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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

The quest for primordial $B$-mode polarization signatures in the Cosmic Microwave Background (CMB) is a major goal of contemporary cosmology. Detecting these signatures would confirm primordial gravitational waves and allow precise…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Yusuke Takase

The third flight of the Medium Scale Anisotropy Measurement (MSAM1), in June 1995, observed a new strip of sky, doubling the sky coverage of the original MSAM1 dataset. MSAM1 observes with a 0.5 deg beam size in four bands from 5-20 icm.…

We develop a model for correlations of cosmic microwave background anisotropy on the largest angular scales, based on standard causal geometrical relationships in slow-roll inflation. Unlike standard models based on quantized field modes,…

General Relativity and Quantum Cosmology · Physics 2023-08-02 Craig Hogan , Stephan S. Meyer , Nathaniel Selub , Frederick Wehlen

Mechanisms have been proposed that might rotate the linear polarization of the cosmic microwave background (CMB) as it propagates from the surface of last scatter. In the simplest scenario, the rotation will be uniform across the sky, but…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Vera Gluscevic , Marc Kamionkowski , Asantha Cooray

The measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy has proved crucial to the emergence of cosmology as a precision science in recent years. In this remarkable data rich period, the limitations…

Astrophysics · Physics 2007-05-23 Sanjit Mitra , Anand S. Sengupta , Tarun Souradeep

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

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

Astrophysics · Physics 2007-05-23 M. V. Sazhin , G. Sironi , O. S. Khovanskaya

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-24 Giacomo Galloni , Mario Ballardini , Nicola Bartolo , Alessandro Gruppuso , Luca Pagano , Angelo Ricciardone

Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial vector fields in inflationary theories…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 N. Bartolo , E. Dimastrogiovanni , M. Liguori , S. Matarrese , A. Riotto

In the era of high precision CMB measurements, systematic effects are beginning to limit the ability to extract subtler cosmological information. The non-circularity of the experimental beam has become progressively important as CMB…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Sanjit Mitra , Anand Sengupta , Subharthi Ray , Rajib Saha

We investigate a possibility of constraining statistical anisotropies of the primordial tensor perturbations by using future observations for the Cosmic Microwave Background (CMB) B-mode polarization. By parameterizing a…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Takashi Hiramatsu , Shuichiro Yokoyama , Tomohiro Fujita , Ippei Obata

In this paper we use the current and future cosmic microwave background (CMB) experiments to test the Charge-Parity-Time Reversal (CPT) symmetry. We consider a CPT-violating interaction in the photon sector $\mathcal{L}_{\rm cs}\sim p_\mu…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Si-Yu Li , Jun-Qing Xia , Mingzhe Li , Hong Li , Xinmin Zhang

The anisotropies of the cosmic microwave background (CMB) are computed for the half-turn space E_2 which represents a compact flat model of the Universe, i.e. one with finite volume. This model is inhomogeneous in the sense that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Aurich , S. Lustig

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…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 C. A. P. Bengaly , R. Maartens , M. G. Santos

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

Astrophysics · Physics 2009-11-07 M. V. Sazhin , G. Sironi , O. S. Khovanskaya

Cosmological Birefringence (CB), a rotation of the polarization plane of radiation coming to us from distant astrophysical sources, may reveal parity violation in either the electromagnetic or gravitational sectors of the fundamental…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Amit P. S. Yadav , Meir Shimon , Brian G. Keating

Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-22 Maresuke Shiraishi , Angelo Ricciardone , Shohei Saga

The first observations of the cosmic microwave background (CMB) from NASA's \emph{Wilkinson Microwave Anisotropy Probe} (WMAP) led to finding `alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Sanjeet Kumar Patel , Pavan Kumar Aluri , John P. Ralston