Zero-Parameter Cosmological Concordance
From entanglement entropy to 28 observables
Tests the entanglement entropy prediction Ω_Λ = 0.6877 against 28 cosmological observables — CMB, BAO, RSD, lensing, supernovae, and H₀ — with zero free dark energy parameters. Achieves lower total χ² than Planck ΛCDM and Bayes factor 70:1.
Mar 15, 2026 · Preprint
Plain English
This paper takes one predicted number — the strength of dark energy — and checks it against every major astronomical measurement available. It fits the data better than the standard model of cosmology, despite having one fewer adjustable constant.
The problem
The companion papers derived a specific value for the cosmological constant from quantum entanglement: Ω_Λ = 0.6877. But a theoretical prediction is worthless if it does not survive contact with reality. Does this single number actually agree with what telescopes measure — the cosmic microwave background, galaxy clustering, supernovae, gravitational lensing, and the expansion rate?
The key idea
From one predicted number, every other cosmological parameter follows: the matter density, the Hubble constant, the growth rate of structure, the age of the universe. Zero knobs to turn. The standard model of cosmology (ΛCDM) fits one free parameter to the data; this framework predicts that parameter from particle physics.
What the paper does
It tests the prediction against 28 independent measurements across five probe classes. Result: the framework achieves a total goodness-of-fit (χ²) of 172.65 across 26 data points, beating the Planck best fit of 178.02. It fits structure growth better than Planck (χ²/N = 0.75 vs 0.79). Bayesian model comparison yields a Bayes factor of 50–70 in the framework's favour — "very strong evidence" on the standard scale.
Why it matters
A zero-parameter theory that fits the data as well as (or better than) the best one-parameter model is extraordinary. The framework also predicts H₀ = 67.67 km/s/Mpc (consistent with Planck, 5σ from the distance ladder), neutrino mass Σmν = 0.06 eV (normal hierarchy), and w = −1 exactly. Pre-registered predictions for DESI Y3 (2027) and Euclid (2030) make the framework explicitly falsifiable.
What could go wrong
The BAO-only best fit is 2.3σ from the prediction — a 3.3% probability fluctuation that warrants monitoring. The DESI experiment hints at w ≠ −1 (4.1σ), which would kill the framework if confirmed by DESI Y5 (~2028). The S₈ and Hubble tensions are reduced but not resolved. This is a preprint and has not been peer-reviewed.