English
Related papers

Related papers: The Cosmic Dipole in the Quaia Sample of Quasars: …

200 papers

The foundation of modern cosmology relies on the so-called cosmological principle which states an homogeneous and isotropic distribution of matter in the universe on large scales. However, recent observations, such as the temperature…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-18 Wen Zhao , Larissa Santos

The two fundamental assumptions in cosmology are that the Universe is statistically homogeneous and isotropic when averaged on large scales. Given the big implication of these assumptions, there has been a lot of statistical tests carried…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Yabebal Fantaye

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

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

In recent years, large radio surveys of Active Galactic Nuclei (AGNs), comprising millions of sources, have become available where one could investigate dipole asymmetries, assumedly arising due to a peculiar motion of the Solar system.…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-21 Ashok K. Singal

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

Cosmic microwave background measurements show an agreement with the concordance cosmology model except for a few notable anomalies: Power Suppression, the lack of large scale power in the temperature data compared to what is expected in the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-20 Shabbir Shaikh , Suvodip Mukherjee , Santanu Das , Benjamin D. Wandelt , Tarun Souradeep

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

One of the main pillars of the {\Lambda}CDM model is the Cosmological Principle, which states that our Universe is statistically isotropic and homogeneous on large scales. Here we test this hypothesis using the Astrophysical Gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-06 Lorenzo Valbusa Dall'Armi , Angelo Ricciardone , Daniele Bertacca

Recent analyses of the cosmic microwave background (CMB) maps from the WMAP satellite have uncovered evidence for a hemispherical power anomaly, i.e. a dipole modulation of the CMB power spectrum at large angular scales with an amplitude of…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-28 Christopher M. Hirata

We apply Simulation-Based Inference ('SBI') to the cosmic dipole problem for the first time, measuring the distribution of quasar counts over the sky in the CatWISE2020 ('CatWISE') sample. We show that the quadrupole anisotropy in CatWISE…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Oliver T. Oayda , Geraint F. Lewis

There is increasing evidence suggesting a discrepancy between the cosmic dipole observed in the number count of distant galaxies and the one derived from the cosmic microwave background (CMB). In this study, we investigate the possibility…

High Energy Physics - Phenomenology · Physics 2023-08-02 Chengcheng Han

We present a new approach to constructing and fitting dipoles and higher-order multipoles in synthetic galaxy samples over the sky. Within our Bayesian paradigm, we illustrate that this technique is robust to masked skies, allowing us to…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-18 Oliver T. Oayda , Vasudev Mittal , Geraint F. Lewis

We study the dipole signal in the spectral index (x) of the differential number counts using quasars in the CatWISE2020 catalog of infrared sources. The index is extracted by using the log-likelihood method. We obtain the value $x=1.579 \pm…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-29 Mohit Panwar , Pankaj Jain

We have studied the cosmic microwave background (CMB) map looking for features beyond cosmological isotropy. We began by tiling the CMB variance map (which are produced by different smoothing scales) with stripes of different sizes along…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-12 MohammadHossein Jamshidi , Abdolali Banihashemi , Nima Khosravi

We present posterior sample-based cosmic microwave background (CMB) constraints from Planck LFI and WMAP observations derived through global end-to-end Bayesian processing. We use these samples to study correlations between CMB, foreground,…

The dipole anisotropy seen in the {cosmic microwave background radiation} is interpreted as due to our peculiar motion. The Cosmological Principle implies that this cosmic dipole signal should also be present, with the same direction, in…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Carlos A. P. Bengaly , Thilo M. Siewert , Dominik J. Schwarz , Roy Maartens

Modern cosmology rests on the working assumption that the Universe is isotropic and homogeneous at large scales. Here, we document a number of anomalous observations pointing to an anisotropic Universe in a direction consistent with the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-22 Eoin Ó Colgáin

The cosmic microwave background (CMB) is a relic radiation of the Big Bang and as such it contains a wealth of cosmological information. Statistical analyses of the CMB, in conjunction with other cosmological observables, represent some of…

If gamma-ray bursts originate at cosmological distances then their angular distribution should exhibit a dipole in the direction of the solar motion relative to the cosmic microwave background. This is due to the combined effects of…

Astrophysics · Physics 2009-10-22 Eyal Maoz