{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/cosmic-chronometers-pantheon-supernovae-and","title":"Cosmic chronometers, Pantheon+ supernovae, and quasars favor coasting cosmologies over the flat $Λ$CDM model","arxiv_id":"2412.15717","date":"2024-12-20","proceeding":null,"authors":["Peter Raffai","Adrienn Pataki","Rebeka L. Böttger","Alexandra Karsai","Gergely Dálya"],"abstract":"We test and compare coasting cosmological models with curvature parameters ${k=\\left\\{ -1,0,+1 \\right\\}}$ in ${H_0^2 c^{-2}}$ units and the flat $\\Lambda$CDM model by fitting them to cosmic chronometers (CC), the Pantheon+ sample of type Ia supernovae (SNe), and standardized quasars (QSOs). We used the \\texttt{emcee} code for fitting CC data, a custom Markov Chain Monte Carlo implementation for SNe and QSOs, and Anderson-Darling tests for normality on normalized residuals for model comparison. Best-fit parameters are presented, constrained by data within redshift ranges $z\\leq 2$ for CCs, $z\\leq 2.3$ for SNe, and $z\\leq 7.54$ for QSOs. Coasting models, particularly the flat coasting model, are generally favored over the flat $\\Lambda$CDM model. The overfitting of the flat $\\Lambda$CDM model to Pantheon+ SNe and the large intrinsic scatter in QSO data suggest a need to refine error estimates in these datasets. We also highlight the seemingly fine-tuned nature of either the CC data or $\\Omega_{\\mathrm{m},0}$ in the flat $\\Lambda$CDM model to an ${H_1=H_0}$ coincidence when fitting ${H(z)=H_1z+H_0}$, a natural feature of coasting models.","url_abs":"https://arxiv.org/abs/2412.15717v1","url_pdf":"https://arxiv.org/pdf/2412.15717v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"cosmic-chronometers-pantheon-supernovae-and","repo_url":"https://zenodo.org/record/14184660","is_official":1,"mentioned_in_paper":0,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}