{"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/constraining-cosmological-parameters-based-on","title":"Constraining Cosmological Parameters Based on Relative Galaxy Ages","arxiv_id":"astro-ph/0106145","date":"2001-06-07","proceeding":null,"authors":["Raul Jimenez","Abraham Loeb"],"abstract":"We propose to use relative galaxy ages as a means of constraining cosmological parameters. By measuring the age difference between two ensembles of old galaxies at somewhat different redshifts, one could determine the derivative of redshift with respect to cosmic time, dz/dt. At high redshifts, z=1-2, this measurement would constrain the equation-of-state of the dark energy, while at low redshifts, z< 0.2, it would determine the Hubble constant, H_0. The selected galaxies need to be passively-evolving on a time much longer than their age difference.","url_abs":"https://arxiv.org/abs/astro-ph/0106145v1","url_pdf":"https://arxiv.org/pdf/astro-ph/0106145v1.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":"constraining-cosmological-parameters-based-on","repo_url":"https://github.com/sunnyvagnozzi/CosmoMC-patches","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}