Why the Standard Cosmological Causal Chain Is Backwards

Standard cosmology holds that the cosmological constant Λ drives the expansion of the universe and that the Hubble rate H₀ is the observed consequence. This paper argues the arrow runs the other way.

The Pentagon Physics bridge partition 1 = φ⁻¹ + φ⁻² forces the exact identity R_Λ = 2R_H, where R_Λ = 2/√5 and R_H = 1/√5 are the bridge ratios of Λ and H₀ respectively. Λ sits at twice the derivation depth of H₀. In the bridge template, depth determines structural priority: Λ requires H₀ to be defined, not the reverse. The cosmological constant is H₀ making a round trip, the closed returning version of the one-way Hubble departure.

The paper derives H₀ = 71.7 km/s/Mpc from the axiom σ = 1/(1+σ) with zero free parameters, placing the prediction between the SH0ES distance-ladder value (73.0 ± 1.0, 1.3σ) and the TRGB measurement (69.8 ± 1.7, 1.1σ), and 8.5σ from Planck. The paper argues this pattern is structural: Λ-CDM extractions constrain Ω_Λ and H₀ jointly, producing a systematic offset that the PP bridge structure predicts. Model-independent distance-ladder measurements do not embed this joint constraint and cluster near the PP value.

A companion identity, R_G + R_floor = R_H, identifies gravity as the component of the Hubble departure that escaped without its floor fraction, connecting G, H₀, and Λ in a single algebraic object. Three falsification conditions are stated, including a specific CMB test: if a lensing-only or geometry-only CMB analysis produces H₀ > 71 km/s/Mpc, the causal inversion interpretation fails.

This paper is a companion to The Bridges of Pentagon Physics (Zenodo, 2026), which establishes the full partition taxonomy.

Keywords: Hubble tension, cosmological constant, Hubble constant, causal structure, golden ratio, Pentagon Physics, self-referential axiom, vacuum energy