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The solution of the Lippman-Schwinger (L-S) integral equation is equivalent to the the solution of the Schroedinger equation. A new numerical algorithm for solving the L-S equation is described in simple terms, and its high accuracy is…

Computational Physics · Physics 2007-05-23 G. H. Rawitscher , I. Koltracht

In his monograph Chebyshev and Fourier Spectral Methods, John Boyd claimed that, regarding Fourier spectral methods for solving differential equations, ``[t]he virtues of the Fast Fourier Transform will continue to improve as the relentless…

Numerical Analysis · Mathematics 2023-02-03 Craig Gross , Mark Iwen

Unconstrained partial-wave amplitudes obtained at discrete energies from fits to complete sets of eight independent observables which are required to uniquely reconstruct reaction amplitudes do not vary smoothly with energy, and are in…

We use several techniques to probe the wave functions proposed to describe the ${\cal A}$ phases by Das, Das, and Mandal [Phys. Rev. Lett. 131, 056202 (2023); Phys. Rev. Lett. 132, 106501 (2024); Phys. Rev. B 110, L121303 (2024).]. As…

Strongly Correlated Electrons · Physics 2024-10-18 Steven H. Simon , Ajit C. Balram

We calculate the spectral density of the phi meson in a hot bath of nucleons and pions using a general formalism relating self-energy to the forward scattering amplitude (FSA). In order to describe the low energy FSA, we use experimental…

Nuclear Theory · Physics 2011-08-11 G. Vujanovic , J. Ruppert , C. Gale

A variational approach to reconstruction of phase and amplitude of a complex-valued object from Poissonian intensity observations is developed. The observation model corresponds to the typical optical setups with a phase modulation of…

Numerical Analysis · Computer Science 2017-09-06 Vladimir Katkovnik

Chebyshev pseudospectral (PS) methods are reported to provide highly accurate solution using polynomial approximation. Use of polynomial basis functions in PS algorithms limits the formulation to univariate systems constraining it to tensor…

Computational Physics · Physics 2015-12-01 Pankaj K Mishra , Sankar K Nath

In this work, the phase function method (PFM) is employed for the first time to explicitly construct scattering wavefunctions for the $\alpha\alpha$ system using a single-term Morse potential. Unlike earlier PFM-based studies that primarily…

Nuclear Theory · Physics 2026-02-24 Anil Khachi , Shikha Awasthi , Tarachand Verma , Ranjana Joshi

Solving an acoustic wave equation using a parabolic approximation is a popular approach for many existing ocean acoustic models. Commonly used parabolic equation (PE) model programs, such as the range-dependent acoustic model (RAM), are…

Computational Engineering, Finance, and Science · Computer Science 2021-06-02 Houwang Tu , Yongxian Wang , Xian Ma , Xunjiang Zhu

The general method to obtain solutions of the Maxwellian equations from scalar representatives is developed and applied to the diffraction of electromagnetic waves. Kirchhoff's integral is modified to provide explicit expressions for these…

Optics · Physics 2019-03-27 Ulrich Brosa

[NOTE: Previous versions of this paper (both on astro-ph and published in Phys. Rev. D) contain results that are in error. The power spectra C_l were normalized incorrectly by a factor of 2 pi. All observing times in detector-years in those…

Astrophysics · Physics 2008-11-26 Emory F. Bunn

We apply the stationary phase method developed in (Assier, Shanin \& Korolkov, QJMAM, 76(1), 2022) to the problem of wave diffraction by a quarter-plane. The wave field is written as a double Fourier transform of an unknown spectral…

Analysis of PDEs · Mathematics 2023-10-30 Raphael C. Assier , Andrey V. Shanin , Andrey I. Korolkov

Multi-channel phase space with a single Feynman diagram enhancement is a powerful tool for high-energy physics event generation if a diagram with a singular propagator dominates the total scattering amplitude at the corresponding singular…

High Energy Physics - Phenomenology · Physics 2026-03-03 Kaoru Hagiwara , Junichi Kanzaki , Fabio Maltoni , Kentarou Mawatari , Ya-Juan Zheng

We present a novel spectral method for the Allen-Cahn equation on spheres, eliminating the reliance on conventional quadrature exactness conditions. By replacing these conditions with a restricted isometry relation derived from…

Numerical Analysis · Mathematics 2025-08-20 Hao-Ning Wu , Xiaoming Yuan

The stepwise coupled-mode model is a classic approach for solving range-dependent sound propagation problems. Existing coupled-mode programs have disadvantages such as high computational cost, weak adaptability to complex ocean environments…

Computational Physics · Physics 2023-03-14 Houwang Tu , Yongxian Wang , Chunmei Yang , Wei Liu , Wenbin Xiao , Xiaodong Wang

The f-electron spectral function of the Falicov-Kimball model is calculated via a Keldysh-based many-body formalism originally developed by Brandt and Urbanek. We provide results for both the Bethe lattice and the hypercubic lattice at half…

Strongly Correlated Electrons · Physics 2009-11-10 J. K. Freericks , V. Turkowski , V. Zlatic

In this work, we present a computationally efficient methodology that utilizes a local real-space formulation of the projector augmented wave (PAW) method discretized with a finite-element (FE) basis to enable accurate and large-scale…

Computational Physics · Physics 2025-01-03 Kartick Ramakrishnan , Sambit Das , Phani Motamarri

Phase retrieval refers to the problem of recovering a signal $\mathbf{x}_{\star}\in\mathbb{C}^n$ from its phaseless measurements $y_i=|\mathbf{a}_i^{\mathrm{H}}\mathbf{x}_{\star}|$, where $\{\mathbf{a}_i\}_{i=1}^m$ are the measurement…

Information Theory · Computer Science 2020-09-10 Junjie Ma , Rishabh Dudeja , Ji Xu , Arian Maleki , Xiaodong Wang

The calculation of a three-dimensional underwater acoustic field has always been a key problem in computational ocean acoustics. Traditionally, this solution is usually obtained by directly solving the acoustic Helmholtz equation using a…

Computational Physics · Physics 2022-11-14 Houwang Tu , Yongxian Wang , Wei Liu , Chunmei Yang , Jixing Qin , Shuqing Ma , Xiaodong Wang

Kinetic models provide highly accurate descriptions of plasma waves but involve complex integrals that are computationally expensive to solve. To facilitate a fluid-like treatment of the system, we propose rational approximations for both…

Plasma Physics · Physics 2025-08-13 Huasheng Xie