Beyond ΛCDM: The CPT-Siamese Phase Mechanism as a Unified Solution to the Dark Energy, H₀ and σ₈ Tensions

This repository contains the full manuscript, figures, and numerical scripts supporting the paper:

“Beyond ΛCDM: The CPT-Siamese Phase Mechanism as a Unified Solution to the Dark Energy, H₀ and σ₈ Tensions.”

In this work, we present a phase-interference cosmological framework based on CPT-symmetric Siamese universes, where dark energy emerges dynamically from vacuum phase desynchronization, rather than from a fundamental cosmological constant. This single physical mechanism simultaneously addresses:

• The Hubble tension (H₀)
• The σ₈ structure growth tension
• Late-time acceleration anomalies
• The apparent breakdown of ΛCDM at low redshift

✅ Included in this repository:
This repository explicitly includes the Python script used to generate Figure 1 of the paper, corresponding to the comparative H(z) vs. z diagram between ΛCDM and Siamese cosmology. This ensures direct numerical reproducibility of the central observational result.

📌 Important note on additional figures:
The two additional key diagnostic figures used in the discussion — namely:

• The Expansion Turnover: H(z)/(1+z)
• The Deceleration Parameter q(z) confrontation with Son & Lee (2025)

are generated and fully documented in the companion reproducibility dataset hosted at:

👉 https://zenodo.org/records/17694936

“siamese-cosmic-deceleration: Replication Data & Code for:
‘Transient Cosmic Acceleration from Phase Interference: A Siamese Cosmology Confronted with Son & Lee (2025)’”

That companion repository contains the full code and numerical pipeline required to reproduce Figures 2 and 3 of the present paper.

🎯 Scientific scope:
This project demonstrates how transient cosmic acceleration, late-time deceleration, and dark energy phenomenology can arise from a single phase-interference mechanism operating in a CPT-symmetric dual-universe framework — without invoking exotic new fluids or fine-tuned vacuum constants.

🔁 Reproducibility:
All scripts are provided for full transparency and independent verification. The work follows an open-science philosophy with direct numerical reproducibility.