{"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/a-w-phantom-transition-at-z-t-0-1-as-a","title":"A $w-M$ phantom transition at $z_t<0.1$ as a resolution of the Hubble tension","arxiv_id":"2012.13932","date":"2020-12-27","proceeding":null,"authors":["George Alestas","Lavrentios Kazantzidis","Leandros Perivolaropoulos"],"abstract":"A rapid phantom transition of the dark energy equation of state parameter $w$ at a transition redshift $z_t<0.1$ of the form $w(z)=-1+\\Delta w\\;\\Theta (z_t-z)$ with $\\Delta w<0$ can lead to a higher value of the Hubble constant while closely mimicking a Planck18/$\\Lambda$CDM form of the comoving distance $r(z)=\\int_0^z\\frac{dz'}{H(z')}$ for $z>z_t$. Such a transition however would imply a significantly lower value of the SnIa absolute magnitude $M$ than the value $M_C$ imposed by local Cepheid calibrators at $z<0.01$. Thus, in order to resolve the $H_0$ tension it would need to be accompanied by a similar transition in the value of the SnIa absolute magnitude $M$ as $M(z)=M_C+\\Delta M \\;\\Theta (z-z_t)$ with $\\Delta M<0$. This is a Late $w-M$ phantom transition ($LwMPT$). It may be achieved by a sudden reduction of the value of the normalized effective Newton constant $\\mu=G_{\\rm{eff}}/G_{\\rm{N}}$ by about $6\\%$ assuming that the absolute luminosity of SnIa is proportional to the Chandrasekhar mass which varies as $\\mu^{-3/2}$. We demonstrate that such an ultra low $z$ abrupt feature of $w-M$ provides a better fit to cosmological data compared to smooth late time deformations of $H(z)$ that also address the Hubble tension. For $z_t=0.02$ we find $\\Delta w\\simeq -4$, $\\Delta M \\simeq -0.1$. This model also addresses the growth tension due to the predicted lower value of $\\mu$ at $z>z_t$. A prior of $\\Delta w=0$ (no $w$ transition) can still resolve the $H_0$ tension with a larger amplitude $M$ transition with $\\Delta M\\simeq -0.2$ at $z_t\\simeq 0.01$. This implies a larger reduction of $\\mu$ for $z>0.01$ (about $12\\%$). The $LwMPT$ can be generically induced by a scalar field non-minimally coupled to gravity with no need of a screening mechanism since in this model $\\mu=1$ at $z<0.01$.","url_abs":"https://arxiv.org/abs/2012.13932v4","url_pdf":"https://arxiv.org/pdf/2012.13932v4.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":"a-w-phantom-transition-at-z-t-0-1-as-a","repo_url":"https://github.com/GeorgeAlestas/LwMPT","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null},{"paper_slug":"a-w-phantom-transition-at-z-t-0-1-as-a","repo_url":"https://github.com/GeorgeAlestas/LwPT","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"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}