Investigating the Hubble Constant Tension: Two Numbers in the Standard Cosmological Model

Abstract We address the $$\simeq 4.4\sigma $$≃4.4σ tension between local and the CMB measurements of the Hubble Constant using simulated Type Ia Supernova (SN) data-sets. We probe its directional dependence by means of a hemispherical comparison through the entire celestial sphere as an estimator of the $$H_0$$H0 cosmic variance. We perform Monte Carlo simulations assuming isotropic and non-uniform distributions of data points, the latter coinciding with the real data. This allows us to incorporate observational features, such as the sample incompleteness, in our estimation. We obtain that this tension can be alleviated to $$3.4\sigma $$3.4σ for isotropic realizations, and $$2.7\sigma $$2.7σ for non-uniform ones. We also find that the $$H_0$$H0 variance is largely reduced if the data-sets are augmented to 4 and 10 times the current size. Future surveys will be able to tell whether the Hubble Constant tension happens due to unaccounted cosmic variance, or whether it is an actual indication of physics beyond the standard cosmological model.

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A Measurement of the Hubble Constant by the Megamaser Cosmology Project

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317010249 ◽

2017 ◽

Vol 13 (S336) ◽

pp. 86-91 ◽

Cited By ~ 1

Author(s):

James Braatz ◽

James Condon ◽

Christian Henkel ◽

Jenny Greene ◽

Fred Lo ◽

...

Keyword(s):

Dark Energy ◽

Cosmological Model ◽

Hubble Constant ◽

Final Analysis ◽

Direct Test ◽

Microwave Background ◽

Distance Measurements ◽

Standard Cosmological Model ◽

Geometric Measurement ◽

Hubble Flow

AbstractThe Megamaser Cosmology Project (MCP) measures the Hubble Constant by determining geometric distances to circumnuclear 22 GHz H2O megamasers in galaxies at low redshift (z < 0.05) but well into the Hubble flow. In combination with the recent, exquisite observations of the Cosmic Microwave Background by WMAP and Planck, these measurements provide a direct test of the standard cosmological model and constrain the equation of state of dark energy. The MCP is a multi-year project that has recently completed observations and is currently working on final analysis. Based on distance measurements to the first four published megamasers in the sample, the MCP currently determines H0 = 69.3 ± 4.2 km s−1 Mpc−1. The project is finalizing analysis for five additional galaxies. When complete, we expect to achieve a ~4% measurement. Given the tension between the Planck prediction of H0 in the context of the standard cosmological model and astrophysical measurements based on standard candles, the MCP provides a critical and independent geometric measurement that does not rely on external calibrations or a distance ladder.

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A hybrid model of viscous and Chaplygin gas to tackle the Universe acceleration

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09104-w ◽

2021 ◽

Vol 81 (4) ◽

Author(s):

A. Hernández-Almada ◽

Miguel A. García-Aspeitia ◽

M. A. Rodríguez-Meza ◽

V. Motta

Keyword(s):

Cosmological Model ◽

Hybrid Model ◽

Hubble Constant ◽

Chaplygin Gas ◽

Joint Analysis ◽

Acoustic Oscillations ◽

Generalized Chaplygin Gas ◽

Om Diagnostic ◽

Standard Cosmological Model ◽

The Universe

AbstractMotivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a viscous generalized Chaplygin gas (VGCG) and its free parameters are constrained through several cosmological data like the Observational Hubble Parameter, Type Ia Supernovae, Baryon Acoustic Oscillations, Strong Lensing Systems, HII Galaxies and using Joint Bayesian analysis. In addition, we implement a Om-diagnostic to analyze the VGCC dynamics and its difference with the standard cosmological model. The hybrid model shows important differences when compared with the standard cosmological model. Finally, based on our Joint analysis we find that the VGCG could be an interesting candidate to alleviate the well-known Hubble constant tension.

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FUGACITY AND REHEATING OF PRIMORDIAL NEUTRINOS

Modern Physics Letters A ◽

10.1142/s0217732313501885 ◽

2013 ◽

Vol 28 (40) ◽

pp. 1350188 ◽

Cited By ~ 2

Author(s):

JEREMIAH BIRRELL ◽

CHENG-TAO YANG ◽

PISIN CHEN ◽

JOHANN RAFELSKI

Keyword(s):

Cosmological Model ◽

Background Radiation ◽

Chemical Nonequilibrium ◽

Model Parameter ◽

Standard Cosmological Model ◽

Cmb Fluctuations ◽

The Impact ◽

Freeze Out

We clarify in a quantitative way the impact that distinct chemical Tc and kinetic Tk freeze-out temperatures have on the reduction of the neutrino fugacity ϒν below equilibrium, i.e. ϒν<1, and the increase of the neutrino temperature Tν via partial reheating. We establish the connection between ϒν and Tk via the modified reheating relation Tν(ϒν)/Tγ, where Tγ is the temperature of the background radiation. Our results demonstrate that one must introduce the chemical nonequilibrium parameter, i.e. the fugacity, ϒν, as an additional standard cosmological model parameter in the evaluation of CMB fluctuations as its value allows measurement of Tk.

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A CRITIQUE OF THE STANDARD COSMOLOGICAL MODEL : TUTORIAL

Neural Network World ◽

10.14311/nnw.2014.24.026 ◽

2014 ◽

Vol 24 (5) ◽

pp. 435-461 ◽

Cited By ~ 3

Author(s):

Michal Křížek ◽

Lawrence Somer

Keyword(s):

Cosmological Model ◽

Standard Cosmological Model

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O UNIVERSO VIVO

Revista da Universidade Federal de Minas Gerais ◽

10.35699/2316-770x.2012.2718 ◽

2012 ◽

Vol 19 (1.2) ◽

Cited By ~ 7

Author(s):

Francisco César de Sá Barreto ◽

Luiz Paulo Ribeiro Vaz ◽

Gabriel Armando Pellegatti Franco

Keyword(s):

Cosmological Model ◽

Chemical Elements ◽

Big Bang ◽

Living System ◽

Irreversible Processes ◽

Thermodynamics Of Irreversible Processes ◽

Protons And Neutrons ◽

Standard Cosmological Model ◽

The Big Bang ◽

The Universe

The standard cosmological model suggests that after the “Big Bang”, 14 billion of years ago, the universe entered a period of expansion and cooling. In the first one millionth of a second appear quarks, glúons, electrons and neutrinos, followed by the appearance of protons and neutrons. In this paper, we describe the “cosmic battle” between gravitation and energy, responsible for the lighter chemical elements and the formation of the stars. We describe the thermodynamics of irreversible processes of systems which are far away from equilibrium, a route that is followed by the universe, seen as a living system.

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The Perturbation of Material Density in f(R) Modified Gravity of Polynormal Exponential Form

10.29007/xqpk ◽

2020 ◽

Author(s):

Van On Vo

Keyword(s):

Cosmological Model ◽

Modified Gravity ◽

Linear Perturbation ◽

Exponential Form ◽

Material Density ◽

Gravitational Model ◽

Standard Cosmological Model ◽

The Difference ◽

Evolutionary Aspects ◽

The Universe

In this paper, we investigate the linear perturbation of the material density of the universe in f(R) modified gravity of polynomial exponential form on the scale of distance below the cosmic horizon (sub-horizon). The results show that the model for the evolutionary aspects of the universe is slightly different from that in the standard cosmological model of ΛCDM. They can be used to show the difference between this modified gravitational model with the standard cosmological model of ΛCMD and other cosmological models. We also investigate the ration Ψ/ Φ and Geff / GN in the model and show that they are within allowable limits of experiments.

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