{"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/improved-cosmological-constraints-from-a","title":"Improved cosmological constraints from a joint analysis of the SDSS-II and SNLS supernova samples","arxiv_id":"1401.4064","date":"2014-01-16","proceeding":null,"authors":["M. Betoule","R. Kessler","J. Guy","J. Mosher","D. Hardin","R. Biswas","P. Astier","P. El-Hage","M. Konig","S. Kuhlmann","J. Marriner","R. Pain","N. Regnault","C. Balland","B. A. Bassett","P. J. Brown","H. Campbell","R. G. Carlberg","F. Cellier-Holzem","D. Cinabro","A. Conley","C. B. D'Andrea","D. L. DePoy","M. Doi","R. S. Ellis","S. Fabbro","A. V. Filippenko","R. J. Foley","J. A. Frieman","D. Fouchez","L. Galbany","A. Goobar","R. R. Gupta","G. J. Hill","R. Hlozek","C. J. Hogan","I. M. Hook","D. A. Howell","S. W. Jha","L. Le Guillou","G. Leloudas","C. Lidman","J. L. Marshall","A. Möller","A. M. Mourão","J. Neveu","R. Nichol","M. D. Olmstead","N. Palanque-Delabrouille","S. Perlmutter","J. L. Prieto","C. J. Pritchet","M. Richmond","A. G. Riess","V. Ruhlmann-Kleider","M. Sako","K. Schahmaneche","D. P. Schneider","M. Smith","J. Sollerman","M. Sullivan","N. A. Walton","C. J. Wheeler"],"abstract":"We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The data set includes several low-redshift samples (z<0.1), all 3 seasons from the SDSS-II (0.05 < z < 0.4), and 3 years from SNLS (0.2 <z < 1) and totals \\ntotc spectroscopically confirmed type Ia supernovae with high quality light curves. We have followed the methods and assumptions of the SNLS 3-year data analysis except for the following important improvements: 1) the addition of the full SDSS-II spectroscopically-confirmed SN Ia sample in both the training of the SALT2 light curve model and in the Hubble diagram analysis (\\nsdssc SNe), 2) inter-calibration of the SNLS and SDSS surveys and reduced systematic uncertainties in the photometric calibration, performed blindly with respect to the cosmology analysis, and 3) a thorough investigation of systematic errors associated with the SALT2 modeling of SN Ia light-curves. We produce recalibrated SN Ia light-curves and associated distances for the SDSS-II and SNLS samples. The large SDSS-II sample provides an effective, independent, low-z anchor for the Hubble diagram and reduces the systematic error from calibration systematics in the low-z SN sample. For a flat LCDM cosmology we find Omega_m=0.295+-0.034 (stat+sys), a value consistent with the most recent CMB measurement from the Planck and WMAP experiments. Our result is 1.8sigma (stat+sys) different than the previously published result of SNLS 3-year data. The change is due primarily to improvements in the SNLS photometric calibration. When combined with CMB constraints, we measure a constant dark-energy equation of state parameter w=-1.018+-0.057 (stat+sys) for a flat universe. Adding BAO distance measurements gives similar constraints: w=-1.027+-0.055.","url_abs":"http://arxiv.org/abs/1401.4064v2","url_pdf":"http://arxiv.org/pdf/1401.4064v2.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":"improved-cosmological-constraints-from-a","repo_url":"https://github.com/CobayaSampler/sn_data","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":{"status":"ok"}},{"paper_slug":"improved-cosmological-constraints-from-a","repo_url":"https://github.com/CosmoStats/cosmostats2018-jzsmoreno","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"improved-cosmological-constraints-from-a","repo_url":"https://github.com/CosmoStats/projectofinal1-2018-all","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"improved-cosmological-constraints-from-a","repo_url":"https://github.com/congma/libsncompress","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"improved-cosmological-constraints-from-a","repo_url":"https://github.com/valerio-marra/mBayes","is_official":0,"mentioned_in_paper":0,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"improved-cosmological-constraints-from-a","repo_url":"https://gitlab.com/congma/libsncompress","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}