English
Related papers

Related papers: Generating Intrinsic Dipole Anisotropy in the Larg…

200 papers

We review the evidence behind recent claims of spatial variation in the fine structure constant deriving from observations of ionic absorption lines in the light from distant quasars. To this end we expand upon previous non-Bayesian…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-12 Ewan Cameron , Tony Pettitt

There is tentative evidence for a mismatch between the rest frames of matter and the cosmic microwave background, the "quasar dipole anomaly". We consider such a dipole in tilted anisotropic models, for a range of scenarios and sources:…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-04 Alicia Martín , Constantinos Skordis , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira , Tariq Yasin

Anisotropies in the distance-redshift relation of cosmological sources are expected due to large-scale inhomogeneities in the local Universe. When the observed sources are tracing a large-scale matter flow in a general spacetime geometry,…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-05 Julian Adamek , Chris Clarkson , Ruth Durrer , Asta Heinesen , Martin Kunz , Hayley J. Macpherson

The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of $H_0$ estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-15 Antonio Enea Romano

Recent studies have indicated that an anisotropic cosmic expansion may exist. In this paper, we use three datasets of type Ia supernovae (SNe Ia) to probe the isotropy of cosmic acceleration. For the Union2.1 dataset, the direction and…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Z. Q. Sun , F. Y. Wang

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

In view of the growing tension between the dipole anisotropy of number counts of cosmologically distant sources and of the cosmic microwave background (CMB), we investigate the number count dipole induced by primordial perturbations with…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-11 Guillem Domènech , Roya Mohayaee , Subodh P. Patil , Subir Sarkar

We measure the anisotropy of dark matter flows on small scales in the near environment of haloes using a large set of simulations. We rely on two different approaches to quantify the anisotropy of the cosmic infall: we measure the flows at…

Astrophysics · Physics 2009-11-10 Dominique Aubert , Christophe Pichon , Stephane Colombi

We describe an algorithm for constructing N-body realizations of equilibrium spherical systems. A general form for the mass density rho(r) is used, making it possible to represent most of the popular density profiles found in the…

Astrophysics · Physics 2009-11-10 Stelios Kazantzidis , John Magorrian , Ben Moore

We carry out fully 3-dimensional simulations of evolution from self-similar, spherically symmetric linear perturbations of a Cold Dark Matter dominated Einstein-de Sitter universe. As a result of the radial orbit instability, the haloes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Mark Vogelsberger , Roya Mohayaee , Simon D. M. White

We have reanalyzed and compared the dipoles of the 1.2 Jy and 0.6 Jy (QDOT) IRAS galaxy samples. We find strong indications from both samples for (a) significant contributions to the gravitational field that shapes the Local Group motion…

Astrophysics · Physics 2009-10-30 S. Basilakos , M. Plionis

Recent observations have identified a significant 4.9$\sigma$ tension between the cosmic dipole inferred from galaxy number counts and that derived from the Cosmic Microwave Background (CMB), suggesting a potential deviation from the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-29 Ge Chen , Chengcheng Han , Linwei Qiu

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

The origin of power asymmetry and other measures of statistical anisotropy on the largest scales of the universe, as manifested in Cosmic Microwave Background (CMB) and large-scale structure data, is a long-standing open question in…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-12 Pablo Fosalba , Enrique Gaztanaga

We investigate the sensitivity of the Laser Interferometer Space Antenna (LISA) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We first discuss the main astrophysical and cosmological sources of SGWB which are…

A combined sample of 79 high and low redshift supernovae Ia (SNe) is used to set constraints on the degree of anisotropy in the Universe out to $z\simeq1$. First we derive the global most probable values of matter density $\Omega_M $, the…

Astrophysics · Physics 2015-06-24 Tsafrir S. Kolatt , Ofer Lahav

We have found that the phase-space of a dark matter particles assembling a galactic halo in cosmological N-body simulations has well defined fine grained structure. Recently accreted particles form distinctive velocity streams with high…

Astrophysics of Galaxies · Physics 2015-06-11 K. Dolag , A. D. Dolgov , I. I. Tkachev

We calculate the large-scale cosmic-ray (CR) anisotropies predicted for a range of Goldreich-Sridhar (GS) and isotropic models of interstellar turbulence, and compare them with IceTop data. In general, the predicted CR anisotropy is not a…

High Energy Astrophysical Phenomena · Physics 2017-02-07 Gwenael Giacinti , John G. Kirk

We show that perturbations generated during the anisotropic pre-inflationary stage of cosmic evolution may affect cosmological observations today for a certain range of parameters. Due to the anisotropic nature of the universe during such…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-15 Pavan K. Aluri , Pankaj Jain

We estimate the acceleration on the Local Group (LG) from the Two Micron All Sky Redshift Survey (2MRS). The sample used includes about 23,200 galaxies with extinction corrected magnitudes brighter than K_s=11.25 and it allows us to…

‹ Prev 1 3 4 5 6 7 10 Next ›