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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

Gravitational lensing of the CMB is a valuable cosmological signal that correlates to tracers of large-scale structure and acts as a important source of confusion for primordial $B$-mode polarization. State-of-the-art lensing reconstruction…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-05 Julien Carron , Antony Lewis

Efforts to detect a primordial $B$-mode of CMB polarization generated by inflationary gravitational waves ought to mitigate the large variance associated with the $B$-modes produced by gravitational lensing, a process known as delensing. A…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Antón Baleato Lizancos , Anthony Challinor , Julien Carron

Ground-based solar image restoration is a computationally expensive procedure that involves nonlinear optimization techniques. The presence of atmospheric turbulence produces perturbations in individual images that make it necessary to…

Instrumentation and Methods for Astrophysics · Physics 2023-07-26 A. Asensio Ramos , S. Esteban Pozuelo , C. Kuckein

Cross-survey generalization is a critical challenge in stellar spectral analysis, particularly in cases such as transferring from low- to moderate-resolution surveys. We investigate this problem using pre-trained models, focusing on simple…

Solar and Stellar Astrophysics · Physics 2026-02-17 Xiaosheng Zhao , Yuan-Sen Ting , Rosemary F. G. Wyse , Alexander S. Szalay , Yang Huang , László Dobos , Tamás Budavári , Viska Wei

We present a minimally parametric, model independent reconstruction of the shape of the primordial power spectrum. Our smoothing spline technique is well-suited to search for smooth features such as deviations from scale invariance, and…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Andrea Ravenni , Licia Verde , Antonio J. Cuesta

Component separation methods mitigate the cross-contamination between different extragalactic and galactic contributions to cosmic microwave background (CMB) data. This is often done by linearly combining CMB maps from different frequency…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-26 Jack Y. L. Kwok , William R. Coulton , Niall MacCrann , Fiona McCarthy , Boris Bolliet , Blake D. Sherwin

Image restoration is typically addressed through non-convex inverse problems, which are often solved using first-order block-wise splitting methods. In this paper, we consider a general type of non-convex optimisation model that captures…

In this work, we consider the application of model-based deep learning in nonlinear principal component analysis (PCA). Inspired by the deep unfolding methodology, we propose a task-based deep learning approach, referred to as Deep-RLS,…

Signal Processing · Electrical Eng. & Systems 2020-11-19 Zahra Esmaeilbeig , Shahin Khobahi , Mojtaba Soltanalian

The primordial power spectrum describes the initial perturbations in the Universe which eventually grew into the large-scale structure we observe today, and thereby provides an indirect probe of inflation or other structure-formation…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 P. Paykari , F. Lanusse , J. -L. Starck , F. Sureau , J. Bobin

We explore a class of primordial power spectra that can fit the observed anisotropies in the cosmic microwave background well and that predicts a value for the Hubble parameter consistent with the local measurement of $H_0 = 74$ km/s/Mpc.…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Ryan E. Keeley , Arman Shafieloo , Dhiraj Kumar Hazra , Tarun Souradeep

The delensing procedure is an effective tool for removing lensing-induced $B$-mode polarization in the Cosmic Microwave Background to allow for deep searches of primordial $B$-modes. However, the delensing algorithm existing in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-01 Wei-Hsiang Teng , Chao-Lin Kuo , Jiun-Huei Proty Wu

The primordial power spectrum is an indirect probe of inflation or other structure-formation mechanisms. We introduce a new method, named \textbf{PRISM}, to estimate this spectrum from the empirical cosmic microwave background (CMB) power…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 P. Paykari , F. Lanusse , J. -L. Starck , F. Sureau , J. Bobin

Pursuing the original idea proposed in our previous paper (Paper I), we improve the method to determine the shape of the initial curvature perturbation spectrum $P(k)$ from the CMB data. The thickness of the last scattering surface (LSS)…

Astrophysics · Physics 2009-10-09 Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

The subject of this paper is beam deconvolution in small angular scale CMB experiments. The beam effect is reversed using the Jacobi iterative method, which was designed to solved systems of algebraic linear equations. The beam is a non…

Astrophysics · Physics 2009-11-07 Carlo Burigana , Diego Saez

The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\rm NL}^{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 J. Colin Hill

Deconvolution algorithms have been used successfully for optimization/restoration/deblurring of astronomical images in a variety of wavelengths, especially in the optical band (e.g., for HST). We present here an iterative Richardson-Lucy…

Astrophysics · Physics 2007-11-15 G. Maurin , A. Djannati-Atai , P. Espigat

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

This paper is concerned with experiments which measure CMB anisotropies on small angular scales. A certain coverage, a beam structure and a level of uncorrelated noise define each experiment. We focus our atention on the reversion of the…

Astrophysics · Physics 2009-10-31 J. V. Arnau , D. Saez

Image deblurring, a.k.a. image deconvolution, recovers a clear image from pixel superposition caused by blur degradation. Few deep convolutional neural networks (CNN) succeed in addressing this task. In this paper, we first demonstrate that…

Computer Vision and Pattern Recognition · Computer Science 2018-11-06 Li Si-Yao , Dongwei Ren , Furong Zhao , Zijian Hu , Junfeng Li , Qian Yin