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

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We have developed a technique to systematically discover and study high-redshift supernovae that can be used to measure the cosmological parameters. We report here results based on the initial seven of >28 supernovae discovered to date in…

The difference from 4 to 6 $\sigma$ in the Hubble constant ($H_0$) between the values observed with the local (Cepheids and Supernovae Ia, SNe Ia) and the high-z probes (CMB obtained by the Planck data) still challenges the astrophysics and…

We show that upcoming CMB satellite experiments and large redshift surveys can be used together to yield 5% determinations of H_0 and Omega_m, an order of magnitude improvement over CMB data alone. CMB anisotropies provide the sound horizon…

Astrophysics · Physics 2015-06-24 Daniel J. Eisenstein , Wayne Hu , Max Tegmark

Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Lloyd Knox , Marius Millea

We use measurements of the galaxy-cluster angular size versus redshift to test and compare the standard model (LCDM) and the R_h=ct Universe. We show that the latter fits the data with a reduced chi^2_dof=0.786 for a Hubble constant H_0=…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-25 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

Recently, Sahni, Shafielo o & Starobinsky (2014) combined two independent measurements of $H(z)$ from BAO data with the value of the Hubble constant $H_0 = H(z=0)$, in order to test the cosmological constant hypothesis by means of an…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-21 Xuheng Ding , Marek Biesiada , Shuo Cao , Zhengxiang Li , Zong-Hong Zhu

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…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-01 Maria Giovanna Dainotti , Biagio De Simone , Giovanni Montani , Malgorzata Bogdan

The most recent Hubble constant ($H_0)$ estimates from local methods (z << 1), $H_0=73.8\pm 2.4$ km s$^{-1}$ Mpc$^{-1}$, and the one from high redshifts $H_0=67.3\pm 1.2$ km s$^{-1}$ Mpc$^{-1}$, are discrepant at $2.4 \sigma$ confidence…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 R. F. L. Holanda , V. C. Busti , G. Pordeus da Silva

The geometry of Freedman-Roberston-Walker cosmological models is fixed by the mass density parameter, Omega_M, and the cosmological constant, Omega_Lambda. The classical volume-redshift cosmological relation is a sensitive…

Astrophysics · Physics 2007-05-23 R. G. Carlberg

Direct measurements of Hubble parameters $H(z)$ are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Xiaogang Zheng , Marek Biesiada , Xuheng Ding , Shuo Cao , Sixuan Zhang , Zong-Hong Zhu

The distance-redshift relation depends on the amount of matter of each type in the universe. Measurements at different redshifts constrain differing combinations of these matter densities and thus may be used in combination to constrain…

Astrophysics · Physics 2009-08-18 Martin White

The Hubble constant ($H_0$), which represents the expansion rate of the Universe, is one of the most important cosmological parameters. The recent measurements of $H_0$ using the distance ladder methods such as Type Ia Supernovae (SNe Ia)…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-14 Rahul Kumar Thakur , Shashikant Gupta , Rahul Nigam , PK Thiruvikraman

In the paper, we consider two models in which dark energy is coupled with either dust matter or dark matter, and discuss the conditions that allow more time for structure formation to take place at high redshifts. These models are expected…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-08 Shulei Cao , Tong-Jie Zhang , Xinya Wang , Tingting Zhang

In view of the current and increasing evidence of a running Hubble constant, we investigate its redshift dependence within the flat $\Lambda$CDM framework using a 20-bin analysis of the Master SNe~Ia Sample \citep{2025JHEAp..4800405D},…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-04 Maria Giovanna Dainotti , Avik Banerjee , Andre' LeClair , Giovanni Montani

The tensions between the values of Hubble constant obtained from the early and the late Universe data pose a significant challenge to modern cosmology. Possible modifications of the flat homogeneous isotropic cosmological {\Lambda}CDM model…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-14 S. L. Parnovsky

A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Shuang-Nan Zhang , Yin-Zhe Ma

The determination of the Hubble constant has been a central goal in observational astrophysics for nearly 100 years. Extraordinary progress has occurred in recent years on two fronts: the cosmic distance ladder measurements at low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-14 C. L. Bennett , D. Larson , J. L. Weiland , G. Hinshaw

I investigate through simulations the redshift dependence of several lensing measures for two cosmological models, a flat universe with a cosmological constant (\LambdaCDM), and an open universe (OCDM). I argue that quintessence models can…

Astrophysics · Physics 2007-05-23 Antonio C. C. Guimarães

By relaxing the constraint of adiabatic universe used in most cosmological models, we have shown that the new approach provides a better fit to the supernovae Ia redshift data with a single parameter, the Hubble constant $H_0$, than the…

General Physics · Physics 2018-10-31 Rajendra P. Gupta

The search for a physical model which explains the observed recent acceleration of the universe is a compelling task of modern fundamental cosmology. Recently Fernandes \textit{et al.} presented low redshift observational constraints on a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-01 C. J. A. P. Martins , J. S. J. S. Oliveira , D. A. R. Pinheiro