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Related papers: The Divergence-Free Radiant Transform

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This work presents a high-fidelity computational fluid dynamics (CFD) and data-driven modeling framework for assembly-level flow characterization in a four-loop pressurized water reactor (PWR). A full lower-plenum and core-inlet domain was…

We establish the theoretical foundations for embedding a correlated wave function in an environment formed by Kohn-Sham orbitals. We show that introducing an approximation which equates two, in principle distinct, kinetic-energy functionals…

Chemical Physics · Physics 2026-03-06 Enzo Monino , Daria Drwal , Michał Hapka , Libor Veis , Katarzyna Pernal

We study the problem of constructing a graph Fourier transform (GFT) for directed graphs (digraphs), which decomposes graph signals into different modes of variation with respect to the underlying network. Accordingly, to capture low,…

Spectral Theory · Mathematics 2017-06-01 Rasoul Shafipour , Ali Khodabakhsh , Gonzalo Mateos , Evdokia Nikolova

It has long been postulated that within density-functional theory (DFT) the total energy of a finite electronic system is convex with respect to electron count, so that 2 E_v[N_0] <= E_v[N_0 - 1] + E_v[N_0 + 1]. Using the…

Chemical Physics · Physics 2023-12-25 Andrew C. Burgess , Edward Linscott , David D. O'Regan

We discuss efficient algorithms for the accurate forward and reverse evaluation of the discrete Fourier-Bessel transform (dFBT) as numerical tools to assist in the 2D polar convolution of two radially symmetric functions, relevant, e.g., to…

Computational Physics · Physics 2016-11-08 O. Melchert , M. Wollweber , B. Roth

We develop the basic building blocks of a frequency domain framework for drawing statistical inferences on the second-order structure of a stationary sequence of functional data. The key element in such a context is the spectral density…

Statistics Theory · Mathematics 2013-05-10 Victor M. Panaretos , Shahin Tavakoli

Density functional theory (DFT) is an efficient instrument for describing a wide range of nanoscale phenomena: wetting transition, capillary condensation, adsorption, etc. In this paper, we suggest a method for obtaining the equilibrium…

Computational Physics · Physics 2021-06-18 Yuriy Kanygin , Irina Nesterova , Pavel Lomovitskiy , Aleksey Khlyupin

The frequency-dependent optical spectrum is pivotal for a broad range of applications, from material characterization to optoelectronics and energy harvesting. Data-driven surrogate models, trained on density functional theory (DFT) data,…

Chemical Physics · Physics 2024-07-11 Akram Ibrahim , Can Ataca

We consider finite approximations of a fractal generated by an iterated function system of affine transformations on $\mathbb{R}^d$ as a discrete set of data points. Considering a signal supported on this finite approximation, we propose a…

Functional Analysis · Mathematics 2016-07-14 Calvin Hotchkiss , Eric S. Weber

Many-body functionals of the Green's function can provide fundamental advances in electronic-structure calculations, due to their ability to accurately predict both spectral and thermodynamic properties, such as angle-resolved photoemission…

Strongly Correlated Electrons · Physics 2025-08-26 Tommaso Chiarotti , Matteo Quinzi , Andrea Pintus , Mario Caserta , Andrea Ferretti , Nicola Marzari

In this paper, we present a fast divergence-free spectral algorithm (FDSA) for the curl-curl problem. Divergence-free bases in two and three dimensions are constructed by using the generalized Jacobi polynomials. An accurate spectral method…

Numerical Analysis · Mathematics 2023-08-25 Lechang Qin , Changtao Sheng , Zhiguo Yang

The symplectic wavelet transformation [Opt. Lett. 31 (2006) 3432], which is related to quantum optical Fresnel transform, is developed to the symplectic-dilation mixed wavelet transform (SDWT). The SDWT involves both a real-variable…

Quantum Physics · Physics 2009-11-13 Hong-yi Fan , Shu-guang Liu , Li-yun Hu

We propose a decoupled divergence-free neural networks basis (Decoupled-DFNN) method for solving incompressible flow problems, including the Stokes and Navier-Stokes equations. To ensure the divergence free property exactly, the velocity…

Numerical Analysis · Mathematics 2026-03-19 Jinbao Cheng , Jianguo Huang , Haoqin Wang , Tao Zhou

How could the Fourier and other transforms be naturally discovered if one didn't know how to postulate them? In the case of the Discrete Fourier Transform (DFT), we show how it arises naturally out of analysis of circulant matrices. In…

Signal Processing · Electrical Eng. & Systems 2022-04-27 Bassam Bamieh

Density functional theory (DFT) embedding provides a formally exact framework for interfacing correlated wave-function theory (WFT) methods with lower-level descriptions of electronic structure. Here, we report techniques to improve the…

Chemical Physics · Physics 2015-06-12 Jason D. Goodpaster , Taylor A. Barnes , Frederick R. Manby , Thomas F. Miller

This paper presents a point-wise divergence-free projection method for numerical approximations of photonic quasicrystals problems. The original three-dimensional quasiperiodic Maxwell's system is transformed into a periodic one in higher…

Numerical Analysis · Mathematics 2024-09-10 Zixuan Gao , Zhenli Xu , Zhiguo Yang

Fully Developed Turbulence (FDT) is a theoretical asymptotic phenomenon which can only be approximated experimentally or computationally, so its defining characteristics are hypothetical. It is considered to be a chaotic stationary flow…

Fluid Dynamics · Physics 2014-09-23 József Vass

The recent history of optical design saw a progressive trend of also designing without rotational symmetry, especially spectrometers due to the use of reflective and diffractive elements in their designs. A freeform hyperspectral imager…

Optics · Physics 2024-07-10 Yuxuan Liu

In medical imaging, the diffusion models have shown great potential for synthetic image generation tasks. However, these approaches often lack the interpretable connections between the generated and real images and can create anatomically…

Image and Video Processing · Electrical Eng. & Systems 2026-02-12 Jian-Qing Zheng , Yuanhan Mo , Yang Sun , Jiahua Li , Fuping Wu , Ziyang Wang , Tonia Vincent , Bartłomiej W. Papież

The design of better exchange-correlation functionals for Density Functional Theory (DFT) is a central challenge of modern electronic structure theory. However, current developments are limited by the mathematical form of the functional,…

Chemical Physics · Physics 2024-08-19 Kyle Bystrom , Boris Kozinsky