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相关论文: A tale of two (or more) $h$'s

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We investigate an extension of $\Lambda$CDM in which a fraction of cold Dark Matter (DM) decays into invisible dark radiation (DR) around the radiation-matter equality epoch, together with a non-standard dark energy (DE) equation of state…

宇宙学与河外天体物理 · 物理学 2026-05-26 Rahul Dhyani , Purba Mukherjee , Arindam Chatterjee , Anjan A Sen

We present cosmological results from the final galaxy clustering data set of the Baryon Oscillation Spectroscopic Survey, part of the Sloan Digital Sky Survey III. Our combined galaxy sample comprises 1.2 million massive galaxies over an…

The Effective Field Theory of Large-Scale Structure (EFTofLSS) is a formalism that allows us to predict the clustering of Cosmological Large-Scale Structure in the mildly non-linear regime in an accurate and reliable way. After validating…

Low amplitude (linear regime) cosmic density fluctuations lead to spatial variations in the locally measurable value of $H_0$ (denoted as $H_L$), $\delta_H \equiv (H_L-H_0)/H_0$, which are of order 3-6% (95% confidence interval) in a sphere…

天体物理学 · 物理学 2009-10-30 Yun Wang , David N. Spergel , Edwin L. Turner

We present a new method for consistent, joint analysis of the pre- and post-reconstruction two-point functions of the BOSS survey. The post-reconstruction correlation function is used to accurately measure the distance-redshift relation and…

宇宙学与河外天体物理 · 物理学 2022-02-09 Shi-Fan Chen , Zvonimir Vlah , Martin White

Local measurements of the Hubble constant ($H_0$) based on Cepheids e Type Ia supernova differ by $\approx 5 \sigma$ from the estimated value of $H_0$ from Planck CMB observations under $\Lambda$CDM assumptions. In order to better…

宇宙学与河外天体物理 · 物理学 2023-07-07 Carlos Bengaly , Maria Aldinez Dantas , Luciano Casarini , Jailson Alcaniz

We present a simple and promising new method to measure the expansion rate and the geometry of the universe that combines observations related to the time delays between the multiple images of time-varying sources, strongly lensed by galaxy…

宇宙学与河外天体物理 · 物理学 2024-02-06 A. Acebron , S. Schuldt , C. Grillo , P. Bergamini , G. Granata , U. Mestric , G. B. Caminha , M. Meneghetti , A. Mercurio , P. Rosati , S. H. Suyu , E. Vanzella

We present a novel approach to measuring the expansion rate and the geometry of the Universe, which combine time-delay cosmography in lens galaxy clusters with pure samples of 'cosmic chronometers' (CCs) by probing the member galaxies. The…

宇宙学与河外天体物理 · 物理学 2024-01-11 P. Bergamini , S. Schuldt , A. Acebron , C. Grillo , U. Mestric , G. Granata , G. B. Caminha , M. Meneghetti , A. Mercurio , P. Rosati , S. H. Suyu , E. Vanzella

Whereas many measurements in cosmology depend on the use of integrated distances or time, galaxies evolving passively on a time scale much longer than their age difference allow us to determine the expansion rate H(z) solely as a function…

宇宙学与河外天体物理 · 物理学 2018-09-21 Jun-Jie Wei , Fulvio Melia , Xue-Feng Wu

Gravitational waves (GWs) from the inspiral of binary compact objects offer a one-step measurement of the luminosity distance to the event, which is essential for the measurement of the Hubble constant, $H_0$, which characterizes the…

宇宙学与河外天体物理 · 物理学 2025-03-10 Tathagata Ghosh , Surhud More , Sayantani Bera , Sukanta Bose

Estimates of $H_0$ from Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness of galaxy clusters depends on the underlying cosmology. In the current $\Lambda$CDM flat cosmology, a possible technique to broke the degenerescency on the…

天体物理学 · 物理学 2008-11-26 J. V. Cunha , L. Marassi , J. A. S. Lima

We perform a joint determination of the distance-redshift relation and cosmic expansion rate at redshifts z = 0.44, 0.6 and 0.73 by combining measurements of the baryon acoustic peak and Alcock-Paczynski distortion from galaxy clustering in…

Cosmic microwave background measurements have pushed to higher resolution, lower noise, and more sky coverage. These data enable a unique test of the early universe's expansion rate and constituents such as effective number of relativistic…

宇宙学与河外天体物理 · 物理学 2013-08-05 Alireza Hojjati , Eric V. Linder , Johan Samsing

The standard cosmological model, the $\Lambda$CDM model, is the most suitable description for our universe. This framework can explain the accelerated expansion phase of the universe but still is not immune to open problems when it comes to…

宇宙学与河外天体物理 · 物理学 2024-01-01 Maria Giovanna Dainotti , Biagio De Simone , Giovanni Montani , Malgorzata Bogdan

This thesis presents the analysis of the clustering of galaxies in the 6dF Galaxy Survey (6dFGS). At large separation scales the baryon acoustic oscillation (BAO) signal is detected which allows to make an absolute distance measurement at…

宇宙学与河外天体物理 · 物理学 2013-03-15 Florian Beutler

The canonical $\Lambda$CDM cosmological model makes precise predictions for the clustering and lensing properties of galaxies. It has been shown that the lensing amplitude of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) is…

宇宙学与河外天体物理 · 物理学 2021-02-03 Johannes U. Lange , Alexie Leauthaud , Sukhdeep Singh , Hong Guo , Rongpu Zhou , Tristan L. Smith , Francis-Yan Cyr-Racine

The $\Lambda$CDM model faces several tensions with recent cosmological data and their increased accuracy. The mismatch between the values of the Hubble constant $H_0$ obtained from direct distance ladder measurements and from the cosmic…

宇宙学与河外天体物理 · 物理学 2024-05-03 Alain Blanchard , Jean-Yves Héloret , Stéphane Ilić , Brahim Lamine , Isaac Tutusaus

We compare a large suite of theoretical cosmological models to observational data from the cosmic microwave background, baryon acoustic oscillation measurements of expansion, Type Ia SNe measurements of expansion, redshift space distortion…

宇宙学与河外天体物理 · 物理学 2017-12-13 Zhongxu Zhai , Michael Blanton , Anže Slosar , Jeremy Tinker

The Hubble tension is commonly framed as a discrepancy between local, late-time measurements favoring $H_0 \approx 73$ km s$^{-1}$ Mpc$^{-1}$ and early-time, Sound-Horizon-based measurements favoring $H_0 \approx 67$ km s$^{-1}$ Mpc$^{-1}$.…

宇宙学与河外天体物理 · 物理学 2026-01-27 Ioannis Pantos , Leandros Perivolaropoulos