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Spectral computed tomography (CT) is an emerging technology capable of providing high chemical specificity, which is crucial for many applications such as detecting threats in luggage. This type of application requires both fast and…

Image and Video Processing · Electrical Eng. & Systems 2021-03-30 Wail Mustafa , Christian Kehl , Ulrik Lund Olsen , Søren Kimmer Schou Gregersen , David Malmgren-Hansen , Jan Kehres , Anders Bjorholm Dahl

For a function that is analytic on and around an interval, Chebyshev polynomial interpolation provides spectral convergence. However, if the function has a singularity close to the interval, the rate of convergence is near one. In these…

Numerical Analysis · Mathematics 2017-08-10 Kevin W. Aiton , Tobin A. Driscoll

Spectral computed tomography based on a photon-counting detector (PCD) attracts more and more attentions since it has the capability to provide more accurate identification and quantitative analysis for biomedical materials. The limited…

Image and Video Processing · Electrical Eng. & Systems 2023-11-17 Xiaodong Guo , Longhui Li , Dingyue Chang , Peng He , Peng Feng , Hengyong Yu , Weiwen Wu

Machine learning has made important headway in helping to improve the treatment of quantum many-body systems. A domain of particular relevance are correlated inhomogeneous systems. What has been missing so far is a general, scalable…

Quantum Physics · Physics 2026-02-10 Alex Blania , Sandro Herbig , Fabian Dechent , Evert van Nieuwenburg , Florian Marquardt

A spectral element method (SEM) is developed to solve polarized radiative transfer in multidimensional participating medium. The angular discretization is based on the discrete-ordinates approach, and the spatial discretization is conducted…

Computational Physics · Physics 2011-05-09 J. M. Zhao , L. H. Liu , P. -f. Hsu , J. Y. Tan

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

Quantum embedding methods have become a powerful tool to overcome deficiencies of traditional quantum modelling in materials science. However, while these are systematically improvable in principle, in practice it is rarely possible to…

Strongly Correlated Electrons · Physics 2022-11-02 Max Nusspickel , George H. Booth

The purpose of this study is to utilize the Chebyshev spectral method neural network(CSNN) model to solve differential equations. This approach employs a single-layer neural network wherein Chebyshev spectral methods are used to construct…

Numerical Analysis · Mathematics 2024-07-08 Pengsong Yin , Shuo Ling , Wenjun Ying

A recently re-discovered variant of the Backus-Gilbert algorithm for spectral reconstruction enables the controlled determination of smeared spectral densities from lattice field theory correlation functions. A particular advantage of this…

High Energy Physics - Lattice · Physics 2023-01-11 John Bulava

We implement an algorithm which is aimed to reduce the number of basis states spanning the Hilbert space of quantum many-body systems. We test the efficiency of the procedure by working out and analyzing the spectral properties of strongly…

Quantum Physics · Physics 2007-05-23 Tarek Khalil , Jean Richert

Dynamic density-matrix renormalization provides valuable numerical information on dynamic correlations by computing convolutions of the corresponding spectral densities. Here we discuss and illustrate how and to which extent such data can…

Strongly Correlated Electrons · Physics 2007-05-23 Carsten Raas , Götz S. Uhrig

In typical microscopic approaches, particularly when pairing correlations are present, nuclei and nuclear fragments do not have well defined quantum numbers and symmetries should be restored. I present here a formalism for the simultaneous…

Nuclear Theory · Physics 2021-11-03 Aurel Bulgac

Resonant spectroscopies, which involve intermediate states with finite lifetimes, provide essential insights into collective excitations in quantum materials that are otherwise inaccessible. However, theoretical understanding in this area…

Strongly Correlated Electrons · Physics 2025-09-30 Prakash Sharma , Luogen Xu , Fei Xue , Yao Wang

While historically many quantum mechanical simulations of molecular dynamics have relied on the Born-Oppenheimer approximation to separate electronic and nuclear behavior, recently a lot of interest has arisen towards quantum effects in…

Quantum Physics · Physics 2018-06-06 Simone Sturniolo

I present an algorithm for the reconstruction of multivariate rational functions from black-box probes. The arguably most important application in high-energy physics is the calculation of multi-loop and multi-leg amplitudes, where rational…

High Energy Physics - Phenomenology · Physics 2025-09-11 Andreas Maier

We compute the spectral functions for the two-site dynamical cluster theory and for the two-orbital dynamical mean-field theory in the density-matrix renormalization group (DMRG) framework using Chebyshev expansions represented with matrix…

Strongly Correlated Electrons · Physics 2014-09-18 F. Alexander Wolf , Ian P. McCulloch , Olivier Parcollet , Ulrich Schollwöck

Switching between different levels of resolution is essential for multiscale modeling, but restoring details at higher resolution remains challenging. In our previous study we have introduced deepBackmap: a deep neural-network-based…

Chemical Physics · Physics 2024-06-12 Marc Stieffenhofer , Tristan Bereau , Michael Wand

Density-functional theory (DFT) has revolutionized computer simulations in chemistry and material science. A faithful implementation of the theory requires self-consistent calculations. However, this effort involves repeatedly diagonalizing…

Quantum Physics · Physics 2023-07-17 Taehee Ko , Xiantao Li , Chunhao Wang

Density matrix embedding theory (DMET) [Phys. Rev. Lett., 109, 186404 (2012)], introduced a new approach to quantum cluster embedding methods, whereby the mapping of strongly correlated bulk problems to an impurity with finite set of bath…

Strongly Correlated Electrons · Physics 2015-06-24 George H. Booth , Garnet Kin-Lic Chan

Multidimensional NMR spectroscopy is one of the basic tools for determining the structure of biomolecules. Unfortunately, the resolution of the spectra is often limited by inter-nuclear couplings. This limitation cannot be overcome by…