English
Related papers

Related papers: Probing the isotropy of cosmic acceleration using …

200 papers

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

Type Ia supernovae (SNe Ia) were instrumental in establishing the acceleration of the universe's expansion. By virtue of their combination of distance reach, precision, and prevalence, they continue to provide key cosmological constraints,…

The cosmological principle asserts that the Universe looks spatially homogeneous and isotropic on sufficiently large scales. Given the fundamental implications of the cosmological principle, it is important to empirically test its validity…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Suhail Dhawan , Antonin Borderies , Hayley J. Macpherson , Asta Heinesen

We obtain the dipolar anisotropies in the arrival directions of ultra-high energy cosmic ray nuclei diffusing from nearby extragalactic sources. We consider mixed-composition scenarios in which different cosmic ray nuclei are accelerated up…

High Energy Astrophysical Phenomena · Physics 2015-09-30 Diego Harari , Silvia Mollerach , Esteban Roulet

Recent released Planck data and other astronomical observations show that the universe may be anisotropic on large scales. This hints a cosmological privileged axis in our anisotropic expanding universe. This paper proceeds a modified…

General Relativity and Quantum Cosmology · Physics 2017-11-29 Amin Salehi , Mohammad Reza Setare

In this Letter, by reconstructing the $Om$ diagnostic and the deceleration parameter $q$ from the latest Union2 Type Ia supernova sample with and without the systematic error along with the baryon acoustic oscillation (BAO) and the cosmic…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Zhengxiang Li , Puxun Wu , Hongwei Yu

Under nonuniform convection, the distribution of diffusive particles can exhibit dipole and quadrupole anisotropy induced by the fluid inertial and shear force, respectively. These convection-related anisotropies, unlike the Compton-Getting…

High Energy Astrophysical Phenomena · Physics 2022-10-26 Yiran Zhang , Siming Liu , Dejin Wu

In this study we investigate potential large-angle anisotropies in the angular distribution of the cosmological parameters $H_0$ (the Hubble constant) and $\Omega_m$ (the matter density) in the flat-$\Lambda$CDM framework, using the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-08 Rahima Mokeddem , Maria Lopes , Felipe Avila , Armando Bernui , Wiliam S. Hipólito-Ricaldi

We examine the Type 1a supernova data in order to determine if it shows any signal of large scale anisotropy. The anisotropy is modelled by an extended G\"{o}del metric, which incorporates expansion along with rotation. The model is…

Astrophysics · Physics 2008-11-26 Pankaj Jain , Moninder S. Modgil , John P. Ralston

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

In this manuscript, we investigate the patterns satisfied by the cosmological anisotropy under the hypothesis of the observers being co-moving with a perfect fluid whose induced space sections are homogeneous with vanishing scalar…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Leandro G. Gomes

A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

A conventional explanation of the dipole anisotropy of the cosmic microwave background (CMB) radiation is in terms of the Doppler effect: our galaxy is moving with respect to CMB frame with $ \sim 600 ~ km ~ s^{-1} $. However, as the deep…

Astrophysics · Physics 2007-05-23 M. Jaroszynski , B. Paczynski

Recent measurements of type Ia supernovae as well as other concordant observations suggest that the expansion of our universe is accelerating. A dark energy component has usually been invoked as the most feasible mechanism for the…

Astrophysics · Physics 2014-10-13 Zong-Hong Zhu , Masa-Katsu Fujimoto , Xiang-Tao He

This research explores the correlation between the absolute magnitude and the redshift of Type Ia supernovae (SNe Ia) with a model-independent approach. The Pantheon sample of SNe Ia and strong gravitational lensing systems (SGLS) are used.…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-19 Jian Hu , Jian-Ping Hu , Zhongmu Li , Wenchang Zhao , Jing Chen

A spherical cosmological model with a local void on scales of $\sim 200$ Mpc and with an inhomogeneous Hubble constant was proposed in recent two papers. This model explains consistently the observed properties of the cosmic bulk flow, the…

Astrophysics · Physics 2009-10-31 Kenji Tomita

We predict that neutrino sources following the matter distribution of the universe result in an anisotropy in the neutrino sky imprinted by the local large-scale structure. We calculate the level of this anisotropy and explore how it…

High Energy Astrophysical Phenomena · Physics 2025-11-13 Marco Stein Muzio , Noémie Globus

We test the present expansion of the universe using supernova type Ia data without making any assumptions about the matter and energy content of the universe or about the parameterization of the deceleration parameter. We assume the…

Astrophysics · Physics 2009-06-23 Marina Seikel , Dominik J. Schwarz

We test claims of large-scale anisotropy in the local expansion rate using cluster scaling relations as distance indicators. Using a Bayesian forward model, we jointly fit the X-ray luminosity--temperature (LT) and thermal…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Tariq Yasin , Richard Stiskalek , Harry Desmond , Sebastian von Hausegger , Pedro G. Ferreira

Context. Our Local Group of galaxies appears to be moving relative to the cosmic microwave background with the source of the peculiar motion still uncertain. While in the past this has been studied mostly using galaxies as distance…

‹ Prev 1 4 5 6 7 8 10 Next ›