English
Related papers

Related papers: Anisotropy of Cosmic Acceleration

200 papers

We present a method to test the isotropy of the magnitude-redshift relation of Type Ia Supernovae (SNe Ia) and single out the most discrepant direction (in terms of the signal-to-noise ratio) with respect to the all-sky data. Our technique…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-31 Behnam Javanmardi , Cristiano Porciani , Pavel Kroupa , Jan Pflamm-Altenburg

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 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

The peculiar motion of the Earth causes a dipole anisotropy modulation in the distant galaxy distribution due to the aberration effect. However, the amplitude and angular direction of the effect is not necessarily the same as those of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Yousuke Itoh , Kazuhiro Yahata , Masahiro Takada

A cosmological preferred direction was reported from the type Ia supernovae (SNe Ia) data in recent years. We use the Union2.1 data to give a simple classification of such studies for the first time. Because the maximum anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 Xiaofeng Yang , F. Y. Wang , Zhe Chu

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

The cosmographic expansion history of the universe is investigated by using the 557 type Ia supernovae from the Union2 Compilation set along with the current estimates involving the product of the CMB acoustic scale $\ell_{A}$ and the BAO…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 B. Santos , J. C. Carvalho , J. S. Alcaniz

We question the global universe isotropy by probing the alignment of local structures in the cosmic microwave background (CMB) radiation. The original method proposed relies on a steerable wavelet decomposition of the CMB signal on the…

Astrophysics · Physics 2007-05-23 Y. Wiaux , P. Vielva , E. Martinez-Gonzalez , P. Vandergheynst

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

We present a novel approach to disentangle two key contributions to the largest-scale anisotropy of the galaxy distribution: (i) the intrinsic dipole due to clustering and anisotropic geometry, and (ii) the kinematic dipole due to our…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-09 Tobias Nadolny , Ruth Durrer , Martin Kunz , Hamsa Padmanabhan

It is well known that the Milgrom's MOND (modified Newtonian dynamics) explains well the mass discrepancy problem in galaxy rotation curves. The MOND predicts a universal acceleration scale below which the Newtonian dynamics is invalid yet.…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-26 Yong Zhou , Zhi-Chao Zhao , Zhe Chang

The arrival directions of Galactic cosmic rays exhibit anisotropies up to the level of one per-mille over various angular scales. Recent observations of TeV-PeV cosmic rays show that the dipole anisotropy has a strong energy dependence with…

High Energy Astrophysical Phenomena · Physics 2019-05-22 Markus Ahlers

Recently, an anisotropic cosmological model was proposed. An arbitrary 1-form, which picks out a privileged axis in the universe, was added to the Friedmann-Robertson-Walker line element. The distance-redshift relation was modified such…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-14 Zhe Chang , Xin Li , Hai-Nan Lin , Sai 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

The hard X-ray (>2 keV) emission of the local and distant Universe as observed with the HEAO1-A2 experiment is reconsidered in the context of large scale cosmic structure. Using all-sky X-ray samples of AGN and galaxy clusters we remove the…

Astrophysics · Physics 2009-10-31 C. A. Scharf , K. Jahoda , M. Treyer , O. Lahav , E. Boldt , T. Piran

We are in motion against the cosmic backdrop. This motion is evidenced by the systematic temperature shift - or dipole anisotropy - observed in the Cosmic Microwave Background radiation (CMB). Because of the Doppler effect, the temperature…

Astrophysics · Physics 2015-06-24 Chris Blake , Jasper Wall

The anisotropy associated with the initial dipole asymmetry in heavy ion collisions is studied via the two-particle relative azimuthal azimuthal angle (\Delta\phi=\phi^a-\phi^b) correlations, within a multi-phase transport model. For a…

Nuclear Theory · Physics 2013-09-17 Jiangyong Jia , Sooraj K. Radhakrishnan , Soumya Mohapatra

We test the isotropy of the local Universe using low redshift supernova data from various catalogs and the non-parametric method of smoothed residuals. Using a recently developed catalog which combines supernova data from various surveys,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Stephen Appleby , Arman Shafieloo , Andrew Johnson

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

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