v1.0.0 — Phantom Crossing as Template Artifact (EPJ Plus submission)

Reproducibility package for the manuscript:

B. Shatto, "Phantom Crossing as Template Artifact: The Λcos Distance-Redshift Model from Bounded Topology" — submitted to European Physical Journal Plus, 2026.

Contents

• Data (data/): Pantheon+ SNe Ia (1701 entries) and DESI DR2 BAO (13 observables) with full covariance matrices.
• Scripts (scripts/): seven Python files reproducing every quantitative claim:
  • fit_lcdm.py — flat ΛCDM baseline (§5.2)
  • fit_lcos.py — Λcos primary fit at Ω_Λ = 0.685 (§5.2)
  • fit_wcdm.py — wCDM model comparison with ΔAIC/ΔBIC (§5.7)
  • fit_clock_exponents.py — Appendix A clock-exponent fits (Models A–D)
  • template_bias.py — Fig. 1 mock fits (CPL/BA/JBP/Polynomial)
  • threshold_scan.py — Fig. 2 CPL recovered (w₀, wₐ) vs s₀
  • make_plots.py — Fig. 3 corner + Fig. 4 residuals
• Chains and posteriors (results/): bit-for-bit script outputs, 79 MB. Every figure and table in the paper regenerates from these.
• Figures (figures/): four published PDFs.
• Tables (tables/): Appendix A canonical fit values.

Reproducibility

git clone https://github.com/dmobius3/lambdacos.git
cd lambdacos
python -m venv venv && source venv/bin/activate
pip install -r requirements.txt
cd scripts
python fit_lcdm.py && python fit_lcos.py && python fit_wcdm.py
python fit_clock_exponents.py
python template_bias.py && python threshold_scan.py
python make_plots.py