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Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Md Ishaque Khan , Rajib Saha

For time series data observed at non-random and possibly non-equidistant time points, we estimate the trend function nonparametrically. Under the assumption of a bounded total variation of the function and low-order moment conditions on the…

Statistics Theory · Mathematics 2025-02-13 Michael H. Neumann , Anne Leucht

In this work, we propose a time-varying wave-shape extraction algorithm based on a modified version of the adaptive non-harmonic model for non-stationary signals. The model codifies the time-varying wave-shape information in the relative…

Signal Processing · Electrical Eng. & Systems 2023-09-28 Joaquin Ruiz , Gastón Schlotthauer , Leandro Vignolo , Marcelo A. Colominas

The COBE time ordered data (TOD) was reanalysed for anisotropies in the cosmic microwave background with a novel technique that is much simpler and more robust than used in the official analysis of the COBE TOD. The technique extends the…

Astrophysics · Physics 2007-07-18 Keith S Cover

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-01 Doogesh Kodi Ramanah , Guilhem Lavaux , Benjamin D. Wandelt

In this paper we introduce a significant improvement to the popular tree-based Stochastic Gradient Boosting algorithm using a wavelet decomposition of the trees. This approach is based on harmonic analysis and approximation theoretical…

Machine Learning · Computer Science 2019-05-06 Shai Dekel , Oren Elisha , Ohad Morgan

We suggest a two-dimensional wavelet devised to deduce the large-scale structure of a physical field (e.g., the Galactic magnetic field) from its integrals along straight paths from irregularly spaced data points to a fixed interior point…

Astrophysics · Physics 2009-11-07 R. Stepanov , P. Frick , A. Shukurov , D. Sokoloff

Accurate classification of sleep stages is crucial for the diagnosis and management of sleep disorders. Conventional approaches for sleep scoring rely on manual annotation or features extracted from EEG signals in the time or frequency…

Machine Learning · Computer Science 2025-10-10 Mehdi Zekriyapanah Gashti , Ghasem Farjamnia

Madam is a CMB map-making code, designed to make temperature and polarization maps of time-ordered data of total power experiments like Planck. The algorithm is based on the destriping technique, but it also makes use of known noise…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 E. Keihanen , R. Keskitalo , H. Kurki-Suonio , T. Poutanen , A. -S. Sirvio

We consider dissipative systems resulting from the Gaussian and $alpha$-stable noise perturbations of measure-preserving maps on the $d$ dimensional torus. We study the dissipation time scale and its physical implications as the noise level…

Dynamical Systems · Mathematics 2007-05-23 Albert Fannjiang , Lech Wolowski

We present a self-consistent framework to perform the wavelet analysis of two-dimensional statistical distributions. The analysis targets the 2D probability density function (p.d.f.) of an input sample, in which each object is characterized…

Instrumentation and Methods for Astrophysics · Physics 2019-03-26 R. V. Baluev , E. I. Rodionov , V. Sh. Shaidulin

Observations of the Cosmic Microwave Background (CMB) temperature fluctuations are a powerful tool for testing theories of the early Universe and for measuring cosmological parameters. We present basics of CMB physics, review some of the…

Astrophysics · Physics 2007-05-23 Jean-Christophe Hamilton

The atmosphere is one of the most important contamination sources in the ground-based Cosmic Microwave Background (CMB) observations. In this paper, we study three kinds of filters, which are polynomial filter, high-pass filter, and Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Yi-Wen Wu , SiYu Li , Yang Liu , Zirui Zhang , Hao Liu , Hong Li

We present new methods for mapping the curl-free (E-mode) and divergence-free (B-mode) components of spin 2 signals using spin directional wavelets. Our methods are equally applicable to measurements of the polarisation of the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-02 Boris Leistedt , Jason D. McEwen , Martin Büttner , Hiranya V. Peiris

Dual-tree wavelet decompositions have recently gained much popularity, mainly due to their ability to provide an accurate directional analysis of images combined with a reduced redundancy. When the decomposition of a random process is…

Statistics Theory · Mathematics 2011-08-30 Caroline Chaux , Jean-Christophe Pesquet , Laurent Duval

We describe here an iterative method for jointly estimating the noise power spectrum from a scanning experiment's time-ordered data, together with the maximum-likelihood map. We test the robustness of this method on simulated datasets with…

Astrophysics · Physics 2007-05-23 S. Prunet , C. B. Netterfield , E. Hivon , B. P. Crill

In this work we propose a novel approach to utilize convolutional neural networks for time series forecasting. The time direction of the sequential data with spatial dimensions $D=1,2$ is considered democratically as the input of a…

Machine Learning · Computer Science 2020-01-13 Matthias Weissenbacher

We studied the WMAP temperature anisotropy data using two different methods. The derived signal gradient maps show regions with low mean gradients in structures near the ecliptic poles and higher gradient values in the wide ecliptic…

Astrophysics · Physics 2007-05-23 K. T. Chyzy , B. Novosyadlyj , M. Ostrowski

In the field of gamma-ray astronomy, irregular and noisy datasets make difficult the characterization of light-curve features in terms of statistical significance while properly accounting for trial factors associated with the search for…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Ryan Price , Stephane Vincent , Stephan LeBohec

We propose an audio-to-audio neural network model that learns to denoise old music recordings. Our model internally converts its input into a time-frequency representation by means of a short-time Fourier transform (STFT), and processes the…

Audio and Speech Processing · Electrical Eng. & Systems 2022-06-17 Yunpeng Li , Beat Gfeller , Marco Tagliasacchi , Dominik Roblek
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