Late-time cosmology from the B-Project: modular dynamics, dynamical ψ(a), ISW signatures, and multi-redshift BAO constraints

This deposit provides the full numerical and data-analysis pipelines accompanying the preprint “Late-time cosmology from the B-Project: modular dynamics, dynamical ψ(a), ISW signatures, and multi-redshift BAO constraints.” It includes two independent Boltzmann-solver implementations: • a CAMB-based pipeline• a CLASS-based pipeline (via Cobaya) Both pipelines implement late-time B-Project dynamics only, while preserving early-universe physics, including recombination and the baryon-drag sound horizon. The deposit contains: • all BAO distance ratios used in the paper,• BAO-driven H0H0 scans and mappings,• early-universe consistency checks (z∗z∗ and rdragrdrag),• large-scale CMB temperature spectra illustrating the late Integrated Sachs–Wolfe (ISW) regime,• growth-of-structure results, including the observable fσ8(z)fσ8(z),• machine-readable tables (CSV) for all reported numerical values. Legacy labels “CET Ω” appearing in some filenames or console outputs correspond to the same late-time B-Project sector and reflect naming conventions used during early development stages. Execution and reproducibility.All numerical results were generated using locally compiled Boltzmann solvers.The CAMB pipeline relies on a custom-built CAMB installation with late-time dark-energy extensions, while the CLASS pipeline is implemented via Cobaya.Each numerical table and figure in the manuscript can be reproduced by executing the corresponding scripts provided in this deposit, using the parameter files included.No external proprietary data or undocumented preprocessing steps are required.