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A paper by Harmut Traunm\"uller [1] showed from statistical studies of observational data that the most adequate equation to represent observations on magnitude and redshift from 892 type 1a supernovae is $\mu = 5\,log[(1+z)\,ln(1+z)] +…

General Physics · Physics 2018-04-11 Jean-Marie Vigoureux , Dorian Vigoureux , Pierre Vigoureux , Michel Langlois

In this paper we study an anisotropic model generated from a particular Bianchi type-III metric, which is a generalization of G\"odel's metric and an exact solution of Einstein's field equations. We analyse type Ia supernova data, namely…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-02 R. S. Menezes , C. Pigozzo , S. Carneiro

I review the basic theory of the cosmic microwave background anisotropies in adiabatic cold dark matter cosmologies. The latest observational results on the CMB power spectrum are consistent with the simplest inflationary models and…

Astrophysics · Physics 2009-09-25 G. Efstathiou

We perform a model independent reconstruction of the cosmic expansion rate based on type Ia supernova data. Using the Union 2.1 data set, we show that the Hubble parameter behaviour allowed by the data without making any hypothesis about…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 S. Benitez-Herrera , E. E. O. Ishida , M. Maturi , W. Hillebrandt , M. Bartelmann , F. Röpke , .

We use simulated Hubble parameter data in the redshift range 0 \leq z \leq 2 to explore the role and power of observational H(z) data in constraining cosmological parameters of the {\Lambda}CDM model. The error model of the simulated data…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-11 Cong Ma , Tong-Jie Zhang

In this paper, we use three different kinds of observational data, including 130 strong gravitational lensing (SGL) systems, type Ia supernovae (SNeIa: Pantheon and Union2.1) and 31 Hubble parameter data points ($H(z)$) from cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-16 Jing-Wang Diao , Yu Pan , Wenxiao Xu

We present a cosmographic study designed to test the simplest type of accelerating cosmology: a flat universe with matter and a cosmological constant ($\Lambda$). Hubble series expansions are fit to the SCP Union2.1 supernova data set to…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-17 Brett Bochner , Damon Pappas , Menglu Dong

If the Universe is endowed with cosmic anisotropy, it will have a preferred direction of expansion. Reconstructing the expansion history by Gaussian Process (GP) can be used to probe the cosmic anisotropy model-independently. In this paper,…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-25 Zong-Fan Yang , Da-Wei Yao , Ke Wang

We constrain AvERA cosmologies in comparison with the flat $\Lambda$CDM model using cosmic chronometer (CC) data and the Pantheon+ sample of type Ia supernovae (SNe Ia). The analysis includes fits to both CC and SN datasets using the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Adrienn Pataki , Péter Raffai , István Csabai , Gábor Rácz , István Szapudi

By using the Sloan Digital Sky Survey (SDSS) first year type Ia supernova (SN Ia) compilation, we compare two different approaches (traditional \chi^2 and complete likelihood) to determine parameter constraints when the magnitude dispersion…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 B. L. Lago , M. O. Calvão , S. E. Jorás , R. R. R. Reis , I. Waga , R. Giostri

The assumption of homogeneity and isotropy on large scales is one of the main hypotheses of the standard cosmological model. In this paper, we revisit a test of cosmological isotropy using type Ia supernova (SN Ia) distances provided by the…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-01 Uendert Andrade , Carlos A. P. Bengaly , Beethoven Santos , Jailson S. Alcaniz

The latest improvements in the scale and calibration of Type Ia supernovae catalogues allow us to constrain the specific nature and evolution of dark energy through its effect on the expansion history of the universe. We present the results…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-05 Toby Lovick , Suhail Dhawan , Will Handley

We explore the possible advantages of extending the $\Lambda$CDM model by more realistic backgrounds compared to its spatially flat RW spacetime assumption, while preserving the underpinning physics; in particular, by simultaneously…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-05 Ozgur Akarsu , Eleonora Di Valentino , Suresh Kumar , Maya Ozyigit , Shivani Sharma

We analyze two volume limited galaxy samples from the SDSS photometric and spectroscopic data to test the isotropy in the local Universe. We use information entropy to quantify the global anisotropy in the galaxy distribution at different…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Suman Sarkar , Biswajit Pandey , Rishi Khatri

Cosmic Microwave Background (CMB) independent approaches are frequently used in the literature to provide estimates of Hubble constant ($H_0$). In this work, we report CMB independent constraints on $H_0$ in an anisotropic extension of…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-13 Vikrant Yadav

We probe the possible anisotropy of the Universe by using the JLA compilation of type-Ia supernovae. We apply the Markov Chain Monte Carlo (MCMC) method to constrain the amplitude and direction of anisotropy in three cosmological models.…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-29 Hai-Nan Lin , Sai Wang , Zhe Chang , Xin Li

In this work, a computer optimization model has been developed that allows one to load the initial observation data of supernovae 1a into a table and, simply, by searching for the best fit between observations and theory, obtain the values…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-02 A. P. Mahtessian , G. S. Karapetian , M. A. Hovhannisyan , L. A. Mahtessian

When Type Ia supernovae are used to infer cosmological parameters, their luminosities are compared to those from a homogeneous cosmology. In this note we propose a test to examine to what degree SN Ia have been observed on lines of sight…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-01 Paul Shah , Pablo Lemos , Ofer Lahav

The $\Lambda$CDM cosmological model provides to first approximation a good description of the universe, but various tensions with data, most notably Hubble tension, persist. In this work we confront $\Lambda$CDM with the Pantheon Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 Eoin Ó Colgáin

Type Ia supernovae (SNIa) play a central role in constraining the late-time expansion history of the Universe and are directly implicated in current cosmological tensions. Motivated by the possibility of unaccounted redshift-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Seyed Hamidreza Mirpoorian , Meng-Xiang Lin , Levon Pogosian