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Related papers: Putting Flat $\Lambda$CDM In The (Redshift) Bin

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The CMB is already one of the pillars of the Big Bang model. However it may also become our most powerful tool to distinguish contending models and to determine their cosmological parameters. To realize this goal, more than 20 observational…

Astrophysics · Physics 2007-05-23 Charles H. Lineweaver

We use 32 age measurements of passively evolving galaxies as a function of redshift to test and compare the standard model ($\Lambda$CDM) with the $R_{\rm h}=ct$ Universe. We show that the latter fits the data with a reduced $\chi^2_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia , Fa-Yin Wang , Hai Yu

Magnitude predictions of $\Lambda$CDM, as parametrized by the Planck collaboration, are not consistent with the supernova data of the whole Pantheon+ sample even when, in order to take into account the uncertainty about its value, the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yves-Henri Sanejouand

The standard cosmological model, LCDM, provides an excellent fit to Cosmic Microwave Background (CMB) data. However, the model has well known problems. For example, the cosmological constant, is fine-tuned to 1 part in 10^100 and the cold…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 T. Shanks , R. W. F. Johnson , J. A. Schewtschenko , J. R. Whitbourn

In this paper, we propose a new parametrization of $Om(z)$ diagnostics and show how the most recent and significantly improved observations concerning the $H(z)$ and SN Ia measurements can be used to probe the consistency or tension between…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Jing-Zhao Qi , Shuo Cao , Marek Biesiada , Tengpeng Xu , Yan Wu , Sixuan Zhang , Zong-Hong Zhu

We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

We use a combination of the most recent cosmic microwave background (CMB) flat -band power measurements to place constraints on Hubble's constant h and the total density of the Universe Omega_o in the context of inflation-based cold dark…

Astrophysics · Physics 2009-10-30 Charles H. Lineweaver , Domingos Barbosa

Recent measurements of the parameters of the Concordance Cosmology Model ($\Lambda$CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done with Cosmic Microwave Background (CMB) imply different…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 B. Czerny , M. L. Martínez-Aldama , G. Wojtkowska , M. Zajaček , P. Marziani , D. Dultzin , M. H. Naddaf , S. Panda , R. Prince , R. Przyluski , M. Ralowski , M. Śniegowska

The cosmographic approach is gaining considerable interest as a model-independent technique able to describe the late expansion of the universe. Indeed, given only the observational assumption of the cosmological principle, it allows to…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 Micol Benetti , Salvatore Capozziello

Local determinations of the Hubble constant $H_0$ favour a higher value than Planck based on CMB and $\Lambda$CDM. Through a model-independent expansion, we show that low redshift ($z \lesssim 0.7$) data comprising baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Aritra Banerjee , Haiying Cai , Lavinia Heisenberg , Eoin Ó Colgáin , M. M. Sheikh-Jabbari , Tao Yang

Cosmological models and their parameters are widely debated because of theoretical and observational mismatches of the standard cosmological model, especially the current discrepancy between the value of the Hubble constant, $H_{0}$,…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-31 Aleksander Łukasz Lenart , Giada Bargiacchi , Maria Giovanna Dainotti , Shigehiro Nagataki , Salvatore Capozziello

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

General Relativity and Quantum Cosmology · Physics 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

The Dark Energy Spectroscopic Instrument (DESI) collaboration recently released the first year data of baryon acoustic oscillations (BAOs). Based on the five different tracers, the cosmological constraint shows a hint of deviation from the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-16 X. D. Jia , J. P. Hu , S. X. Yi , F. Y. Wang

For a broad range of parameter values, braneworld models display a remarkable property which we call cosmic mimicry. Cosmic mimicry is characterized by the fact that, at low redshifts, the Hubble parameter in the braneworld model is…

Astrophysics · Physics 2009-11-11 Varun Sahni , Yuri Shtanov , Alexander Viznyuk

Cosmological parameters are constrained by a wide variety of observations. We examine the concordance diagram for modern measurements of the Hubble constant, the shape parameter from large scale structure, the cluster baryon fraction, and…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-22 Stacy McGaugh

We present a joint analysis of the Planck cosmic microwave background (CMB) and Baryon Oscillation Spectroscopic Survey (BOSS) final data releases. A key novelty of our study is the use of a new full-shape (FS) likelihood for the…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Mikhail M. Ivanov , Marko Simonović , Matias Zaldarriaga

We report on measurements of the cosmological constant, Lambda, and the redshift space distortion parameter beta=Omega_m^0.6/b, based on an analysis of the QSO power spectrum parallel and perpendicular to the observer's line of sight, from…

Astrophysics · Physics 2009-11-10 P. J. Outram , T. Shanks , B. J. Boyle , S. M. Croom , Fiona Hoyle , N. S. Loaring , L. Miller , R. J. Smith

Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-19 Brett Bochner , Aiden Jin

The standard model of cosmology LCDM assumes general relativity, flat space, and the presence of a positive cosmological constant. We relax these assumptions allowing spatial curvature, time-dependent effective dark energy equation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Lucas Lombriser

Hubble tension is a problem in one-dimensional (1D) posteriors, since local $H_0$ determinations are only sensitive to a single parameter. Projected 1D posteriors for $\Lambda$CDM cosmological parameters become more non-Gaussian with…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-06 Eoin Ó Colgáin , Saeed Pourojaghi , M. M. Sheikh-Jabbari , Darragh Sherwin