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Related papers: RPA calculations with Gaussian expansion method

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A new implementation of the GW approximation (GWA) based on the all-electron Projector-Augmented-Wave method (PAW) is presented, where the screened Coulomb interaction is computed within the Random Phase Approximation (RPA) instead of the…

Materials Science · Physics 2009-11-10 S. Lebègue , B. Arnaud , M. Alouani , P. E. Bloechl

Bayesian inference is a popular method to build learning algorithms but it is hampered by the fact that its key object, the posterior probability distribution, is often uncomputable. Expectation Propagation (EP) (Minka (2001)) is a popular…

Machine Learning · Statistics 2016-12-16 Guillaume P. Dehaene

Bayesian graphical models are a useful tool for understanding dependence relationships among many variables, particularly in situations with external prior information. In high-dimensional settings, the space of possible graphs becomes…

Machine Learning · Statistics 2019-02-07 Zehang Richard Li , Tyler H. McCormick

Double excitations are crucial to understanding numerous chemical, physical, and biological processes, but accurately predicting them remains a challenge. In this work, we explore the particle-particle random phase approximation (ppRPA) as…

Chemical Physics · Physics 2024-11-26 Jincheng Yu , Jiachen Li , Tianyu Zhu , Weitao Yang

We calculate the energy-dependent cross section of the $np\leftrightarrow d\gamma$ process in chiral effective field theory and apply state-of-the-art tools for quantification of theory uncertainty. We focus on the low-energy regime, where…

Nuclear Theory · Physics 2022-03-24 Bijaya Acharya , Sonia Bacca

By measuring angular-oscillation behavior of the heat capacity with respect to the applied field direction, one can detect the details of the gap structure. We introduce the Kramer-Pesch approximation (KPA) as a new method to analyze the…

Superconductivity · Physics 2008-08-29 Yuki Nagai , Nobuhiko Hayashi

A new approach for creating a non-ergodic $PSA$ ground-motion model (GMM) is presented which account for the magnitude dependence of the non-ergodic effects. In this approach, the average $PSA$ scaling is controlled by an ergodic $PSA$ GMM,…

Applications · Statistics 2021-07-21 Grigorios Lavrentiadis , Norman A. Abrahamson

This paper describes an expectation propagation (EP) method for multi-class classification with Gaussian processes that scales well to very large datasets. In such a method the estimate of the log-marginal-likelihood involves a sum across…

Machine Learning · Statistics 2017-06-23 Carlos Villacampa-Calvo , Daniel Hernández-Lobato

We present an efficient numerical technique to evaluate the matrix of the (quasiparticle)-random-phase approximation, using the finite amplitude method (FAM). The method is tested in calculation of monopole excitations in 120Sn, compared…

Nuclear Theory · Physics 2013-02-11 Paolo Avogadro , Takashi Nakatsukasa

We present an analytic proof demonstrating the equivalence between the Random Phase Approximation (RPA) to the ground state correlation energy and a ring-diagram simplification of the Coupled Cluster Doubles (CCD) equations. In the CCD…

Other Condensed Matter · Physics 2009-11-13 Gustavo E. Scuseria , Thomas M. Henderson , Danny C. Sorensen

A method to reconstruct fields, source strengths and physical parameters based on Gaussian process regression is presented for the case where data are known to fulfill a given linear differential equation with localized sources. The…

Data Analysis, Statistics and Probability · Physics 2019-09-10 Christopher G. Albert

A method of the self-consistent calculation of the thermodynamical and correlation functions is presented. This approach is based on the GRPA (generalized random phase approximation) scheme with the inclusion of the mean field corrections.…

Superconductivity · Physics 2016-08-31 I. V. Stasyuk , A. M. Shvaika , K. V. Tabunshchyk

Working within an exactly solvable 3 level model, we discuss am extension of the Random Phase Approximation (RPA) based on a boson formalism. A boson Hamiltonian is defined via a mapping procedure and its expansion truncated at four-boson…

Nuclear Theory · Physics 2016-09-08 F. Catara , M. Grasso , M. Sambataro

Dependent generalized extreme value (dGEV) models have attracted much attention due to the dependency structure that often appears in real datasets. To construct a dGEV model, a natural approach is to assume that some parameters in the…

Methodology · Statistics 2017-03-06 Bo Ning , Peter Bloomfield

Valuable theoretical predictions of nuclear dipole excitations in the whole chart are of great interest for different nuclear applications, including in particular nuclear astrophysics. Here we present large-scale calculations of the $E1$…

Nuclear Theory · Physics 2016-07-29 M. Martini , S. Péru , S. Hilaire , S. Goriely , F. Lechaftois

We present a quantum algorithm for efficiently sampling transformed Gaussian random fields on $d$-dimensional domains, based on an enhanced version of the classical moving average method. Pointwise transformations enforcing boundedness are…

Quantum Physics · Physics 2025-08-20 Matthias Deiml , Daniel Peterseim

We perform a self-consistent relativistic RPA calculation for the isobaric analogue and Gamow-Teller resonances based on relativistic mean field theory results for the ground states of $^{48}$Ca, $^{90}$Zr and $^{208}$Pb. We use the…

Nuclear Theory · Physics 2009-10-31 C. De Conti , A. P. Galeao , F. Krmpotic

The properties of metallic systems with important and structured excitations at low energies, such as Cu, are challenging to describe with simple models like the plasmon pole approximation (PPA), and more accurate and sometimes prohibitive…

Materials Science · Physics 2023-04-26 Dario A. Leon , Andrea Ferretti , Daniele Varsano , Elisa Molinari , Claudia Cardoso

We use a solvable model to perform modified dyson mapping and reveal the unphysical-state effects in the original Random Phase Approximation (RPA). We then propose a method to introduce the RPA and improve it based on a Boson mapping.

Nuclear Theory · Physics 2007-05-23 Shi-Lin Zhu , Zhi-ning Zhou , Ze-sen Yang

We determine the correlation energy of BN, SiO$_2$ and ice polymorphs employing a recently developed RPAx (random phase approximation with exchange) approach. The RPAx provides larger and more accurate polarizabilities as compared to the…

Materials Science · Physics 2021-09-22 Maria Hellgren , Lucas Baguet