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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

We theoretically analyze the dipole anisotropy observed in the quasar distribution from the CatWISE2020 catalog. The catalog data shows a peak around $z\approx 1$, suggesting the presence of a large-scale dipole component. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Gopal Kashyap , Naveen K. Singh , Pankaj Jain

We provide a new derivation of the anisotropies of the cosmic microwave background (CMB), and find an exact expression that can be readily expanded perturbatively. Close attention is paid to gauge issues, with the motivation to examine the…

Astrophysics · Physics 2009-01-08 J. P. Zibin , Douglas Scott

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

The observed dipole asymmetry in Cosmic Microwave Background radiation may have originated from the modulations of super-horizon long wavelength modes. In this work we unveil different aspects of asymmetries generated from the long…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Ali Akbar Abolhasani , Shant Baghram , Hassan Firouzjahi , Mohammad Hossein Namjoo

The scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces polarization signals according to the quadrupole anisotropy in the photon distribution at the cluster location. This `remote quadrupole' derived from…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 Kiyotomo Ichiki , Kento Sumiya , Guo-Chin Liu

Our motion through the Universe generates a dipole in the temperature anisotropies of the Cosmic Microwave Background (CMB) and also in the angular distribution of sources. If the cosmological principle is valid, these two dipoles are…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-09 Charles Dalang , Camille Bonvin

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

The largest temperature anisotropy in the cosmic microwave background (CMB) is the dipole. The simplest interpretation of the dipole is that it is due to our motion with respect to the rest frame of the CMB. As well as creating the $\ell$=1…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-25 Raelyn M. Sullivan , Douglas Scott

We test the usual hypothesis that the Cosmic Microwave Background (CMB) dipole, its largest anisotropy, is due to our peculiar velocity with respect to the Hubble flow by measuring independently the Doppler and aberration effects on the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-06 Pedro da Silveira Ferreira , Miguel Quartin

Superhorizon perturbations induce large-scale temperature anisotropies in the cosmic microwave background (CMB) via the Grishchuk-Zel'dovich effect. We analyze the CMB temperature anisotropies generated by a single-mode adiabatic…

Astrophysics · Physics 2008-11-26 Adrienne L. Erickcek , Sean M. Carroll , Marc Kamionkowski

Many observations in recent times have shown evidence against the standard assumption of isotropy in the Big Bang model. Introducing a superhorizon scalar metric perturbation has been able to explain some of these anomalies. In this work,…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-21 Kaustav K. Das , Kishan Sankharva , Pankaj Jain

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

Scattering of cosmic microwave background (CMB) radiation in galaxy clusters induces polarization signals determined by the quadrupole anisotropy in the photon distribution at the location of clusters. This "remote quadrupole" derived from…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-13 Guo-Chin Liu , Kiyotomo Ichiki , Hiroyuki Tashiro , Naoshi Sugiyama

The velocity of the Sun with respect to the cosmic microwave background (CMB) can be extracted from the CMB dipole, provided its intrinsic dipole is assumed to be small in comparison. This interpretation is consistent, within fairly large…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-24 Charles Dalang , Ruth Durrer , Fabien Lacasa

We propose a new source for the cosmological density perturbation which is passive fluctuations of the inflaton driven dynamically by a colored quantum noise as a result of its coupling to other massive quantum fields. The created…

Astrophysics · Physics 2010-10-27 Chun-Hsien Wu , Kin-Wang Ng , Wolung Lee , Da-Shin Lee , Yeo-Yie Charng

Measurements of the number count dipole with large surveys have shown amplitudes in tension with kinematic predictions based on the observed Doppler dipole of the cosmic microwave background (CMB). These observations seem to be in direct…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-14 J. D. Wagenveld , S. von Hausegger , H-R. Klöckner , D. J. Schwarz

We study cosmological tensor perturbations induced by second-order scalar perturbations in the presence of anisotropic non-Gaussianity. This class of induced tensor modes arises on superhorizon scales through the intrinsic quadrupole…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-13 Atsuhisa Ota

We derive a general expression for the probability of observing deviations from statistical isotropy in the cosmic microwave background (CMB) if the primordial fluctuations are non-Gaussian and extend to superhorizon scales. The primary…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Saroj Adhikari , Sarah Shandera , Adrienne L. Erickcek

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer
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