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Related papers: On the accelerated expansion of the cosmos

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Strongly lensed type Ia supernovae (SNe Ia) are expected to have some advantages in measuring time delays of multiple images, and so they have a great potential to be developed into a powerful late-universe cosmological probe. In this…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-26 Jing-Zhao Qi , Yu Cui , Wei-Hong Hu , Jing-Fei Zhang , Jing-Lei Cui , Xin Zhang

We find exact solutions in five dimensional inhomogeneous matter dominated model with a varying cosmological constant. Adjusting arbitrary constants of integration one can also achieve acceleration in our model. Aside from an initial…

General Relativity and Quantum Cosmology · Physics 2008-11-26 D. Panigrahi , S. Chatterjee

A measurement of the expansion rate of the Universe (that is the Hubble constant, H0) is derived here using the gamma-ray attenuation observed in the spectra of gamma-ray sources produced by the interaction of extragalactic gamma-ray…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-19 A. Domínguez , F. Prada

In this paper, $F(\nu)$ cosmology is proposed for the accelerating universe with asymptotic de Sitter expansion in terms of Hankel function index $\nu$. To some extent, both the initial expansion during early inflation and the current…

General Relativity and Quantum Cosmology · Physics 2024-02-02 K. Suratgar , M. Mohsenzadeh , E. Yusofi , F. Taghizadeh-Farahmand

Probes of cosmic expansion constitute the main basis for arguments to support or refute a possible apparent acceleration due to different expansion rates in the universe as described by inhomogeneous cosmological models. We present in this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Mustapha Ishak , Austin Peel , M. A. Troxel

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the coincidence and magnitude fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner

Assuming that supernovae type Ia (SNe Ia) are standard candles one could use them to test cosmological theories. The Hubble Space Telescope team analyzed 186 SNe Ia\cite{Riess_04} to test the Standard Cosmological model (SC) associated with…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Alexander F. Zakharov , Victor N. Pervushin

The present rate of the expansion of our Universe, the Hubble constant, can be predicted from the cosmological model using measurements of the early Universe, or more directly measured from the late Universe. But as these measurements…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Adam G. Riess

The possible time variation of the fundamental constants of nature has been an active subject of research in modern physics. In this paper, we propose a new method to investigate such possible time variation of the speed of light $c$ using…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 Yuting Liu , Shuo Cao , Marek Biesiada , Yujie Lian , Xiaolin Liu , Yilong Zhang

We show that detailed exploration of the $1<z<2$ redshift region can provide for definitive testing not only of the standard inflationary cosmological paradigm with its fine-tuned cosmological constant and its mysteriously late ($z<1$)…

Astrophysics · Physics 2009-11-07 Philip D. Mannheim

The most intriguing question of modern astronomy is the question of our Universe formation. The Hubble diagram analysis with Type Ia Supernovae (SNe Ia) is widely used to estimate the cosmological parameters with high accuracy. The…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-14 E. A. Balakina , M. V. Pruzhinskaya

We demonstrate that the high isotropy of the Cosmic Microwave Background (CMB), combined with the Copernican principle, is not sufficient to prove homogeneity of the universe -- in contrast to previous results on this subject. The crucial…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Chris Clarkson , Richard Barrett

We propose and implement a novel, robust, and non-parametric test of statistical isotropy of the expansion of the universe, and apply it to around one thousand type Ia supernovae from the Pantheon sample. We calculate the angular clustering…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-24 John Soltis , Arya Farahi , Dragan Huterer , C. Michael Liberato

Nearly a century after the discovery that we live in an expanding Universe, and two decades after the discovery of accelerating cosmic expansion, there remains no direct detection of this acceleration via redshift drift - a change in the…

Recent studies of Type Ia Supernovae with redshifts up to about $z~\laq~1$ reveal evidence for a cosmic acceleration in the expansion of the Universe. The most straightforward explanation to account for this acceleration is a cosmological…

General Relativity and Quantum Cosmology · Physics 2009-10-31 O. Bertolami , P. J. Martins

The High-Z Supernova Search is an international collaboration to discover and monitor type Ia supernovae (SN Ia) at $z > 0.2$ with the aim of measuring cosmic deceleration and global curvature. Our collaboration has pursued a basic…

We propose a cosmological model which exhibits the phenomenon of self-acceleration: the Universe is attracted to the phase of accelerated expansion at late times even in the absence of the cosmological constant. The self-acceleration is…

High Energy Physics - Theory · Physics 2008-04-15 D. S. Gorbunov , S. M. Sibiryakov

We present empirical evidence extracted directly from the Pantheon Catalog of SNeIa demonstrating that the speed of light varies as the universe expands. Moreover, the speed of light must vary in a specific quantifiable manner. To show…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-10 Hoang Ky Nguyen

The isotropy of the universal Hubble expansion is a fundamental tenet of physical cosmology, but it has not been precisely tested during the current epoch, when dark energy is dominant. Anisotropic expansion will produce a shearing velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Jeremy Darling

The observational evidence for the acceleration of the universe demonstrates that canonical theories of gravitation and particle physics are incomplete, if not incorrect. A new generation of astronomical facilities will shortly be able to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 C. J. A. P. Martins
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