Structural Cosmology v3.7: Multi-Survey Integration and Extended Structural Tests

Structural Cosmology v3.7 extends the Euclid DR1 integration framework developed in v3.6 into a comprehensive multi-survey program incorporating seven complementary observational probes: Euclid, DESI DR2, LSST/Rubin, CMB-S4, SKA/21cm, GW standard sirens, and SN Ia distance measurements. This release introduces a unified joint-likelihood architecture, cross-probe mapping operators, survey complementarity analysis, cross-probe consistency diagnostics, combined GGPT constraint forecasts, multi-survey nonlinear assessments, and an expanded falsifiability network (C1–C72). The central illustrative prediction remains the GGPT (Gravitational-Geometric Projection Test), characterized by a possible geometry-growth decoupling Δ(fσ₈) ≈ −5% to −7% at redshift z ≈ 1.0–1.5. A multi-survey integration framework is developed to evaluate this prediction across independent observational probes while accounting for survey-specific nuisance parameters and consistency diagnostics. This version serves as the final integration stage before v3.8 (Statistical Inference Framework), which will introduce full Bayesian inference, model selection, hierarchical likelihood structures, and cross-probe covariance modeling. All measurements, posterior distributions, forecasts, sensitivity estimates, network statistics, and figures presented in this release are illustrative framework examples intended for methodology development and reproducibility demonstration. Final scientific conclusions require future analyses using real observational data and complete systematic treatments. Keywords: Structural Cosmology, Multi-Survey Integration, GGPT, Joint Likelihood, Cross-Probe Consistency, Euclid, DESI, LSST, CMB-S4, SKA, Gravitational Waves, Non-Gaussianity, Bayesian Inference, Survival Network.