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author Gu, Gan
Wang, Xiaoma
Wang, Yuting
Zhao, Gong-Bo
Pogosian, Levon
Koyama, Kazuya
Peacock, John A.
Cai, Zheng
Cervantes-Cota, Jorge L.
Ishak, Mustapha
Shafieloo, Arman
Zhao, Ruiyang
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cole, Shaun
de la Macorra, Axel
de Mattia, Arnaud
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Hahn, ChangHoon
Howlett, Cullan
Kehoe, Robert
Kirkby, David
Kneib, Jean-Paul
Kremin, Anthony
Lahav, Ofer
Landriau, Martin
Guillou, Laurent Le
Leauthaud, Alexie
Levi, Michael
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Muñoz-Gutiérrez, Andrea
Nadathur, Seshadri
Newman, Jeffrey A.
Palanque-Delabrouille, Nathalie
Percival, Will
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Samushia, Lado
Sanchez, Eusebio
Schlegel, David
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Walther, Michael
Weaver, Benjamin Alan
Zarrouk, Pauline
Zhao, Cheng
Zhou, Rongpu
Zou, Hu
author_facet Gu, Gan
Wang, Xiaoma
Wang, Yuting
Zhao, Gong-Bo
Pogosian, Levon
Koyama, Kazuya
Peacock, John A.
Cai, Zheng
Cervantes-Cota, Jorge L.
Ishak, Mustapha
Shafieloo, Arman
Zhao, Ruiyang
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cole, Shaun
de la Macorra, Axel
de Mattia, Arnaud
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Hahn, ChangHoon
Howlett, Cullan
Kehoe, Robert
Kirkby, David
Kneib, Jean-Paul
Kremin, Anthony
Lahav, Ofer
Landriau, Martin
Guillou, Laurent Le
Leauthaud, Alexie
Levi, Michael
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Muñoz-Gutiérrez, Andrea
Nadathur, Seshadri
Newman, Jeffrey A.
Palanque-Delabrouille, Nathalie
Percival, Will
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Samushia, Lado
Sanchez, Eusebio
Schlegel, David
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Walther, Michael
Weaver, Benjamin Alan
Zarrouk, Pauline
Zhao, Cheng
Zhou, Rongpu
Zou, Hu
contents 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. We analyze baryon acoustic oscillation (BAO) measurements from DESI Data Release 1 (DR1) and Data Release 2 (DR2), combined with Type Ia supernovae and a cosmic microwave background (CMB) distance prior. With the larger statistical power and wider redshift coverage of DR2, the preference for dynamical dark energy does not diminish relative to DR1. Using both a shape-function reconstruction and non-parametric approaches with a Horndeski-motivated correlation prior, we find that the dark-energy equation of state $w(z)$ varies with redshift. BAO data alone yield modest constraints, but in combination with independent supernova compilations and the CMB prior they strengthen the evidence for dynamics. Bayesian model comparison shows moderate support for departures from $Λ$CDM when multiple degrees of freedom in $w(z)$ are allowed, corresponding to $\approx3σ$ tension with $Λ$CDM (and higher for some data sets). Despite methodological differences, our results are consistent with companion DESI papers, underscoring the complementarity of approaches. Possible systematics remain under study; forthcoming DESI, \emph{Euclid}, and next-generation CMB data will provide decisive tests.
format Preprint
id arxiv_https___arxiv_org_abs_2504_06118
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Dynamical Dark Energy in light of the DESI DR2 Baryonic Acoustic Oscillations Measurements
Gu, Gan
Wang, Xiaoma
Wang, Yuting
Zhao, Gong-Bo
Pogosian, Levon
Koyama, Kazuya
Peacock, John A.
Cai, Zheng
Cervantes-Cota, Jorge L.
Ishak, Mustapha
Shafieloo, Arman
Zhao, Ruiyang
Ahlen, Steven
Bianchi, Davide
Brooks, David
Claybaugh, Todd
Cole, Shaun
de la Macorra, Axel
de Mattia, Arnaud
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Hahn, ChangHoon
Howlett, Cullan
Kehoe, Robert
Kirkby, David
Kneib, Jean-Paul
Kremin, Anthony
Lahav, Ofer
Landriau, Martin
Guillou, Laurent Le
Leauthaud, Alexie
Levi, Michael
Manera, Marc
Meisner, Aaron
Miquel, Ramon
Moustakas, John
Muñoz-Gutiérrez, Andrea
Nadathur, Seshadri
Newman, Jeffrey A.
Palanque-Delabrouille, Nathalie
Percival, Will
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Samushia, Lado
Sanchez, Eusebio
Schlegel, David
Seo, Hee-Jong
Sprayberry, David
Tarlé, Gregory
Walther, Michael
Weaver, Benjamin Alan
Zarrouk, Pauline
Zhao, Cheng
Zhou, Rongpu
Zou, Hu
Cosmology and Nongalactic Astrophysics
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. We analyze baryon acoustic oscillation (BAO) measurements from DESI Data Release 1 (DR1) and Data Release 2 (DR2), combined with Type Ia supernovae and a cosmic microwave background (CMB) distance prior. With the larger statistical power and wider redshift coverage of DR2, the preference for dynamical dark energy does not diminish relative to DR1. Using both a shape-function reconstruction and non-parametric approaches with a Horndeski-motivated correlation prior, we find that the dark-energy equation of state $w(z)$ varies with redshift. BAO data alone yield modest constraints, but in combination with independent supernova compilations and the CMB prior they strengthen the evidence for dynamics. Bayesian model comparison shows moderate support for departures from $Λ$CDM when multiple degrees of freedom in $w(z)$ are allowed, corresponding to $\approx3σ$ tension with $Λ$CDM (and higher for some data sets). Despite methodological differences, our results are consistent with companion DESI papers, underscoring the complementarity of approaches. Possible systematics remain under study; forthcoming DESI, \emph{Euclid}, and next-generation CMB data will provide decisive tests.
title Dynamical Dark Energy in light of the DESI DR2 Baryonic Acoustic Oscillations Measurements
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2504.06118