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Large-scale structure surveys can be used to measure the dipole in the cosmic microwave background (CMB), in the luminosity distances inferred from type-Ia supernova observations, and in the spatial distribution of galaxies and quasars. The…

宇宙学与河外天体物理 · 物理学 2025-12-08 Jaiyul Yoo , Matteo Magi , Dragan Huterer

By decomposing the CMB temperature fluctuations \emph{squared} into spherical harmonics, we can define the \emph{CMB power multipoles} as the fundamental observables to quantify any generic modulations in the CMB. This allows for simple…

宇宙学与河外天体物理 · 物理学 2014-01-09 Lingfei Wang

The power spectrum of fluctuations in the cosmic microwave background (CMB) depends on most of the key cosmological parameters. Accurate future measurements of this power spectrum might therefore allow us to determine h, Omega, Omega_b,…

天体物理学 · 物理学 2007-05-23 Max Tegmark

Several statistical anomalies in the CMB temperature anisotropies seem to defy the assumption of a homogeneous and isotropic universe. In particular, a dipole modulation has been detected both in WMAP and Planck data. We adapt the…

宇宙学与河外天体物理 · 物理学 2014-07-29 R. Fernández-Cobos , P. Vielva , D. Pietrobon , A. Balbi , E. Martínez-González , R. B. Barreiro

The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. This assumption of {\em statistical isotropy} (SI) of the CMB anisotropy should…

天体物理学 · 物理学 2009-11-10 Amir Hajian , Tarun Souradeep

The largest anisotropy in the cosmic microwave background (CMB) is the $\approx 3$ mK dipole assumed to be due to our velocity with respect to the CMB. Over the past ten years the precision of our knowledge of the dipole has increased by a…

天体物理学 · 物理学 2007-05-23 Charles H. Lineweaver

This paper discusses the Cosmic Background (CB) dipoles observations in the framework of the Planck mission. Dipoles observations can be used in three ways: (i) It gives a measurement of the peculiar velocity of our Galaxy which is an…

天体物理学 · 物理学 2009-11-07 M. Piat , G. Lagache , J. P. Bernard , M. Giard , J. L. Puget

Our motion relative to the cosmic-microwave-background (CMB) rest frame deflects light rays giving rise to shifts as large as L -> L(1+beta), where beta=0.00123 is our velocity (in units of the speed of light) on measurements CMB…

宇宙学与河外天体物理 · 物理学 2014-01-22 Donghui Jeong , Jens Chluba , Liang Dai , Marc Kamionkowski , Xin Wang

According to the Cosmological Principle, the matter distribution on very large scales should have a kinematic dipole that is aligned with that of the CMB. We determine the dipole anisotropy in the number counts of two all-sky surveys of…

宇宙学与河外天体物理 · 物理学 2018-04-11 C. A. P. Bengaly , R. Maartens , M. G. Santos

The largest fluctuation in the CMB sky is the CMB dipole, which is believed to be caused by the motion of our observation frame with respect to the CMB rest frame. This motion accounts for the known motion of the Solar System barycentre…

宇宙学与河外天体物理 · 物理学 2021-11-19 Sayan Saha , Shabbir Shaikh , Suvodip Mukherjee , Tarun Souradeep , Benjamin D. Wandelt

We investigate the impact of peculiar velocity effects due to the motion of the solar system relative to the microwave background (CMB) on high resolution CMB experiments. It is well known that on the largest angular scales the combined…

天体物理学 · 物理学 2009-11-07 Anthony Challinor , Floor van Leeuwen

Primordial statistical anisotropy is a key indicator to investigate early Universe models and has been probed by the cosmic microwave background (CMB) anisotropies. In this paper, we examine tensor-mode CMB fluctuations generated from…

宇宙学与河外天体物理 · 物理学 2014-07-29 Maresuke Shiraishi , David F. Mota , Angelo Ricciardone , Frederico Arroja

The origin of small deviations from statistical isotropy in the Cosmic Microwave Background (CMB) - the so-called CMB anomalies - remains an open question in modern cosmology. In this work, we test statistical isotropy in Planck Data…

宇宙学与河外天体物理 · 物理学 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

天体物理学 · 物理学 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

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.…

宇宙学与河外天体物理 · 物理学 2023-12-21 Ashok K. Singal

A fundamental assumption in cosmology is that of statistical isotropy - that the universe, on average, looks the same in every direction in the sky. Statistical isotropy has recently been tested stringently using Cosmic Microwave Background…

宇宙学与河外天体物理 · 物理学 2011-09-14 Caroline Zunckel , Dragan Huterer , Glenn D. Starkman

Low amplitude (linear regime) cosmic density fluctuations lead to spatial variations in the locally measurable value of $H_0$ (denoted as $H_L$), $\delta_H \equiv (H_L-H_0)/H_0$, which are of order 3-6% (95% confidence interval) in a sphere…

天体物理学 · 物理学 2009-10-30 Yun Wang , David N. Spergel , Edwin L. Turner

Most cosmological parameters are expected to change significantly only on cosmological time scales, but given the large amount of information contained within the Cosmic Microwave Background (CMB) sky, we can expect that changes in the CMB…

天体物理学 · 物理学 2008-12-18 Adam Moss , James P. Zibin , Douglas Scott

We present a general framework for accurate spectral modeling of the low multipoles of the cosmic microwave background (CMB) as observed in a boosted frame. In particular, we demonstrate how spectral measurements of the low multipoles can…

宇宙学与河外天体物理 · 物理学 2017-12-06 Siavash Yasini , Elena Pierpaoli

We introduce a pixel space method to detect dipole modulation or hemispherical power asymmetry in the cosmic microwave background (CMB) polarization. The method relies on the use of squared total polarized flux whose ensemble average picks…

宇宙学与河外天体物理 · 物理学 2020-07-15 Shamik Ghosh , Pankaj Jain