English
Related papers

Related papers: FFT-PT: Reducing the two-loop large-scale structur…

200 papers

Fast Fourier Transform based phase screen simulations give accurate results only when the screen size ($G$) is much larger than the outer scale parameter ($L_0$). Otherwise, they fall short in correctly predicting both the low and high…

Instrumentation and Methods for Astrophysics · Physics 2021-06-03 Sorabh Chhabra , Jyotirmay Paul , Anamparambu N. Ramaprakash , Avinash Surendran

We develop a new way to analytically calculate loop integrals in the Effective Field Theory of Large Scale-Structure. Previous available methods show severe limitations beyond the one-loop power spectrum due to analytical challenges and…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-15 Charalampos Anastasiou , Diogo P. L. Bragança , Leonardo Senatore , Henry Zheng

The real-space density-functional perturbation theory (DFPT) for the computations of the response properties with respect to the atomic displacement and homogeneous electric field perturbation has been recently developed and implemented…

Computational Physics · Physics 2020-10-28 Honghui Shang , Wanzhen Liang , Yunquan Zhang , Jinlong Yang

We consider the most general effective field theory (EFT) Lagrangian with scalar fields and derivatives, and renormalise it to substantially higher loop order than existing results in the literature. EFT Lagrangians have phenomenological…

High Energy Physics - Phenomenology · Physics 2025-11-12 Johan Henriksson , Franz Herzog , Stefanos R. Kousvos , Jasper Roosmale Nepveu

We introduce a novel construction of a contour deformation within the framework of Loop-Tree Duality for the numerical computation of loop integrals featuring threshold singularities in momentum space. The functional form of our contour…

High Energy Physics - Phenomenology · Physics 2020-11-24 Zeno Capatti , Valentin Hirschi , Dario Kermanschah , Andrea Pelloni , Ben Ruijl

Linear scaling density functional theory approaches to electronic structure are often based on the tendency of electrons to localize even in large atomic and molecular systems. However, in many cases of actual interest, for example in…

Chemical Physics · Physics 2022-03-25 Marcel David Fabian , Ben Shpiro , Roi Baer

We compute the non-Gaussian contribution to the covariance of the matter power spectrum at one-loop order in Standard Perturbation Theory (SPT), and using the framework of the effective field theory (EFT) of large scale structure (LSS). The…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Daniele Bertolini , Katelin Schutz , Mikhail P. Solon , Jonathan R. Walsh , Kathryn M. Zurek

Light field (LF) images containing information for multiple views have numerous applications, which can be severely affected by low-light imaging. Recent learning-based methods for low-light enhancement have some disadvantages, such as a…

Computer Vision and Pattern Recognition · Computer Science 2023-08-16 Shansi Zhang , Nan Meng , Edmund Y. Lam

In many mechanical, electrical, and general physical systems evolving over time or space, spectral analysis methods as Fast Fourier Transform (FFT), Short Term Fourier Transform (STFT), Power Spectrum Density (PSD) plays a very important…

Signal Processing · Electrical Eng. & Systems 2023-06-21 Andreas Tuor , Nico Canzani , Tobias Rüggeberg , Stefan Gorenflo , Gerd Simons , Bruno Bättig , Daniel Iseli

Applying a transformation to a non-Gaussian field can enhance the information content of the resulting power spectrum, by reducing the correlations between Fourier modes. In the context of weak gravitational lensing, it has been shown that…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Fergus Simpson , Joachim Harnois-Déraps , Catherine Heymans , Raul Jimenez , Benjamin Joachimi , Licia Verde

We study the growth of structures in modified gravity models where the Poisson equation and the relationship between the two Newtonian potentials are modified by explicit functions of space and time. This parameterisation applies to the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 Philippe Brax , Patrick Valageas

We explore features of redshift distortion in Fourier analysis of N-body simulations. The phases of the Fourier modes of the dark matter density fluctuation are generally shifted by the peculiar motion along the line of sight, the induced…

Astrophysics · Physics 2014-10-13 Yan-Chuan Cai , Jun Pan

An integrated photonic circuit architecture to perform a modified-convolution operation based on the Discrete Fractional Fourier Transform (DFrFT) is introduced. This is accomplished by utilizing two nonuniformly-coupled waveguide lattices…

Optics · Physics 2025-02-25 Kevin Zelaya , Mohammad-Ali Miri

Though Fourier Transforms (FTs) are a common technique for finding correlation functions, they are not typically used in computations of the anisotropy of the two-point correlation function (2PCF) about the line of sight in wide-angle…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 Zachary Slepian , Daniel J. Eisenstein

If the phase retrieval problem can be solved by a method similar to that of solving a system of linear equations under the context of FFT, the time complexity of computer based phase retrieval algorithm would be reduced. Here I present such…

Numerical Analysis · Mathematics 2013-05-20 Yuan Sun

Extracting cosmological information from Stage IV weak lensing surveys requires non-linear modelling of the matter power spectrum that is accurate across a broad range of scales and redshifts and robust to baryonic feedback. We forecast the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-16 Evan Saraivanov , Henrique Rubira , Vivian Miranda , Tim Eifler

Fast Fourier transform based estimators are formulated for measuring momentum power spectra, including the auto power spectra of the momentum, the momentum divergence, and the cross spectrum of density fluctuation and momentum divergence.…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-30 Jun Pan

We present an algorithm for quickly generating multiple realizations of N-body simulations to be used, for example, for cosmological parameter estimation from surveys of large-scale structure. Our algorithm uses a new method to resample the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael D. Schneider , Shaun Cole , Carlos S. Frenk , Istvan Szapudi

Recent developments of Perturbation Theory (PT), specifically the Effective Field Theory of Large Scale Structure (EFTofLSS) and its equivalents, have proven powerful in analyzing galaxy clustering statistics such as the galaxy power…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-22 Joseph Tomlinson , Donghui Jeong