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相关论文: Real-space computation of $E$/$B$-mode maps I: For…

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In a microwave background polarization map that covers only part of the sky, it is impossible to separate the E and B components perfectly. This difficulty in general makes it more difficult to detect the B component in a data set. Any…

天体物理学 · 物理学 2015-06-24 Emory F. Bunn

Correlations of polarization components in the coordinate frame are a natural basis for searches of parity-violating modes in the Cosmic Microwave Background (CMB). This fact can be exploited to build estimators of parity-violating modes…

宇宙学与河外天体物理 · 物理学 2017-02-22 Carlo R. Contaldi

Kernel methods in machine learning use a kernel function that takes two data points as input and returns their inner product after mapping them to a Hilbert space, implicitly and without actually computing the mapping. For many kernel…

机器学习 · 计算机科学 2024-10-17 Kamaledin Ghiasi-Shirazi , Mohammadreza Qaraei

Background Imaging of Cosmic Extragalactic Polarization (BICEP) is a bolometric polarimeter designed to measure the inflationary B-mode polarization of the cosmic microwave background (CMB) at degree angular scales. During three seasons of…

To study the early Universe, it is essential to estimate cosmological parameters with high accuracy, which depends on the optimal reconstruction of Cosmic Microwave Background (CMB) maps and the measurement of their power spectrum. In this…

宇宙学与河外天体物理 · 物理学 2025-06-10 Belén Costanza , Claudia G. Scóccola , Matías Zaldarriaga

In this paper we estimate diffuse foreground minimized Cosmic Microwave Background (CMB) Stokes Q and U polarization maps based upon the fundamental concept of Gaussian nature of CMB and strong non-Gaussian nature of astrophysical polarized…

宇宙学与河外天体物理 · 物理学 2017-07-10 Ujjal Purkayastha , Rajib Saha

We study how iterated and composed completely positive maps act on operator-valued kernels. Each kernel is realized inside a single Hilbert space where composition corresponds to applying bounded creation operators to feature vectors. This…

泛函分析 · 数学 2025-11-18 James Tian

The observation of the polarised emission from the Cosmic Microwave Background (CMB) from future ground-based and satellite-borne experiments holds the promise of indirectly detecting the elusive signal from primordial tensor fluctuations…

宇宙学与河外天体物理 · 物理学 2023-03-22 Susanna Azzoni , David Alonso , Maximilian H. Abitbol , Josquin Errard , Nicoletta Krachmalnicoff

This work provides theoretical foundations for kernel methods in the hyperspherical context. Specifically, we characterise the native spaces (reproducing kernel Hilbert spaces) and the Sobolev spaces associated with kernels defined over…

机器学习 · 统计学 2022-11-18 Simon Hubbert , Emilio Porcu , Chris. J. Oates , Mark Girolami

We consider the effectiveness of foreground cleaning in the recovery of Cosmic Microwave Background (CMB) polarization sourced by gravitational waves for tensor-to-scalar ratios in the range $0<r<0.1$. Using the planned survey area,…

We present the application of the Fast Independent Component Analysis ({\ica}) technique for blind component separation to polarized astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarized signal, consisting of…

天体物理学 · 物理学 2009-06-16 C. Baccigalupi , F. Perrotta , G. De Zotti , G. F. Smoot , C. Burigana , D. Maino , L. Bedini , E. Salerno

The cosmic microwave background (CMB) experiments have reached an era of unprecedented precision and complexity. Aiming to detect the primordial B-mode polarization signal, these experiments will soon be equipped with $10^{4}$ to $10^{5}$…

宇宙学与河外天体物理 · 物理学 2025-11-05 Avinash Anand , Giuseppe Puglisi

We extend the pure pseudo-power-spectrum formalism proposed recently in the context of the Cosmic Microwave Background polarized power spectra estimation by Smith (2006) to incorporate cross-spectra computed for multiple maps of the same…

宇宙学与河外天体物理 · 物理学 2009-07-09 J. Grain , M. Tristram , R. Stompor

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

天体物理学 · 物理学 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

The polarization of the cosmic microwave background (CMB) can be used to search for parity-violating processes like that predicted by a Chern-Simons coupling to a light pseudoscalar field. Such an interaction rotates $E$ modes into $B$…

Cosmic birefringence, arising from a potential parity-violating interaction between cosmic microwave background (CMB) photons and evolving pseudo-scalar fields such as axion-like particles, can rotate the CMB polarization plane and induce…

宇宙学与河外天体物理 · 物理学 2025-10-27 Mathieu Remazeilles

We present an augmented version of our dual messenger algorithm for spin field reconstruction on the sphere, while accounting for highly non-trivial and realistic noise models such as modulated correlated noise. We also describe an…

宇宙学与河外天体物理 · 物理学 2019-10-01 Doogesh Kodi Ramanah , Guilhem Lavaux , Benjamin D. Wandelt

This paper considers the approximation of spatial convolution with a given radial integral kernel. Previous studies have demonstrated that approximating spatial convolution using a system of partial differential equations (PDEs) can…

偏微分方程分析 · 数学 2025-04-15 Hiroshi Ishii , Yoshitaro Tanaka

Detailed measurements of the CMB lensing signal are an important scientific goal of ongoing ground-based CMB polarization experiments, which are mapping the CMB at high resolution over small patches of the sky. In this work we simulate CMB…

宇宙学与河外天体物理 · 物理学 2014-07-30 Ruth Pearson , Blake Sherwin , Antony Lewis

Ever since Cosmic Microwave Background (CMB) signal is being measured by various satellites based observations with increasing experimental accuracies there has been a parallel increase in the demand for a CMB reconstruction technique which…

宇宙学与河外天体物理 · 物理学 2020-04-21 Ujjal Purkayastha , Vipin Sudevan , Rajib Saha