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Related papers: Consistency of Pantheon+ supernovae with a large-s…

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In this paper, we study the anisotropy of cosmic acceleration the using Pantheon sample, which includes 1048 spectroscopically confirmed Type Ia supernovae (SNe Ia) covering the redshift range $0.01 < z < 2.3$. In hemisphere comparison…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-05 Z. Q. Sun , F. Y. Wang

We employ the hemisphere comparison (HC) method and the dipole fitting (DF) method to investigate the cosmic anisotropy in the recently released Pantheon sample of type Ia supernovae (SNe Ia) and five combinations among Pantheon. For the HC…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-21 Dong Zhao , Yong Zhou , Zhe Chang

We employ Maximum Likelihood Estimators to examine the Pantheon+ catalogue of Type Ia supernovae for large scale anisotropies in the expansion rate of the Universe. The analyses are carried out in the heliocentric frame, the CMB frame, as…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-02 Animesh Sah , Mohamed Rameez , Subir Sarkar , Christos Tsagas

We test the possible dipole anisotropy of a Finslerian cosmological model and other three dipole-modulated cosmological models, i.e., the dipole-modulated $\rm{\Lambda}$CDM, $w$CDM and Chevallier--Polarski--Linder (CPL) model by using the…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Zhe Chang , Dong Zhao , Yong Zhou

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

Magnitude predictions of $\Lambda$CDM, as parametrized by the Planck collaboration, are not consistent with the supernova data of the whole Pantheon+ sample even when, in order to take into account the uncertainty about its value, the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Yves-Henri Sanejouand

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

We present a hemispherical comparison analysis of the deceleration parameter $q_0$ using the Pantheon+ sample of Type Ia supernovae to test the isotropy of cosmic acceleration and the robustness of redshift corrections. We detect…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-06 Mauricio Lopez-Hernandez , Josue De-Santiago

The cosmological principle assumes that the universe is homogeneous and isotropic on cosmic scales. There exist many works testing the cosmic homogeneity and/or the cosmic isotropy of the universe in the literature. In fact, some…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Hua-Kai Deng , Hao Wei

We present a model-independent test of anisotropy in the cosmic distance duality relation (CDDR), $D_L=(1+z)^2 D_A$, using the Pantheon+ type Ia supernova sample and baryon acoustic oscillation (BAO) data. The angular diameter distance is…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-07 Pushty Shrimankar , Gopal Kashyap

A 10\% difference in the scale for the Hubble parameter constitutes a clear problem for cosmology. Here, considering angular distribution of Type Ia supernovae (SN) within the Pantheon compilation and working within flat $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 Chethan Krishnan , Roya Mohayaee , Eoin Ó Colgáin , M. M. Sheikh-Jabbari , Lu Yin

We analyze the magnitude-redshift data of type Ia supernovae included in the Union and Union2 compilations in the framework of an anisotropic Bianchi type I cosmological model and in the presence of a dark energy fluid with anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 L. Campanelli , P. Cea , G. L. Fogli , A. Marrone

The assumption of isotropy -- that the Universe looks the same in all directions on large scales -- is fundamental to the standard cosmological model. This model forms the building blocks of essentially all of our cosmological knowledge to…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-29 Jessica A. Cowell , Suhail Dhawan , Hayley J. Macpherson

We probe the isotropy of the Universe with the largest all-sky photometric redshift dataset currently available, namely WISE~$\times$~SuperCOSMOS. We search for dipole anisotropy of galaxy number counts in multiple redshift shells within…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 C. A. P. Bengaly , C. P. Novaes , H. S. Xavier , M. Bilicki , A. Bernui , J. S. Alcaniz

The standard cosmology strongly relies upon the Cosmological Principle, which consists on the hypotheses of large scale isotropy and homogeneity of the Universe. Testing these assumptions is, therefore, crucial to determining if there are…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-27 U. Andrade , C. A. P. Bengaly , J. S. Alcaniz , B. Santos

The cosmological principle assumes the isotropy of the Universe at large scales. It is a foundational assumption in the $\Lambda$CDM model, which is the current standard model of cosmology. Recent tensions give legitimacy to investigating…

Observations reveal a `bulk flow' in the local Universe which is faster and extends to much larger scales than is expected around a typical observer in the standard $\Lambda$CDM cosmology. This is expected to result in a scale-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 Jacques Colin , Roya Mohayaee , Mohamed Rameez , Subir Sarkar

We test the isotropy of the expansion of the Universe by estimating the hemispherical anisotropy of supernova type Ia (SN Ia) Hubble diagrams at low redshifts (z<0.2). We compare the best fit Hubble diagrams in pairs of hemispheres and…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-25 Benedict Bahr-Kalus , Dominik J. Schwarz , Marina Seikel , Alexander Wiegand

We decompose Pantheon+ Type Ia supernovae (SN) in hemispheres on the sky finding angular variations up to $4$ km/s/Mpc in the Hubble constant $H_0$ both in the SH0ES redshift range $0.0233 < z < 0.15$ and in extended redshift ranges. The…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-09 Ruairí McConville , Eoin Ó Colgáin
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