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Sparse variational approximations are popular methods for scaling up inference and learning in Gaussian processes to larger datasets. For $N$ training points, exact inference has $O(N^3)$ cost; with $M \ll N$ features, state of the art…

Machine Learning · Statistics 2024-04-15 Talay M Cheema , Carl Edward Rasmussen

We present an ab-initio density-functional-theory approach for calculating electron-phonon interactions within the projector augmented-wave method. The required electron-phonon matrix elements are defined as the second derivative of the…

Materials Science · Physics 2020-05-06 Manuel Engel , Martijn Marsman , Cesare Franchini , Georg Kresse

We consider an initial-boundary value problem for the $n$-dimensional wave equation with the variable sound speed, $n\geq 1$. We construct three-level implicit in time and compact in space (three-point in each space direction) 4th order…

Numerical Analysis · Mathematics 2026-01-01 Alexander Zlotnik , Raimondas Čiegis

In the Projector Augmented Wave (PAW) method, a local potential, basis functions, and projector functions form an All-Electron (AE) basis for valence wave functions in the application of Density Functional Theory (DFT). The construction of…

Materials Science · Physics 2010-08-05 R. J. Snow , A. F. Wright , C. Y. Fong

The central object in wave turbulence theory is the wave kinetic equation (WKE), which is an evolution equation for wave action density and acts as the wave analog of the Boltzmann kinetic equations for particle interactions. Despite recent…

Numerical Analysis · Mathematics 2026-04-21 Kunlun Qi , Lian Shen , Li Wang

A method based on the Fast Fourier Transform is proposed to obtain the dispersion relation of acoustic waves in heterogeneous periodic media with arbitrary microstructures. The microstructure is explicitly considered using a voxelized…

Materials Science · Physics 2021-06-24 J. Segurado , R. A. Lebensohn

We demonstrate a highly efficient GPU implementation of the Wannier interpolation of electron-phonon matrix elements in the EPW code. Building on a systematic analysis of the computational complexity of the algorithm for electron-phonon…

Materials Science · Physics 2026-03-12 Tae Yun Kim , Zhe Liu , Sabyasachi Tiwari , Elena R. Margine , Feliciano Giustino

This paper is devoted to a numerical analysis of a fractional viscoelastic wave propagation model that generalizes the fractional Maxwell model and the fractional Zener model. First, we convert the model problem into a velocity type…

Numerical Analysis · Mathematics 2025-07-17 Hao Yuan , Xiaoping Xie

Manipulating the dispersive characteristics of vibrational waves is beneficial for many applications, e.g., high-precision instruments. architected hierarchical phononic materials have sparked promise tunability of elastodynamic waves and…

Accurate large-scale Kohn-Sham density functional theory (DFT) calculations are essential for modeling complex material systems, including interfaces, defects, nanoclusters, and twisted two-dimensional heterostructures. Achieving chemical…

Computational Physics · Physics 2026-04-30 Kartick Ramakrishnan , Phani Motamarri

Phonons play a critical role in determining various material properties, but conventional methods for phonon calculations are computationally intensive, limiting their broad applicability. In this study, we present an approach to accelerate…

Materials Science · Physics 2024-07-16 Huiju Lee , Vinay I. Hegde , Chris Wolverton , Yi Xia

A mixed basis all-electron full-potential method, which uses two kinds of augmented waves, the augmented plane waves and the muffin-tin orbitals simultaneously, in addition to the local orbitals, was proposed by Kotani and van Schilfgaarde…

Materials Science · Physics 2015-02-10 Takao Kotani , Hiori Kino , Hisazumi Akai

The Projected Augmented Waves (PAW) method is based on a linear transformation between the pseudo wavefunctions and the all electron wavefunctions. To obtain high accuracy with this method, it is important that the local part of the linear…

Other Condensed Matter · Physics 2025-04-15 Garry Goldstein

In this paper, we compute the band structure of one- and two-dimensional phononic composites using the extended finite element method (X-FEM) on structured higher-order (spectral) finite element meshes. On using partition-of-unity…

Computational Physics · Physics 2021-11-09 Eric B. Chin , Amir Ashkan Mokhtari , Ankit Srivastava , N. Sukumar

We devise a mixing algorithm for full-potential (FP) all-electron calculations in the linearized augmented planewave (LAPW) method. Pulay's direct inversion in the iterative subspace is complemented with the Kerker preconditioner and…

Materials Science · Physics 2021-01-21 Jongmin Kim , Andris Gulans , Claudia Draxl

Highly oscillatory differential equations present significant challenges in numerical treatments. The Modulated Fourier Expansion (MFE), used as an ansatz, is a commonly employed tool as a numerical approximation method. In this article,…

Numerical Analysis · Mathematics 2024-07-17 Rafał Perczyński , Antoni Augustynowicz

Spectral data is routinely broadened in order to improve appearance, approximate a higher sampling level or model experimental measurement effects. While there has been extensive work in the signal processing field to develop efficient…

Materials Science · Physics 2023-09-22 Jessica Farmer , Adam J. Jackson

We begin by addressing the time-domain full-waveform inversion using the adjoint method. Next, we derive the scaled boundary semi-weak form of the scalar wave equation in heterogeneous media through the Galerkin method. Unlike conventional…

Numerical Analysis · Mathematics 2025-01-14 Alireza Daneshyar , Stefan Kollmannsberger

Variational AutoEncoder (VAE) has been extended as a representative nonlinear method for collaborative filtering. However, the bottleneck of VAE lies in the softmax computation over all items, such that it takes linear costs in the number…

Machine Learning · Computer Science 2022-05-31 Jin Chen , Defu Lian , Binbin Jin , Xu Huang , Kai Zheng , Enhong Chen

The boundary element method is an efficient algorithm for simulating acoustic propagation through homogeneous objects embedded in free space. The conditioning of the system matrix strongly depends on physical parameters such as density,…

Numerical Analysis · Mathematics 2021-12-07 Elwin van 't Wout , Seyyed R. Haqshenas , Pierre Gélat , Timo Betcke , Nader Saffari