English
Related papers

Related papers: Reconstruction in Fourier space

200 papers

A fast algorithm for the approximation of a low rank LU decomposition is presented. In order to achieve a low complexity, the algorithm uses sparse random projections combined with FFT-based random projections. The asymptotic approximation…

Numerical Analysis · Mathematics 2016-01-19 Yariv Aizenbud , Gil Shabat , Amir Averbuch

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

Noncollinear (NC) magnetism and spin-orbit coupling (SOC) are indispensable for predictive ab initio materials simulations with pronounced relativistic effects and magnetic frustration, yet they significantly increase the cost of…

Undersampled images, such as those produced by the HST WFPC-2, misrepresent fine-scale structure intrinsic to the astronomical sources being imaged. Analyzing such images is difficult on scales close to their resolution limits and may…

Astrophysics · Physics 2009-10-31 Tod R. Lauer

Using a method to correct redshift space distortion (RSD) for individual galaxies, we mapped the real space distributions of galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7). We use an ensemble of mock catalogs to…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-28 Feng Shi , Xiaohu Yang , Huiyuan Wang , Youcai Zhang , H. J. Mo , Frank C. van den Bosch , Shijie Li , Chengze Liu , Yi Lu , Dylan Tweed , Lei Yang

Many of the cosmological tests to be performed by planned dark energy experiments will require extremely well-characterized photometric redshift measurements. Current estimates are that the true mean redshift of the objects in each photo-z…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-22 Daniel J. Matthews , Jeffrey A. Newman

The reconstruction algorithm introduced by \cite{Eis07}, which is widely used in clustering analysis, is based on the inference of the first order Lagrangian displacement field from the Gaussian smoothed galaxy density field in redshift…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-09 M. Vargas-Magaña , S. Ho , S. Fromenteau , A. J. Cuesta

A near-future detection of the 21cm signal from the epoch of reionization will provide unique opportunities to probe the underlying cosmology, provided that such cosmological information can be extracted with precision. To this end, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-28 Wenzer Qin , Katelin Schutz , Aaron Smith , Enrico Garaldi , Rahul Kannan , Tracy R. Slatyer , Mark Vogelsberger

To obtain the initial pressure from the collected data on a planar sensor arrangement in photoacoustic tomography, there exists an exact analytic frequency domain reconstruction formula. An efficient realization of this formula needs to…

In this work we consider the problem of reconstruction of a signal from the magnitude of its Fourier transform, also known as phase retrieval. The problem arises in many areas of astronomy, crystallography, optics, and coherent diffraction…

Optics · Physics 2012-03-22 Eliyahu Osherovich

A fast implementation of the OPED algorithm, a reconstruction algorithm for Radon data introduced recently, is proposed and tested. The new implementation uses FFT for discrete sine transform and an interpolation step. The convergence of…

Numerical Analysis · Mathematics 2007-05-23 Yuan Xu , Oleg Tischenko

Herein, we present a deep-learning technique for reconstructing the dark-matter density field from the redshift-space distribution of dark-matter halos. We built a UNet-architecture neural network and trained it using the COmoving…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-21 Zitong Wang , Feng Shi , Xiaohu Yang , Qingyang Li , Yanming Liu , Xiaoping Li

We investigate the amount of primordial information that can be reconstructed from spectroscopic galaxy surveys, as well as what sets the noise in reconstruction at low wavenumbers, by studying a simplified universe in which galaxies are…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Matthew McQuinn

The earlier works in the context of low-rank-sparse-decomposition (LRSD)-driven stationary synthetic aperture radar (SAR) imaging have shown significant improvement in the reconstruction-decomposition process. Neither of the proposed…

Image and Video Processing · Electrical Eng. & Systems 2025-12-12 Hamid Reza Hashempour , Majid Moradikia , Hamed Bastami , Ahmed Abdelhadi , Mojtaba Soltanalian

A non-iterative method for the construction of the Short-Time Fourier Transform (STFT) phase from the magnitude is presented. The method is based on the direct relationship between the partial derivatives of the phase and the logarithm of…

Sound · Computer Science 2019-03-27 Zdeněk Průša , Peter Balazs , Peter L. Søndergaard

Accurate redshift estimates are a vital component in understanding galaxy evolution and precision cosmology. In this paper, we explore approaches to increase the applicability of machine learning models for photometric redshift estimation…

Instrumentation and Methods for Astrophysics · Physics 2026-01-27 Jonathan Soriano , Tuan Do , Srinath Saikrishnan , Vikram Seenivasan , Bernie Boscoe , Jack Singal , Evan Jones

We reconstruct the 3D matter density and peculiar velocity fields in the local Universe up to a distance of 200$\,h^{-1}\,$Mpc from the Two-Micron All-Sky Redshift Survey (2MRS), using a neural network (NN). We employed an NN with a U-net…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-01 Robert Lilow , Punyakoti Ganeshaiah Veena , Adi Nusser

Forward gradient descent (FGD) has been proposed as a biologically more plausible alternative of gradient descent as it can be computed without backward pass. Considering the linear model with $d$ parameters, previous work has found that…

Statistics Theory · Mathematics 2024-11-27 Niklas Dexheimer , Johannes Schmidt-Hieber

This paper presents novel strategies for spawning and fusing submaps within an elastic dense 3D reconstruction system. The proposed system uses spatial understanding of the scanned environment to control memory usage growth by fusing…

Robotics · Computer Science 2021-09-21 Yiduo Wang , Milad Ramezani , Matias Mattamala , Maurice Fallon

Diffusion Posterior Sampling(DPS) methodology is a novel framework that permits nonlinear CT reconstruction by integrating a diffusion prior and an analytic physical system model, allowing for one-time training for different applications.…

Image and Video Processing · Electrical Eng. & Systems 2024-07-19 Xiao Jiang , Shudong Li , Peiqing Teng , Grace Gang , J. Webster Stayman
‹ Prev 1 8 9 10 Next ›