization: new Q3 matter cells precipitate at the cosmological horizon to keep the Bekenstein–Hawking bound saturated against the incoming Landauer flux. The universe does not stretch; it prints new boundary nodes to accommodate its own computational exhaust. (III) The Past Hypothesis is recast as a structural property: newly generated nodes enter existence with strictly zero entanglement entropy, providing an infinite low-entropy cold bath that prevents heat death. (IV) A 3/4 rule-class pro- jection (three geometric stabilizers R1, R2, R3 radiating uniform vacuum exhaust vs the matter-anchored R4 = W) tightens the dark energy magnitude from a 28% overshoot to a 4% match (ρexact Λ = 2.4 ×10−47 GeV4 vs observed 2.5 ×10−47 GeV4). (V) The same 3-axis partition recovers the factor of 3 in the denominator of the de Sitter Friedmann equation H2 = ρΛ/(3M2 P) structurally rather than from generic 3+1 dimensionality. Com- bining the rule-class partition with the cube Euler–Poincar´e invariant E/b1 = 12/5 yields an algebraically exact 80/20 dark matter composition: 80% bound R4 QEC exhaust (a substrate-specific substance category — not standard CDM, WDM, or dark radiation) plus 20% sterile right-handed Majorana neutrinos at mνR = α2ΛQCD ≈17.7 keV. This composition natively resolves the three small-scale crises of ΛCDM cosmology: (i) cored density profiles in dwarf spheroidals from the 80% topological-fluid pressure support; (ii) suppression of substructure below∼108M⊙ from the 50 kpc free-streaming length of the 20% particulate component; (iii) smooth bound-radiation halos up to the virial radius R200 as a uniquely TCH-distinguishing signature. The framework predicts a sharp 17.7 keV X-ray decay line as a direct spectroscopic test (XRISM, Athena timelines) and structure- formation corrections to w(z) falsifiable against DESI Y3 / Euclid Y2 measurements. The full derivation chain extends without phenomenological inputs from single-bit Pauli algebra to dwarf-galaxy rotation curves.