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Related papers: Null test for cosmic curvature using Gaussian proc…

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Although the cosmic curvature has been tightly constrained in the standard cosmological model using observations of cosmic microwave background anisotropies, it is still of great importance to independently measure this key parameter using…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-29 Yan-Jin Wang , Jing-Zhao Qi , Bo Wang , Jing-Fei Zhang , Jing-Lei Cui , Xin Zhang

This paper examines a cosmological model of scale-dependent gravity. The gravitational action is taken to be the Einstein-Hilbert term supplemented with a cosmological constant, where the couplings, $G_k$ and $\Lambda_k$, run with the…

General Relativity and Quantum Cosmology · Physics 2024-05-29 Pedro D. Alvarez , Benjamin Koch , Cristobal Laporte , Angel Rincon

We show how one can test the cosmological Poisson equation by requiring only the validity of three main assumptions: the energy-momentum conservation equations of matter, the equivalence principle, and the cosmological principle. We first…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Ziyang Zheng , Ziad Sakr , Luca Amendola

Applying the distance sum rule in strong gravitational lensing (SGL) and type Ia supernova (SN Ia) observations, one can provide an interesting cosmological model-independent method to determine the cosmic curvature parameter $\Omega_k$. In…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-31 Bo Wang , Jing-Zhao Qi , Jing-Fei Zhang , Xin Zhang

The effect of spatial curvature on primordial perturbations is controlled by $ \Omega_{K,0}/c_{s}^{2} $, where $ \Omega_{K,0} $ is today's fractional density of spatial curvature and $ c_{s} $ is the speed of sound during inflation. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Guus Avis , Sadra Jazayeri , Enrico Pajer , Jakub Supeł

Taking into consideration of a fractal structure for the black hole horizon, Barrow argued that the area law of entropy get modified due to quantum-gravitational effects. Accordingly, the corrected entropy takes the form $S\sim…

General Relativity and Quantum Cosmology · Physics 2023-09-28 Amin Salehi

We test the Yilmaz theory of gravitation by working out the corresponding Friedmann-type equations generated by assuming the Friedmann-Robertson-Walker cosmological metrics. In the case that space is flat the theory is consistent only with…

General Relativity and Quantum Cosmology · Physics 2009-11-13 M. Ibison

The Hubble constant Ho describes not only the expansion of local space at redshift z ~ 0, but is also a fundamental parameter determining the evolution of the universe. Recent measurements of Ho anchored on Cepheid observations have reached…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 C. Henkel , J. A. Braatz , M. J. Reid , J. J. Condon , K. Y. Lo , C. M. V. Impellizzeri , C. Y. Kuo

In this paper, we combine the latest observational data, including the WMAP five-year data (WMAP5), BOOMERanG, CBI, VSA, ACBAR, as well as the Baryon Acoustic Oscillations (BAO) and Type Ia Supernoave (SN) "Union" compilation (307 sample)…

Astrophysics · Physics 2008-11-26 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

In this paper, we present a scheme to investigate the opacity of the Universe in a cosmological-model-independent way, with the combination of current and future available data in gravitational wave (GW) and electromagnetic (EM) domain. In…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-25 Jing-Zhao Qi , Shuo Cao , Yu Pan , Jin Li

In the present work, we apply consistency relation tests to several cosmological models, including the flat and non-flat $\Lambda$CDM models, as well as the flat XCDM model. The analysis uses a non-parametric Gaussian Processes method to…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 J. F. Jesus , A. A. Escobal , R. Valentim , S. H. Pereira

We consider a nonrelativistic cosmological model introduced in [1] and derived as the nonrelativistic limit (or approximation at sub-Hubble scales) of a general relativistic model in [3, 4]. The latter is defined by an energy-momentum…

General Physics · Physics 2017-12-11 Peter C. Stichel

We propose a new and highly model-independent test of cosmic acceleration by comparing observations of the baryon acoustic oscillation (BAO) scale at low and intermediate redshifts: we derive a new inequality relating BAO observables at two…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Will Sutherland

We analyse the clustering of matter on large scales in an extension of the concordance model that allows for spatial curvature. We develop a consistent approach to curvature and wide-angle effects on the galaxy 2-point correlation function…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-04 Julien Bel , Julien Larena , Roy Maartens , Christian Marinoni , Louis Perenon

The theory of inflation provides an elegant explanation for the nearly flat universe observed today, which represents one of the pillars of the standard cosmological model. However, recent studies have reported some deviations from a flat…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-25 Matteo Califano , Rocco D'Agostino , Daniele Vernieri

Following the recent measurement of the acoustic peak by the BOOMERanG and MAXIMA experiments in the CMB anisotropy angular power spectrum, many analyses have found that the geometry of the Universe is very close to flat, but slightly…

Astrophysics · Physics 2009-10-31 Alessandro Melchiorri , Louise M. Griffiths

Cosmic chronometers offer a model-independent way to trace the expansion history of the Universe via the dating of passively evolving objects. This enables testing the validity of cosmological models without concrete assumptions of their…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Carlos A. Álvarez , Marcos M. Cueli , Alessandro Bressan , Lumen Boco , Balakrishna S. Haridasu , Michele Bosi , Luigi Danese , Andrea Lapi

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

Assuming the Central Limit Theorem, experimental uncertainties in any data set are expected to follow the Gaussian distribution with zero mean. We propose an elegant method based on Kolmogorov-Smirnov statistic to test the above; and apply…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-11 Meghendra Singh , Shashikant Gupta , Ashwini Pandey , Satendra Sharma

A Hubble diagram (HD) has recently been constructed in the redshift range 0<z<6.5 using a non-linear relation between the ultraviolet and X-ray luminosities of QSOs. The Type Ia SN HD has already provided a high-precision test of…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 M. Lopez-Corredoira , F. Melia , E. Lusso , G. Risaliti
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