CoreLumen Observational Series II : Full-Likelihood Validation with BOSS DR12

This record documents the second entry in the CoreLumen Observational Series (COS). COS II performs a full-likelihood validation of the late-time growth deformationindication previously identified in COS I. The analysis uses the BOSS DR12consensus BAO+RSD dataset, including the full 9×9 covariance matrix acrossthree effective redshift bins. A minimal phenomenological modification confined to the linear growth sectoris tested using a single deformation parameter p1 that modifies the effectivegrowth kernel through μ(a) = 1 + p1(1 − a). The likelihood structure is evaluated through one-dimensional likelihood scans,two-dimensional degeneracy contours, residual diagnostics, and profilelikelihood calculations over σ8. The results show that the apparent growth deformation signal suggested bycompressed analyses is largely driven by a degeneracy between the deformationparameter p1 and the matter fluctuation amplitude σ8. When σ8 is profiled,the statistical preference for a non-zero deformation parameter becomes mild. This Zenodo record provides a fully reproducible archive of the COS IIanalysis pipeline, including the likelihood implementation, numericalmethods, data inputs, and figure outputs used in the manuscript. COS II serves as a validation step in the CoreLumen Observational Series,documenting the degeneracy structure of the DR12 dataset and establishinga reproducible baseline for subsequent analyses using DESI-era dataand multi-probe observational combinations.