CoreLumen Observational Series IV-B2 : Weak-Lensing Extension of the Growth Constraint

This record documents an extension of the CoreLumen cosmologicallikelihood pipeline through the inclusion of weak lensing constraints. COS IV-B2 builds upon the COS IV-B1 likelihood framework, whichcombined BAO, RSD, Planck priors, and CMB lensing information.The present stage incorporates an additional weak lensing constraintexpressed through the S8 parameter. The likelihood used in this analysis is χ² = χ²_BAO + χ²_RSD + χ²_Planck + χ²_CMB lensing + χ²_WL. The weak lensing contribution is implemented through thecompressed constraint S8 = σ8 √(Ωm / 0.3). The parameter space explored is (p1, σ8, Ωm). The resulting best-fit parameters remain consistent with thoseobtained in COS IV-B1 p1 ≈ −0.27σ8 ≈ 0.81Ωm ≈ 0.315 while the allowed parameter region becomes further constrained. The inclusion of weak lensing therefore acts primarily as adegeneracy-reduction test for the growth deformation framework,confirming the stability of the inferred parameter region underadditional lensing-sector constraints. This document serves as an archival record of the weak-lensingextension of the CoreLumen observational pipeline and is notintended as a journal submission.