{"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/the-dark-energy-survey-supernova-program-slow","title":"The Dark Energy Survey Supernova Program: Slow supernovae show cosmological time dilation out to $z \\sim 1$","arxiv_id":"2406.05050","date":"2024-06-07","proceeding":null,"authors":["R. M. T. White","T. M. Davis","G. F. Lewis","D. Brout","L. Galbany","K. Glazebrook","S. R. Hinton","J. Lee","C. Lidman","A. Möller","M. Sako","D. Scolnic","M. Smith","M. Sullivan","B. O. Sánchez","P. Shah","M. Vincenzi","P. Wiseman","T. M. C. Abbott","M. Aguena","S. Allam","F. Andrade-Oliveira","J. Asorey","D. Bacon","S. Bocquet","D. Brooks","E. Buckley-Geer","D. L. Burke","A. Carnero Rosell","D. Carollo","J. Carretero","L. N. da Costa","M. E. S. Pereira","J. De Vicente","S. Desai","H. T. Diehl","S. Everett","I. Ferrero","B. Flaugher","J. Frieman","J. García-Bellido","E. Gaztanaga","G. Giannini","R. A. Gruendl","D. L. Hollowood","K. Honscheid","D. J. James","R. Kessler","K. Kuehn","O. Lahav","S. Lee","M. Lima","J. L. Marshall","J. Mena-Fernández","R. Miquel","J. Myles","R. C. Nichol","R. L. C. Ogando","A. Palmese","A. Pieres","A. A. Plazas Malagón","A. K. Romer","E. Sanchez","D. Sanchez Cid","M. Schubnell","E. Suchyta","G. Tarle","B. E. Tucker","A. R. Walker","N. Weaverdyck"],"abstract":"We present a precise measurement of cosmological time dilation using the light curves of 1504 type Ia supernovae from the Dark Energy Survey spanning a redshift range $0.1\\lesssim z\\lesssim 1.2$. We find that the width of supernova light curves is proportional to $(1+z)$, as expected for time dilation due to the expansion of the Universe. Assuming type Ia supernovae light curves are emitted with a consistent duration $\\Delta t_{\\rm em}$, and parameterising the observed duration as $\\Delta t_{\\rm obs}=\\Delta t_{\\rm em}(1+z)^b$, we fit for the form of time dilation using two methods. Firstly, we find that a power of $b \\approx 1$ minimises the flux scatter in stacked subsamples of light curves across different redshifts. Secondly, we fit each target supernova to a stacked light curve (stacking all supernovae with observed bandpasses matching that of the target light curve) and find $b=1.003\\pm0.005$ (stat) $\\pm\\,0.010$ (sys). Thanks to the large number of supernovae and large redshift-range of the sample, this analysis gives the most precise measurement of cosmological time dilation to date, ruling out any non-time-dilating cosmological models at very high significance.","url_abs":"https://arxiv.org/abs/2406.05050v2","url_pdf":"https://arxiv.org/pdf/2406.05050v2.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":"the-dark-energy-survey-supernova-program-slow","repo_url":"https://github.com/ryanwhite1/DES-Time-Dilation","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}