Code Repository for 'A Case for an Inhomogeneous Einstein-de Sitter Universe'

The repository contains Python code to test the iEdS and flat ΛCDM cosmological models against the DESI DR2 BAO and Pantheon+ SNIa datasets. Parameter estimation is performed with dynesty’s DynamicNestedSampler (see the article and documentation). Additionally, we evaluate the goodness of a camb fit (see the article and documentation) with respect to the Planck 2018 CMB TT power spectrum. Detailed descriptions and usage instructions are included within the code file.

Required input files:

• BAO measurements and covariance: DESI_DR2_BAO.txt and DESI_DR2_BAO_Cov.txt (included in this repository). Source: CobayaSampler/bao_data/desi_bao_dr2;
• SN data and covariance: available at PantheonPlusSH0ES/DataRelease;
• CMB baseline Planck TT power spectra can be obtained from: COM_PowerSpect_CMB-TT-full_R3.01.txt;
• camb fit results (included): camb_iEdS1.dat, camb_iEdS2.dat, camb_LCDM.dat;
  camb fits use Planck best fit parameters from planck_2018.ini and COM_PowerSpect_CMB-base-plikHM-TTTEEE-lowl-lowE-lensing-minimum_R3.01.txt.

The repository includes a zipped archive of fit outputs: results.zip. A detailed description of all files inside the archive is provided in results.zip/README.rtf.

The repository also includes PDF files that present the fit results as corner plots, illustrating the posterior distributions of the fitted parameters. These plots display the projections of the dynesty samples in one- and two-dimensional parameter spaces. The 1D histograms show the median of the posterior parameter distributions, along with the 1σ uncertainties represented by the 16th and 84th percentiles. In the 2D distribution panels, contours are plotted at 0.5σ, 1σ, 1.5σ, and 2σ levels.

Corresponding author of the article: Peter Raffai, peter.raffai@ttk.elte.hu
Corresponding author of the repository: Adrienn Pataki, patakia@student.elte.hu