psi-continuum-v2 0.2.3

Psi-Continuum v2: cosmological framework and joint likelihood analysis for the Psi-CDM model.

Psi-Continuum v2

A minimal one-parameter phenomenological extension of the ΛCDM cosmological model

Author: Dmitry V. Klimov
Status: Final archived research release (v0.2.3)

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Overview

Psi-Continuum v2 (ΨCDM) is a minimal background-level extension of the standard ΛCDM cosmological model.
It introduces a single dimensionless late-time deformation parameter ε₀ while not introducing any modifications to early-Universe physics or standard perturbation dynamics.

The model is designed for transparent, reproducible testing of late-time cosmological expansion using modern observational datasets.

This repository represents the final archived software release associated with the Psi-Continuum v2 publication.

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Model Definition

The modified Hubble expansion rate is defined as:

H_Ψ(z) = H_Λ(z) · (1 + ε₀ / (1 + z))

Properties of the parametrisation:

• Exact recovery of ΛCDM when ε₀ = 0
• Percent-level deviations only at low redshift
• Suppressed modifications as z → ∞
• No impact on early-Universe observables (CMB, primordial BAO)

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Installation

Install the package from PyPI:

pip install psi-continuum-v2

Important notes

• Scientific datasets are not included in the PyPI package.
• Generated results (results/) are not included.
• All datasets must be downloaded separately using the built-in tools.

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Command-Line Interface (CLI)

Psi-Continuum v2 provides an interactive and scriptable CLI.

Interactive menu

psi-cli

Menu options include:

• Download datasets
• Check datasets
• Run full analysis pipeline
• Open documentation
• Show project paths

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Built-in commands

Download all required datasets:

psi-download-data

Verify dataset integrity and paths:

psi-check-data

Run the complete analysis pipeline:

psi-run-all

These commands reproduce all numerical results and figures reported in the Psi-Continuum v2 publication.

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Documentation and Source Code

• Documentation: https://psi-continuum.org/docs/v2
• Source code: https://github.com/dmitrylife/psi-continuum-v2

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Publications and DOIs

• Psi-Continuum v2 preprint:
  DOI: https://doi.org/10.5281/zenodo.17879744

• Psi-Continuum v2 software archive:
  DOI: https://doi.org/10.5281/zenodo.17928837

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Project Status

This is a final archived research release.

The codebase is frozen and preserved for long-term reproducibility and citation. Future developments of the Psi-Continuum framework will be released as separate repositories and publications.

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Contact

Dmitry V. Klimov
Email: [e-mail]
Website: https://psi-continuum.org