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We forecast the benefits induced by adding the bispectrum anisotropic signal to the standard, two- and three-point, clustering statistics analysis. In particular, we forecast cosmological parameter constraints including the bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-22 Davide Gualdi , Licia Verde

The computational efficiency of many neural operators, widely used for learning solutions of PDEs, relies on the fast Fourier transform (FFT) for performing spectral computations. As the FFT is limited to equispaced (rectangular) grids,…

The Fast Fourier Transform (FFT) is one of the most widely used algorithms in high performance computing, with critical applications in spectral analysis for both signal processing and the numerical solution of partial differential…

Numerical Analysis · Mathematics 2025-05-01 Laslo Hunhold , John Gustafson

In micromagnetic simulations, the demagnetization field is by far the computationally most expensive field component and often a limiting factor in large multilayer systems. We present an exact method to calculate the demagnetization field…

Computational Physics · Physics 2020-03-18 Paul Heistracher , Florian Bruckner , Claas Abert , Christoph Vogler , Dieter Suess

Astrophysical time series often contain periodic signals. The large and growing volume of time series data from photometric surveys demands computationally efficient methods for detecting and characterizing such signals. The most efficient…

Instrumentation and Methods for Astrophysics · Physics 2021-02-09 John Hoffman , Jacob Vanderplas , Joel Hartman , Gaspar Bakos

We study the possibility of using quadrupole moments of auto-convolved galaxy images to measure cosmic shear. The autoconvolution of an image corresponds to the inverse Fourier transformation of its power spectrum. The new method has the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Xiangchong Li , Jun Zhang

Measurements of primordial non-Gaussianity ($f_{NL}$) open a new window onto the physics of inflation. We describe a fast cubic (bispectrum) estimator of $f_{NL}$, using a combined analysis of temperature and polarization observations. The…

Astrophysics · Physics 2009-02-23 Amit P. S. Yadav , Eiichiro Komatsu , Benjamin D. Wandelt

A fast full-wave simulation technique is presented for the analysis of large irregular planar arrays of identical 3-D metallic antennas. The solution method relies on the Macro Basis Functions (MBF) approach and an interpolatory technique…

Instrumentation and Methods for Astrophysics · Physics 2018-05-09 Ha Bui-Van , Jens Abraham , Michel Arts , Quentin Gueuning , Christopher Raucy , David Gonzalez-Ovejero , Eloy de Lera Acedo , Christophe Craeye

Measurements of the clustering of galaxies in Fourier space, and at low wavenumbers, offer a window into the early Universe via the possible presence of scale dependent bias generated by Primordial Non Gaussianites. On such large scales a…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-08 Emanuele Castorina , Enea di Dio

We present a fast and accurate algorithm for the evaluation of nonlocal (long-range) Coulomb and dipole-dipole interactions in free space. The governing potential is simply the convolution of an interaction kernel $U(\bx)$ and a density…

Numerical Analysis · Mathematics 2014-10-07 Shidong Jiang , Leslie Greengard , Weizhu Bao

We describe a simple and fast method to correct ellipticity measurements of galaxies from the distortion by the instrumental and atmospheric point spread function (PSF), in view of weak lensing shear measurements. The method performs a…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-01 M. Tewes , N. Cantale , F. Courbin , T. D. Kitching , G. Meylan

Since the volume accessible to galaxy surveys is fundamentally limited, it is extremely important to analyse available data in the most optimal fashion. One way of enhancing the cosmological information extracted from the clustering of…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-20 David W. Pearson , Lado Samushia , Praful Gagrani

On-going or soon to come cosmological large-scale structure surveys such as DESI, SPHEREx, Euclid, or the High-Latitude Spectroscopic Survey of the Nancy Grace Roman Space Telescope promise unprecedented measurement of the clustering of…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-02 Brandon Khek , Henry S. Grasshorn Gebhardt , Olivier Doré

The paper discusses the construction of high dimensional spatial discretizations for arbitrary multivariate trigonometric polynomials, where the frequency support of the trigonometric polynomial is known. We suggest a construction based on…

Numerical Analysis · Mathematics 2017-11-20 Lutz Kämmerer

While the simplest inflationary models predict a power-law form of the primordial power spectrum (PPS), various UV complete scenarios predict features on top of the standard power law that leave characteristic imprints in the late-time…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-26 Rodrigo Calderon , Théo Simon , Arman Shafieloo , Dhiraj Kumar Hazra

An important component of many image alignment methods is the calculation of inner products (correlations) between an image of $n\times n$ pixels and another image translated by some shift and rotated by some angle. For robust alignment of…

Numerical Analysis · Mathematics 2020-02-19 Aaditya Rangan , Marina Spivak , Joakim Andén , Alex Barnett

Rank-2 tensor fields of large-scale structure, e.g. a tensor field inferred from shapes of galaxies, open up a window to directly access 2-scalar, 2-vector and 2-tensor modes, where the scalar fields can be measured independently from the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-13 Toshiki Kurita , Masahiro Takada

We present the effective field theory studies of primordial statistical anisotropies in models of anisotropic inflation. The general action in unitary gauge is presented to calculate the leading interactions between the gauge field…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Tahereh Rostami , Asieh Karami , Hassan Firouzjahi

The $N$th power of a polynomial matrix of fixed size and degree can be computed by binary powering as fast as multiplying two polynomials of linear degree in~$N$. When Fast Fourier Transform (FFT) is available, the resulting complexity is…

Symbolic Computation · Computer Science 2023-05-29 Alin Bostan , Vincent Neiger , Sergey Yurkevich

Fractional programming (FP) arises in various communications and signal processing problems because several key quantities in the field are fractionally structured, e.g., the Cram\'{e}r-Rao bound, the Fisher information, and the…

Information Theory · Computer Science 2024-05-29 Kaiming Shen , Ziping Zhao , Yannan Chen , Zepeng Zhang , Hei Victor Cheng