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The recent development of spectral method has been praised for its high-order convergence in simulating complex physical problems. The combination of embedded boundary method and spectral method becomes a mainstream way to tackle…

Numerical Analysis · Mathematics 2018-03-08 Po-Yi Wu , Cheng-Hong Robert Kao , Tony Wen-Hann Sheu

In this paper we develop and compare different real-time methods to calculate spectral functions. These are classical-statistical simulations, the Gaussian state approximation (GSA), and the functional renormalization group (FRG) formulated…

High Energy Physics - Phenomenology · Physics 2022-06-23 Johannes V. Roth , Dominik Schweitzer , Leon J. Sieke , Lorenz von Smekal

To alleviate the computational cost associated with on-the-fly ab initio semiclassical calculations of molecular spectra, we propose the single-Hessian thawed Gaussian approximation, in which the Hessian of the potential energy at all…

Chemical Physics · Physics 2024-09-26 Tomislav Begušić , Manuel Cordova , Jiří Vaníček

We develop a framework that enables direct and meaningful comparison of two early fault-tolerant methods for the computation of eigenenergies, namely \gls{qksd} and \gls{spe}, within which both methods use expectation values of Chebyshev…

Quantum Physics · Physics 2026-03-17 Oumarou Oumarou , Pauline J. Ollitrault , Stefano Polla , Christian Gogolin

We present a new linear scaling method for the energy minimization step of semiempirical and first-principles Hartree-Fock and Kohn-Sham calculations. It is based on the self-consistent calculation of the optimum localized orbitals of any…

Materials Science · Physics 2009-11-10 Luis Seijo , Zoila Barandiaran

In this work, we propose a novel methodology for robustly estimating particle size distributions from optical scattering measurements using constrained Gaussian process regression. The estimation of particle size distributions is commonly…

Machine Learning · Statistics 2025-07-08 Fahime Seyedheydari , Mahdi Nasiri , Marcin Mińkowski , Simo Särkkä

An explicit high order semi-Lagrangian method is developed for solving Lagrangian transport equations in Eulerian-Lagrangian formulations. To ensure a semi-Lagrangian approximation that is consistent with an explicit Eulerian, discontinuous…

Numerical Analysis · Mathematics 2019-10-16 Hareshram Natarajan , Gustaaf B. Jacobs

Harnessing the full power of nascent quantum processors requires the efficient management of a limited number of quantum bits with finite lifetime. Hybrid algorithms leveraging classical resources have demonstrated promising initial results…

A local optimization method based on Bayesian Gaussian Processes is developed and applied to atomic structures. The method is applied to a variety of systems including molecules, clusters, bulk materials, and molecules at surfaces. The…

Computational Physics · Physics 2019-09-11 Estefanía Garijo del Río , Jens Jørgen Mortensen , Karsten W. Jacobsen

The work reported in this article presents a high-order, stable, and efficient Gegenbauer pseudospectral method to solve numerically a wide variety of mathematical models. The proposed numerical scheme exploits the stability and the…

Numerical Analysis · Mathematics 2023-03-06 Kareem T. Elgindy

We present a comparison of various approximations to self-consistency in the GW method, including the one-shot G0W0 method, different quasiparticle self-consistency schemes, and the fully self-consistent GW (scGW) approach. To ensure an…

Strongly Correlated Electrons · Physics 2025-10-17 Gaurav Harsha , Vibin Abraham , Ming Wen , Dominika Zgid

We consider three distinct methods to compute the mass spectrum of gauge theories in the Hamiltonian formalism: (1) correlation-function scheme, (2) one-point-function scheme, and (3) dispersion-relation scheme. The first one examines…

High Energy Physics - Lattice · Physics 2023-11-02 Etsuko Itou , Akira Matsumoto , Yuya Tanizaki

Distributed order fractional operators offer a rigorous tool for mathematical modelling of multi-physics phenomena, where the differential orders are distributed over a range of values rather than being just a fixed integer/fraction as it…

Numerical Analysis · Mathematics 2016-05-02 Ehsan Kharazmi , Mohsen Zayernouri , George Em Karniadakis

Iterative multiscale methods for electronic structure calculations offer several advantages for large-scale problems. Here we examine a nonlinear full approximation scheme (FAS) multigrid method for solving fixed potential and…

Materials Science · Physics 2007-05-23 Nimal Wijesekera , Guogang Feng , Thomas L. Beck

Well-conditioned spectral collocation and spectral methods have recently been proposed to solve differential equations. In this paper, we revisit the well-conditioned spectral collocation methods proposed in [T.~A. Driscoll, {\it J. Comput.…

Numerical Analysis · Mathematics 2015-11-05 Kui Du

Classical algorithms for predicting the equilibrium geometry of strongly correlated molecules require expensive wave function methods that become impractical already for few-atom systems. In this work, we introduce a variational quantum…

In this paper a spectral-Lagrangian method for the Boltzmann equation for a multi-energy level gas is proposed. Internal energy levels are treated as separate species and inelastic collisions (leading to internal energy excitation and…

Numerical Analysis · Mathematics 2014-03-05 Alessandro Munafo , Jeffrey R. Haack , Irene M. Gamba , Thierry E. Magin

We propose a method, based on a Generalized Heisenberg Algebra (GHA), to reproduce the anharmonic spectrum of diatomic molecules. The theoretical spectrum generated by GHA allows us to fit the experimental data and to obtain the…

Chemical Physics · Physics 2009-11-11 J. de Souza , N. M. Oliveira-Neto , C. I. Ribeiro-Silva

We propose a marginal likelihood strategy within the Kennedy-O'Hagan (KOH) Bayesian framework, where a Gaussian process (GP) models the discrepancy between a physical system and its simulator. Our approach introduces a novel marginalized…

Quantum Physics · Physics 2025-08-26 Mohammad Motamed , N. Anders Petersson

We present an approach for GW calculations of quasiparticle energies with quasi-quadratic scaling by approximating high-energy contributions to the Green's function in its Lehmann representation with effective stochastic vectors. The method…

Materials Science · Physics 2023-12-07 Aaron R. Altman , Sudipta Kundu , Felipe H. da Jornada