Dynamical dark energy in light of the DESI DR2 baryonic acoustic oscillations measurements

作者：Gan Gu, Xiaoma Wang, Yuting Wang, Gong‐Bo Zhao, Levon Pogosian, K. Koyama, J. A. Peacock, Zheng Cai, Jorge L. Cervantes–Cota, Mustapha Ishak, Arman Shafieloo, Ruiyang Zhao, S. P. Ahlen, Davide Bianchi, D. Brooks, T. Claybaugh, Shaun Cole, Axel de la Macorra, Arnaud de Mattia, P. Doel, Simone Ferraro, J. E. Forero-Romero, E. Gaztañaga, Satya Gontcho A Gontcho, G. Gutiérrez, ChangHoon Hahn, Cullan Howlett, R. Kehoe, D. Kirkby, Jean‐Paul Kneib, Anthony Kremin, O. Lahav, Martin Landriau, L. Le Guillou, Alexie Leauthaud, M. E. Levi, Marc Manera, Aaron Meisner, R. Miquel, John Moustakas, A. Muñoz-Gutiérrez, S. Nadathur, Jeffrey A. Newman, N. Palanque‐Delabrouille, Will J. Percival, Francisco Prada, Ignasi Pérez-Ràfols, Graziano Rossi, Lado Samushia, E. Sánchez, David J. Schlegel, Hee‐Jong Seo, David Sprayberry, G. Tarlé, Michael Walther, Benjamin A. Weaver, Pauline Zarrouk, Cheng Zhao, Rongpu Zhou, Hu Zou · 发表于：Nature Astronomy · 年份：2025 · DOI：10.1038/s41550-025-02669-6 · 被引用次数：55 · 研究领域：Cosmology and Gravitation Theories、Galaxies: Formation, Evolution, Phenomena、Dark Matter and Cosmic Phenomena

Understanding whether cosmic acceleration arises from a cosmological constant or a dynamical component is a central goal of cosmology, and the Dark Energy Spectroscopic Instrument (DESI) enables stringent tests with high-precision distance measurements. Here we analyse measurements of baryon acoustic oscillations in DESI Data Release 1 and Data Release 2 and consider type Ia supernovae and a distance prior for the cosmic microwave background. With the larger statistical power and wider redshift coverage of Data Release 2, the preference for dynamical dark energy does not diminish relative to Data Release 1. Using both a shape-function reconstruction and non-parametric approaches with a Horndeski-motivated correlation prior, we find that the equation of state for dark energy w(z) varies with redshift. Baryon acoustic oscillation data alone yield modest constraints, but in combination with independent supernova compilations and the prior for the cosmic microwave background, they strengthen the evidence for dynamics. A Bayesian comparison of models shows moderate support for departures from Λ cold dark matter (ΛCDM) when several degrees of freedom in w(z) are allowed, corresponding to ~3σ tension with ΛCDM (and higher for some datasets). Despite methodological differences, our results are consistent with companion DESI papers, underscoring the complementarity of the approaches. Possible systematics remain under study; forthcoming DESI, Euclid and next-generation cosmic microwave...