The use of the baryonic acoustic oscillations (BAO) datasets offers a unique opportunity to connect the early universe and the late one. In this proceeding, we discuss recent results that used a marginalised likelihood to remove the $H_0-r_d $ degeneracy and then tested it on different dark energy (DE) models. It was found that this approach which does not rely on calibration on $r_d$ or $H_0$, allows us to obtain results, comparable to the ones calculated with standard likelihoods. Here we emphasize on the major differences that we observed for the two different BAO datasets that we employed -- a transversal one, containing only angular BAO measurements, and a mixed one, containing both angular and radial BAO measurements. We see that the two datasets have different statistical preferences for DE models and also different preference for the curvature of the universe.
A New Consistency Test for the $Λ$CDM Model using Radial and Transverse BAO Measurements
The International Division of the Second High School Attached to Beijing Normal University(北京师范大学第二附属中学国际部);Department of Astronomy, Tsinghua University(清华大学天文系)
Revisiting the equation of state of dark energy from DESI BAO with SNe Ia and CMB
Institute for Gravitational Wave Astronomy, Henan Academy of Sciences(河南科学院引力波天文研究院);School of Microelectronics, Qingdao University of Science and Technology(青岛科技大学微电子学院)
本文结合DESI BAO DR2、Pantheon+ SNe Ia与Planck 2018 CMB数据,采用红移截断策略分析w0waCDM模型,发现z~0.4-0.8数据会致约2σ偏差,无可靠证据支持其优于ΛCDM模型,偏差或源于统计波动与子样本局限。
Constraints on $H_0$ from WMAP and baryon acoustic osillation measurements
本文报道了由威尔金森微波各向异性探测器(WMAP)结合最新的重子声学振荡(BAO)测量得到的PDMATHAMM的约束条件。我们使用6dF星系巡天(6dFGS),SDSS DR 7主星系样本(MGS),BOSS DR 12星系和eBOSS DR 14类星体的BAO测量。在WMAP宇宙微波背景辐射(CMB)数据中加入最近的BAO观测数据,我们将宇宙学参数$Ω_m=0.298\pm0.005$,$H_0=68.36^{+0.53}_{-0.52}$ km s $^{-1}$ Mpc $^{-1}$,$σ_8=0.8170^{+0.0159}_{-0.0175}$分别约束在空间平坦的$Λ$冷暗物质(CDM)模型中,将$Ω_m=0.302\pm0.008$,$H_0=67.63\pm1.30$ km s $^{-1}$ Mpc $^{-1}$,$σ_8=0.7988^{+0.0345}_{-0.0338}$约束在空间平坦的$w$ CDM模型中.在空间平坦的$w$ CDM模型中,来自CMB和BAO的对$w$的组合约束是$w=-0.96\pm0.07$。我们测量的$H_0$结果更倾向于低于70 km s的$^{-1}$ Mpc $^{-1}$值,与普朗克(2018)关于CMB约束的最新数据一致,但与Riess等人(2018)的局部测量结果存在$3.1\sim 3.5σ$张力。与WMAP单独分析相…
Elucidating $Λ$CDM: Impact of Baryon Acoustic Oscillation Measurements on the Hubble Constant Discrepancy
我们研究了重子声振荡(BAO)尺度测量的影响之间的差异的哈勃常数($H_0$)推断从本地距离阶梯和普朗克宇宙微波背景(CMB)数据。虽然单独的BAO数据不能约束$H_0$,但我们表明,将最新的BAO结果与WMAP,Atacama宇宙学望远镜(ACT)或南极望远镜(SPT)CMB数据相结合,产生的$H_0$值$2.4-3.1σ$低于距离阶梯,独立于普朗克,这种向下的拉力在一些早期的分析中不太明显,这些分析只使用了角度,平均BAO尺度约束,而不是完整的各向异性信息。同时,BAO和CMB数据的组合也不利于普朗克高多极温度功率谱所偏好的较低的$H_0$值。结合银河系和Lyman-$α$森林(Ly $α$)BAO与原始氘丰度的精确估计,得到了平坦$Λ$ CDM模型的$H_0=66.98\pm1.18$ km s $^{-1}$ Mpc $^{-1}$.这个值是完全独立的CMB各向异性的约束,是$3.0σ$低于最新的距离阶梯约束,虽然$2.4σ$张力也存在于星系BAO和LY $α$ BAO之间。这些结果表明,这是不可能的解释$H_0$的分歧,仅与普朗克数据的系统误差。事实上,即使在删除任何一个数据集之后,紧张局势仍然存在,这使得这个有趣的难题更加难以解决。
Probing dynamical dark energy with late-time data: Evidence, tensions, and the limits of the $w_0w_a$CDM framework
