Codes for paper — Phenomenological Dark Energy model with hybrid dynamic Cosmological Constant
Creators: name: Aich, Arkajit
Publisher: name: Zenodo
Year: 2021
Subjects: Cosmology
Time varying Cosmological Constant
Dark Energy

description: This upload contains all the python codes used in the paper titled "Phenomenological Dark Energy model with hybrid dynamic Cosmological Constant" [1] in pdfLaTeX format. There are thirteen codes in the upload overall. A short description of what the codes do is given below – The code files having names in the format "hubble diagram ........... model union 2.1" fits supernova data from Union 2.1 collaboration [2] to various cosmological models including hybrid dynamic cosmological constant model (the model of the concerned paper) for estimating the relevant model parameters for flat Universe. Additionally, there is a code file named "hubble diagram ...............pantheon" that fits supernova data from the pantheon dataset [3] to hybrid dynamic cosmological constant model. The fitting procedure uses emcee [4] within the Lmfit module [5] of python which implements the Affine Invariant Markov Chain Monte Carlo (MCMC) method for extracting the model parameters. Publicly available Union 2.1 data has been presented in a .txt file named “union 2.1 sorted” for convenience. The tab-separated columns of union 2.1 sorted.txt stand for Redshift, Distance Modulus, and Distance Modulus Error respectively of union 2.1 Supernova data. Publicly available Pantheon data has been presented in three .txt files named "pantheon_z_sorted", "pantheon_magnitude_sorted", "pantheon_mag_error_sorted" which stands for Redshift, apparent magnitude, and apparent magnitude error respectively of pantheon Supernova data. The codes are written to read data directly from the respective .txt files. The code files named “scale factor evolution”, “deceleration parameter evolution”, and "proximity parameter evolution" plot the evolution of scale factor, deceleration parameter, and proximity parameter for both – standard ΛCDM model and hybrid dynamic cosmological constant model using the fitted values of parameters. The code files having names in the format "density parameters evolution ....... model" plot the evolution of density parameters for the respective models. The code file named "creation rate parameter evolution" plots the evolution of the creation rate parameter of the hybrid dynamic cosmological constant model. The code files having names in the format “derived Parameters estimation ....... model” calculates the derived Cosmological parameters - present-day deceleration parameter, transition redshift, and Age of the Universe for standard ΛCDM model and hybrid dynamic Cosmological Constant model. Additionally, the creation rate parameter is calculated for the hybrid dynamic cosmological constant model. Parts of the code that calculates Cosmic Age has been adapted from Fatima et al. [6]
description: The manuscript related to the codes has been published and available online at https://doi.org/10.1088/1361-6382/ac35ed.
description: {"references": ["[1] A. Aich, Class. Quantum Grav. 39 035010 (2022) https://doi.org/10.1088/1361-6382/ac35ed", "[2] N. Suzuki et al., Union2.1 Compilation Magnitude vs. Redshift Table (for your own cosmology fitter) (2012) http://supernova.lbl.gov/Union/", "[3] D.M. Scolnic et al., Catalogs of cosmologically useful type Ia supernovae from pan--STARRS (2018) https:// archive.stsci.edu/prepds/ps1cosmo/index.html", "[4] D. Mackey, D. Hogg, D. Lang and J. Goodman, Publ. Astron. Soc. Pac. 125, 306 (2013) https://doi.org/10.1086/670067", "[5] M. Newville, T. Stensitzki, D.Allen and A.Ingargiola, Lmfit Code, Zenodo (2014) https://doi.org/10.5281/zenodo.11813", "[6] H. Fatima, M. Mushtaq and S. Rahman, arXiv:1609.02480 (2016)"]}