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We consider the problem of estimating the covariance matrix of a random signal observed through unknown translations (modeled by cyclic shifts) and corrupted by noise. Solving this problem allows to discover low-rank structures masked by…

Statistics Theory · Mathematics 2020-11-11 Boris Landa , Yoel Shkolnisky

We determine the asymptotic density $\delta_k$ of the set of ordered $k$-tuples $(n_1,...,n_k)\in \N^k, k\ge 2$, such that there exists no prime power $p^a$, $a\ge 1$, appearing in the canonical factorization of each $n_i$, $1\le i\le k$,…

Number Theory · Mathematics 2007-05-23 László Tóth

We propose a generic Scattering Power Factorization Framework (SPFF) for Polarimetric Synthetic Aperture Radar (PolSAR) data to directly obtain $N$ scattering power components along with a residue power component for each pixel. Each…

Signal Processing · Electrical Eng. & Systems 2025-05-27 Debanshu Ratha , Eric Pottier , Avik Bhattacharya , Alejandro C. Frery

Measuring the clustering of galaxies from surveys allows us to estimate the power spectrum of matter density fluctuations, thus constraining cosmological models. This requires careful modelling of observational effects to avoid…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-26 Daniele Sorini

We propose a method for recovering the shape of the mass power spectrum on large scales from the transmission fluctuations of the Lyman-alpha forest, which takes into account directly redshift-space distortions. The procedure, in…

Astrophysics · Physics 2009-10-30 Lam Hui

Images taken with modern detectors require calibration via flat fielding to obtain the same flux scale across the whole image. One method for obtaining the best possible flat fielding accuracy is to derive a photometric model from dithered…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Lodovico Coccato , Daniel M. Bramich , Wolfram Freudling , Sabine Moehler

In this paper, we consider a method for fast numerical computation of the Fourier transform of a slowly decaying function with given accuracy in given ranges of the frequency. In these decades, some useful formulas for the Fourier transform…

Numerical Analysis · Mathematics 2015-07-28 Ken'ichiro Tanaka

Delay-and-sum (DAS) algorithms are widely used for beamforming in linear array photoacoustic imaging systems and are characterized by fast execution. However, these algorithms suffer from various drawbacks like low resolution, low contrast,…

Medical Physics · Physics 2021-07-29 Souradip Paul , Subhamoy Mandal , Mayanglambam Suheshkumar Singh

An inverse nonequispaced fast Fourier transform (iNFFT) is a fast algorithm to compute the Fourier coefficients of a trigonometric polynomial from nonequispaced sampling data. However, various applications such as magnetic resonance imaging…

Numerical Analysis · Mathematics 2025-06-09 Melanie Kircheis , Daniel Potts

The role played by zero-point contribution, also called quantum noise or vacuum fluctuations, in the quantum expression of the fluctuation-dissipation theorem (FDT) is a long-standing open problem widely discussed by the physicist community…

Other Condensed Matter · Physics 2017-10-31 Lino Reggiani , Eleonora Alfinito

The relation between the pion's quark distribution function, $q(x)$, its light-front wave function, and the elastic charge form factor, $F(\Delta^2)$ is explored. The square of the leading-twist pion wave function at a special probe scale,…

High Energy Physics - Phenomenology · Physics 2024-03-07 Mary Alberg , Gerald A. Miller

Recently, a new polynomial basis over binary extension fields was proposed such that the fast Fourier transform (FFT) over such fields can be computed in the complexity of order $\mathcal{O}(n\lg(n))$, where $n$ is the number of points…

Information Theory · Computer Science 2016-08-16 Sian-Jheng Lin , Tareq Y. Al-Naffouri , Yunghsiang S. Han

We discuss an analytical approximation for the matter power spectrum covariance matrix and its inverse on translinear scales, $k \sim 0.1h - 0.8h/\textrm{Mpc}$ at $z = 0$. We proceed to give an analytical expression for the Fisher…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Julien Carron , Melody Wolk , István Szapudi

In this paper, we focus on the approximation of smooth functions $f: [-\pi, \pi] \rightarrow \mathbb{C}$, up to an unresolvable global phase ambiguity, from a finite set of Short Time Fourier Transform (STFT) magnitude (i.e., spectrogram)…

Numerical Analysis · Mathematics 2021-06-07 Mark Iwen , Michael Perlmutter , Nada Sissouno , Aditya Viswanathan

Automatic Music Transcription (AMT) consists in automatically estimating the notes in an audio recording, through three attributes: onset time, duration and pitch. Probabilistic Latent Component Analysis (PLCA) has become very popular for…

Machine Learning · Statistics 2017-04-07 D. Cazau , G. Revillon , W. Yuancheng , O. Adam

The graph fractional Fourier transform (GFRFT) for unitary graph Fourier transform (GFT) matrices can be interpreted through the scalar function $e^{j\alpha\theta}$ on the unit circle. Under the principal branch, its Fourier-series…

Signal Processing · Electrical Eng. & Systems 2026-05-19 Ziqi Yan , Mingzhi Wang , Sen Shi , Feiyue Zhao , Manjun Cui , Yangfan He , Zhichao Zhang

We introduce a new method for Estimation of Signal Parameters based on Iterative Rational Approximation (ESPIRA) for sparse exponential sums. Our algorithm uses the AAA algorithm for rational approximation of the discrete Fourier transform…

Numerical Analysis · Mathematics 2022-01-07 Nadiia Derevianko , Gerlind Plonka , Markus Petz

Generalized gradient approximated (GGA) density functional theory (DFT) typically overestimates polarizability and bond-lengths, and underestimates force constants of covalent bonds. To overcome this problem we show that one can use…

Chemical Physics · Physics 2016-06-29 O. Anatole von Lilienfeld

Regenerated (FRF curves), synthesis of (FRF) curves there are two main requirement in the form of response model, The first being that of regenerating "Theoretical" curve for the frequency response function actually measured and analysis…

Computational Engineering, Finance, and Science · Computer Science 2012-08-21 Hisham A. H. Al-Khazali , Mohamad R. Askari

Fluctuations in the large-scale structure of the Universe contain significant information about cosmological physics, but are modulated in survey datasets by various observational effects. Building on existing literature, we provide a…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Chris Blake
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