School of Physics and Astronomy, Sun Yat-Sen University(中山大学物理与天文学院);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);Plaksha University(普拉克斯哈大学);College of Astronomy and Space Sciences, University of Chinese Academy of Sciences(中国科学院大学天文学与空间科学学院);Graduate Program in Applied Physics, Federal University of Latin-American Integration(拉丁美洲联邦大学应用物理研究生项目);Departamento de Engenharias e Ciências Exatas, Universidade Federal do Paraná(巴拉那联邦大学工程与自然科学系);Department of Physics, Istanbul Technical University(伊斯坦布尔理工大学物理系)
本文通过结合CMB各向异性、DESI DR2、SDSS-IV、横向/角BAO(BAOtr)和Ia型超新星数据,测试$w_0w_a$CDM(CPL)框架与$Λ$CDM的差异,发现CPL推断依赖于数据集,CMB数据单独使用存在几何退化,而DESI DR2 BAO数据推动重建向弱现今加速发展,相比之下,CMB结合PP\&SH0ES和BAOtr更倾向于中等加速膨胀并显著减少哈勃矛盾。这种行为源于低红移距离信息:BAOtr和DESI/SDSS在$z\lesssim0.5$时偏好不同的BAO距离比,驱动了不同的CPL膨胀历史。通过比较角BAO尺度,包括共同的$z=0.510$点和保守的BAOtr局部插值(无外推),量化了这种不匹配。在CPL中,预重组物理固定,$r_{ m d}$几乎不变,因此$H_0$的变化被晚期膨胀自由度吸收而非声学 horizon的变化。贝叶斯证据同样依赖于低红移数据:当PP\&SH0ES和/或BAOtr包含时,它倾向于CPL,对于CMB单独或CMB+DESI是不确定的,而对于CMB+SDSS则略微倾向于$Λ$CDM。这些结果表明,CPL的明显支持及其缓解哈勃矛盾的能力并非普遍,这促使了更灵活的晚期模型和对BAO系统误差的更仔细审查。
Comparing measures of the Hubble and BAO tensions in $Λ$CDM and possible solutions in $f(Q)$ gravity
Institute of Cosmology & Gravitation, University of Portsmouth(朴茨茅斯大学宇宙学与引力研究所);Scottish Universities Physics Alliance, University of Saint Andrews(圣安德鲁斯大学苏格兰大学物理联盟)
The Role of Big Bang Nucleosynthesis in Joint Cosmological Analyses
Boston University(波士顿大学);University of California, Santa Barbara(加州大学圣塔芭芭拉分校);Lawrence Berkeley National Laboratory(劳伦斯伯克利国家实验室);University of California, Berkeley(加州大学伯克利分校)
Atlantic Technological University(大西洋科技大学);School of Physics, Institute for Research in Fundamental Sciences (IPM)(基础科学研究所物理学院);Department of Physics, Shanghai University(上海大学物理系)
BAO miscalibration cannot rescue late-time solutions to the Hubble tension
University of Trento(特伦托大学);Trento Institute for Fundamental Physics and Applications (TIFPA)-INFN(特伦托基础物理与应用研究所(TIFPA)-意大利国家核物理研究所);Istanbul Technical University(伊斯坦布尔技术大学);University of Sheffield(谢菲尔德大学);Universidade Federal do Espírito Santo(圣埃斯皮里图联邦大学);INAF – Osservatorio Astronomico di Trieste(意大利国家天体物理研究所的里雅斯特天文台);IFPU – Institute for Fundamental Physics of the Universe(宇宙基础物理研究所);University of Ioannina(约阿尼纳大学)
Dark Energy Survey: DESI-Independent Angular BAO Measurement
Université Grenoble Alpes, CNRS, LPSC-IN2P3(格勒诺布尔阿尔卑斯大学);Aix Marseille Univ, CNRS/IN2P3, CPPM(艾克斯马赛大学);Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)(能源、环境和技术研究中心);Ruhr University Bochum(波鸿鲁尔大学);Brookhaven National Laboratory(布鲁克海文国家实验室);Laboratório Interinstitucional de e-Astronomia - LIneA(跨机构电子天文学实验室);Department of Physics, University of Cincinnati(辛辛那提大学物理系);Perimeter Institute for Theoretical Physics(理论物理前沿研究所);Center for Astrophysical Surveys, National Center for Supercomputing Applications(国家超级计算应用中心天体物理调查中心)