Agripino Sousa-Neto , Carlos Bengaly , Javier E. Gonzalez , Jailson Alcaniz
{"title":"Symbolic regression analysis of dynamical dark energy with DESI-DR2 and SN data","authors":"Agripino Sousa-Neto , Carlos Bengaly , Javier E. Gonzalez , Jailson Alcaniz","doi":"10.1016/j.dark.2025.102108","DOIUrl":null,"url":null,"abstract":"<div><div>Recent measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI DR2), combined with data from the cosmic microwave background (CMB) and Type Ia supernovae (SNe), challenge the <span><math><mi>Λ</mi></math></span>-Cold Dark Matter (<span><math><mi>Λ</mi></math></span>CDM) paradigm. They indicate a potential evolution in the dark energy equation of state (EoS), <span><math><mrow><mi>w</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>, as suggested by analyses that employ parametric models. In this paper, we use a model-independent approach known as high performance symbolic regression (PySR) to reconstruct <span><math><mrow><mi>w</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span> directly from observational data, allowing us to bypass prior assumptions about the underlying cosmological model. Our findings confirm that the DESI DR2 data alone agree with the <span><math><mi>Λ</mi></math></span>CDM model (<span><math><mrow><mi>w</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow><mo>=</mo><mo>−</mo><mn>1</mn></mrow></math></span>) at the redshift range considered. Additionally, when combining DESI data with existing compilations of SN distance measurements, such as Patheon+ and DESY5, we observe no deviation from the <span><math><mi>Λ</mi></math></span>CDM model within <span><math><mrow><mn>3</mn><mi>σ</mi></mrow></math></span> (C.L.) for the interval of values of present-day matter density parameter <span><math><msub><mrow><mi>Ω</mi></mrow><mrow><mi>m</mi></mrow></msub></math></span> and the sound horizon at the drag epoch <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span> currently constrained by observational data. Therefore, similarly to the DESI DR1 case, these results suggest that it is still premature to claim statistically significant evidence for a dynamical EoS or deviations from the <span><math><mi>Λ</mi></math></span>CDM model based on the current DESI data in combination with supernova measurements.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102108"},"PeriodicalIF":6.4000,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics of the Dark Universe","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2212686425003012","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Recent measurements of Baryon Acoustic Oscillations (BAO) from the Dark Energy Spectroscopic Survey (DESI DR2), combined with data from the cosmic microwave background (CMB) and Type Ia supernovae (SNe), challenge the -Cold Dark Matter (CDM) paradigm. They indicate a potential evolution in the dark energy equation of state (EoS), , as suggested by analyses that employ parametric models. In this paper, we use a model-independent approach known as high performance symbolic regression (PySR) to reconstruct directly from observational data, allowing us to bypass prior assumptions about the underlying cosmological model. Our findings confirm that the DESI DR2 data alone agree with the CDM model () at the redshift range considered. Additionally, when combining DESI data with existing compilations of SN distance measurements, such as Patheon+ and DESY5, we observe no deviation from the CDM model within (C.L.) for the interval of values of present-day matter density parameter and the sound horizon at the drag epoch currently constrained by observational data. Therefore, similarly to the DESI DR1 case, these results suggest that it is still premature to claim statistically significant evidence for a dynamical EoS or deviations from the CDM model based on the current DESI data in combination with supernova measurements.
期刊介绍:
Physics of the Dark Universe is an innovative online-only journal that offers rapid publication of peer-reviewed, original research articles considered of high scientific impact.
The journal is focused on the understanding of Dark Matter, Dark Energy, Early Universe, gravitational waves and neutrinos, covering all theoretical, experimental and phenomenological aspects.