We present a simultaneous two-dimensional global likelihood analysis of the U-Cell Model (UCM) and ΛCDM over the parameter space (H₀, Ωₘ), combining DESI DR2 BAO, eBOSS DR16 BAO, and Cosmic Chronometer (CC) likelihoods (N = 61 data points). This directly addresses the methodological concern that per-probe BIC summation may overlook cross-dataset correlations. The UCM fixes Ωₘ = 0. 3166 algebraically (zero free cosmological parameters) ; ΛCDM treats Ωₘ as a free parameter. The global fit yields three main results: (1) The UCM joint constraint on the Hubble constant is H₀ = 67. 6 ± 0. 3 km/s/Mpc, consistent with Planck at 0. 9σ. The UCM confirms the CMB-derived value and does not resolve the Hubble tension — which is an observational discrepancy distinct from the theoretical cosmological constant problem the UCM addresses. (2) The BAO+CC global ΔBIC = −2. 25 (inconclusive on the Jeffreys scale; threshold > 2), meaning BAO+CC data alone do not significantly distinguish UCM from ΛCDM. The decisive evidence in Paper 28 (ΣΔBIC = +27. 1) comes from the supernova sector (three independent compilations, ΔBIC = +18. 3 combined), which is unaffected by BAO-CC correlations. (3) The Cosmic Chronometers alone prefer Ωₘ = 0. 320 ± 0. 020 (Paper 17), consistent with UCM at 0. 2σ. The 2. 6σ BAO+CC tension with Ωₘ = 0. 3166 is driven by DESI DR2 and eBOSS DR16, which prefer lower Ωₘ independently of the UCM — a probe-internal tension also present in DESI DR2 vs. Planck ΛCDM. The analysis code (ucmglobalfit. py) and Cobaya configuration files are included for full reproducibility. Part of the UCM preprint series (ORCID 0009-0005-5088-4339, records 19387201–19413958).
Norbert Prebeck (Sat,) studied this question.