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Low multipoles ($l$) in cosmic microwave background (CMB) temperature anisotropies have shown some `peculiarities' when examined since the release of the full sky CMB maps, using a variety of tests. In this paper, we concern ourselves with…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-01 Pavan Kumar Aluri , Sanjeet Kumar Patel

Using the formalism of spin-weighted functions we present an all-sky analysis of polarization in the Cosmic Microwave Background (CMB). Linear polarization is a second-rank symmetric and traceless tensor, which can be decomposed on a sphere…

Astrophysics · Physics 2009-10-28 Matias Zaldarriaga , Uros Seljak

We study the position estimation of a mechanical oscillator undergoing both detuned parametric amplification and continuous quantum measurement. This model, which can be utilised to produce squeezed states, is applied to a general…

Quantum Physics · Physics 2012-10-01 Alex Szorkovszky , Andrew C. Doherty , Glen I. Harris , Warwick P. Bowen

In addition to shear and vorticity a homogeneous background may also exhibit anisotropic curvature. Here a class of spacetimes is shown to exist where the anisotropy is solely of the latter type, and the shear-free condition is supported by…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Tomi S. Koivisto , David F. Mota , Miguel Quartin , Tom G. Zlosnik

We explore the reconstruction of the gravitational lensing field of the cosmic microwave background in real space showing that very little statistical information is lost when estimators of short range on the celestial sphere are used in…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Martin Bucher , Carla Sofia Carvalho , Kavilan Moodley , Mathieu Remazeilles

Future experiments will produce high-resolution temperature maps of the cosmic microwave background (CMB) and are expected to reveal the signature of gravitational lensing by intervening large-scale structures. We construct all-sky…

Astrophysics · Physics 2009-11-07 Christopher M. Hirata , Uros Seljak

Airspace sectorisation provides a partition of a given airspace into sectors, subject to geometric constraints and workload constraints, so that some cost metric is minimised. We survey the algorithmic aspects of methods for automatic…

Other Computer Science · Computer Science 2013-11-05 Pierre Flener , Justin Pearson

A persistent signal of power asymmetry on opposite hemispheres of CMB sky was seen in full-sky temperature measurements made so far. This asymmetry was seen in microwave sky from WMAP as well as PLANCK satellites, and calls for attention…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-03 Pavan K. Aluri , Arman Shafieloo

The presence of matter in the path of relic photons causes distortions in the angular pattern of the cosmic microwave background (CMB) temperature fluctuations, modifying their properties in a slight but measurable way. Recently, the Planck…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-11 G. A. Marques , C. P. Novaes , A. Bernui , I. S. Ferreira

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 Duncan Hanson , Antony Lewis , Anthony Challinor

The paper addresses the stabilization of nonlinear systems with semi-quadratic cost: quadratic with respect to controls and nonlinear for state variables. Paper presents the effective new feedback synthesis procedure. The novel feedback…

Optimization and Control · Mathematics 2008-01-31 S. Nikitin

Despite the fact that the physics of the cosmic microwave background anisotropies is most naturally expressed in Fourier space, pixelised maps are almost always used in the analysis and simulation of microwave data. A complementary approach…

We derive optimal estimators for the two-, three-, and four-point correlators of statistically isotropic scalar fields defined on the sphere, such as the Cosmic Microwave Background temperature fluctuations, allowing for arbitrary (linear)…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Oliver H. E. Philcox

The Quadratic Maximum Likelihood estimator can be used to reconstruct the Cosmic Microwave Background (CMB) power spectra with minimal error bars. Still, it requires an accurate estimate of the datasets noise covariance matrix in order to…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-28 S. Vanneste , S. Henrot-Versillé , T. Louis , M. Tristram

We consider the benefits of measuring cosmic statistical anisotropy from redshift-space correlators of the galaxy number density fluctuation and the peculiar velocity field without adopting the plane-parallel (PP) approximation. Since the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Maresuke Shiraishi , Teppei Okumura , Kazuyuki Akitsu

We compute the reduced cosmic shear up to second order in the gravitational potential without relying on the small angle or thin-lens approximation. This is obtained by solving the Sachs equation which describes the deformation of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-14 Francis Bernardeau , Camille Bonvin , Filippo Vernizzi

The statistical properties of the temperature anisotropies and polarization of the of cosmic microwave background (CMB) radiation offer a powerful probe of the physics of the early universe. In recent works a statistical procedure based…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 M. J. Reboucas , A. Bernui

A spatial point pattern is called anisotropic if its spatial structure depends on direction. Several methods for anisotropy analysis have been introduced in the literature. In this paper, we give an overview of nonparametric methods for…

Methodology · Statistics 2018-03-01 Tuomas Rajala , Claudia Redenbach , Aila Särkkä , Martina Sormani

We consider several factors concerning the design of observing strategies in Cosmic Microwave Background (CMB) anisotropy experiments. First we consider the number of independent points on the sky one should observe given a fixed observing…

Astrophysics · Physics 2007-05-23 R. K. Schaefer , L. Piccirillo

This is a review of the theory of CMB anisotropies, an updated version of a course given at the troisieme cycle de la Suisse Romande. An introduction to gauge invariant cosmological perturbation theory is given and the theory CMB…

Astrophysics · Physics 2014-10-13 Ruth Durrer