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Galaxies are arranged in interconnected walls and filaments forming a cosmic web encompassing huge, nearly empty, regions between the structures. Many statistical methods have been proposed in the past in order to describe the galaxy…

Astrophysics · Physics 2016-02-17 J-L. Starck , V. J. Martinez , D. L. Donoho , O. Levi , P. Querre , E. Saar

We investigate the power of wavelet techniques in detecting non-Gaussianity in the cosmic microwave background (CMB). We use the method to discriminate between an inflationary and a cosmic strings model using small simulated patches of the…

Astrophysics · Physics 2011-05-10 R. B. Barreiro , M. P. Hobson

Standard cosmic microwave background (CMB) analyses constrain cosmological and astrophysical parameters by fitting parametric models to multifrequency power spectra (MFPS). However, such methods do not optimally weight maps in power…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Kristen M. Surrao , J. Colin Hill

In this study, we perform some analysis for the probability distributions in the space of frequency and time variables. However, in the domain of high frequencies, it behaves in such a way as the highly non-linear dynamics. The wavelet…

General Finance · Quantitative Finance 2024-11-22 Tatsuru Kikuchi

The data from Cosmic Microwave Background (CMB) experiments are becoming more complex with each new experiment. A consistent way of analysing these data sets is required so that direct comparison is possible between the various experimental…

Astrophysics · Physics 2007-05-23 A. W. Jones

This chapter is dedicated to recent developments in the field of wavelet analysis for scattered data. We introduce the concept of samplets, which are signed measures of wavelet type and may be defined on sets of arbitrarily distributed data…

Numerical Analysis · Mathematics 2025-03-25 Helmut Harbrecht , Michael Multerer

We consider the 2D wavelet transform with two scales to study sky maps of temperature anisotropies in the cosmic microwave background radiation (CMB). We apply this technique to simulated maps of small sky patches of size 12.8 \times 12.8…

We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Nicoletta Krachmalnicoff , Maurizio Tomasi

The large amount of cosmological data already available (and in the near future) makes necessary the development of efficient numerical codes. Many software products have been implemented to perform cosmological analyses considering one or…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-16 Sandro Dias Pinto Vitenti , Mariana Penna-Lima

Time series data analysis is a critical component in various domains such as finance, healthcare, and meteorology. Despite the progress in deep learning for time series analysis, there remains a challenge in addressing the non-stationary…

Machine Learning · Computer Science 2025-09-12 Han Yu , Peikun Guo , Akane Sano

Wavelets provide the flexibility to analyse stochastic processes at different scales. Here, we apply them to multivariate point processes as a means of detecting and analysing unknown non-stationarity, both within and across data streams.…

Methodology · Statistics 2020-11-04 Edward A. K. Cohen , Alexander J. Gibberd

Cosmological emulation of observables such as the Cosmic Microwave Background (CMB) spectra and matter power spectra have become increasingly common in recent years because of the potential for saving computation time in connection with…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-22 Luca Janken , Steen Hannestad , Thomas Tram , Andreas Nygaard

Abstract. Detecting anomalies in patterns of sensor data is important in many practical applications, including domestic activity monitoring for Active Assisted Living (AAL). How to represent and analyse these patterns, however, remains a…

Artificial Intelligence · Computer Science 2024-01-23 Manuel Fernandez-Carmona , Sariah Mghames , Nicola Bellotto

Extragalactic foregrounds in cosmic microwave background (CMB) observations are both a source of cosmological and astrophysical information and a nuisance to the CMB. Effective field-level modeling that captures their non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-19 M. Mebratu , W. L. K. Wu

Wavelet based algorithms in numerical analysis are similar to other transform methods in that vectors and operators are expanded into a basis and the computations take place in this new system of coordinates. However, due to the recursive…

comp-gas · Physics 2008-02-03 G. Beylkin

The Cosmic Microwave Background (CMB) is an abundant source of cosmological information. However, this information is encoded in non-trivial ways in a signal that is difficult to observe. The resulting challenges in extracting this…

Astrophysics · Physics 2014-10-13 Benjamin D. Wandelt

Wavelet analysis and compression tools are reviewed and different applications to study MHD and plasma turbulence are presented. We introduce the continuous and the orthogonal wavelet transform and detail several statistical diagnostics…

Plasma Physics · Physics 2015-10-21 Marie Farge , Kai Schneider

The cosmic microwave background (CMB) stands as a pivotal source for studying weak gravitational lensing. While the lensed CMB aids in constraining cosmological parameters, it simultaneously smooths the original CMB's features. The angular…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-17 Shulei Ni , Yichao Li , Xin Zhang

A wavelet-based method for compression of three-dimensional simulation data is presented and its software framework is described. It uses wavelet decomposition and subsequent range coding with quantization suitable for floating-point data.…

Computational Physics · Physics 2022-01-06 Dmitry Kolomenskiy , Ryo Onishi , Hitoshi Uehara

Quaternion wavelets are redundant wavelet transforms generalizing complex-valued non-decimated wavelet transforms. In this paper we propose a matrix-formulation for non-decimated quaternion wavelet transforms and define spectral tools for…

Applications · Statistics 2019-03-05 Taewoon Kong , Brani Vidakovic