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Related papers: N-Block Separable Random Phase Approximation: Appl…

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With increasing inter-electronic distance, the screening of the electron-electron interaction by the presence of other electrons becomes the dominant source of electron correlation. This effect is described by the random phase approximation…

Chemical Physics · Physics 2022-09-29 Arno Förster

We present results of the time blocking approximation (TBA) on giant resonances in light, medium and heavy mass nuclei. The TBA is an extension of the widely used random-phase approximation (RPA) adding complex configurations by coupling to…

Nuclear Theory · Physics 2016-09-14 V. Tselyaev , N. Lyutorovich , J. Speth , S. Krewald , P. -G. Reinhard

Large-scale calculations of the E1 strength are performed within the random phase approximation (RPA) based on the relativistic point-coupling mean field approach in order to derive the radiative neutron capture cross sections for all…

Nuclear Theory · Physics 2015-06-11 I. Daoutidis , S. Goriely

Self-Consistent Quasi-Particle RPA (SCQRPA) is for the first time applied to a more level pairing case. Various filling situations and values for the coupling constant are considered. Very encouraging results in comparison with the exact…

Nuclear Theory · Physics 2009-11-07 A. Rabhi , R. Bennaceur , G. Chanfray , P. Schuck

We formulate an adiabatic connection for the exchange-correlation energy in terms of pairing matrix fluctuation. This connection opens new channels for density functional approximations based on pairing interactions. Even the simplest…

Chemical Physics · Physics 2015-06-16 Helen van Aggelen , Yang Yang , Weitao Yang

A new Quasiparticle Random Phase Approximation approach is presented. The corresponding ground state is variationally determined and exhibits a minimum energy. New solutions for the ground state, some with spontaneously broken symmetry, of…

Nuclear Theory · Physics 2008-11-26 F. Simkovic , M. Smotlak , A. A. Raduta

We present an extension of the random--phase approximation (RPA) where the RPA phonons are used as building blocks to construct the excited states. In our model, that we call double RPA (DRPA), we include up to two RPA phonons. This is an…

Nuclear Theory · Physics 2016-02-17 D. Gambacurta , F. Catara , M. Grasso , M. Sambataro , M. V. Andrés , E. G. Lanza

A general but simple method is proposed to eliminate the quantum fluctuations generated by selected one-body operators in the excitation spectrum of a discrete RPA Hamiltonian. This method provides an outstanding tool for the removal of the…

Nuclear Theory · Physics 2009-11-10 F. Dönau

We show that the entropy of entanglement is sensitive to the coherent quantum phase transition between normal and super-radiant regions of a system of a finite number of three-level atoms interacting in a dipolar approximation with a…

Quantum Physics · Physics 2019-08-20 Luis Fernando Quezada , Eduardo Nahmad-Achar

The one-dimensional contact process is analyzed by a cluster approximation. In this approach, the hierarchy of rate equations for the densities of finite length empty intervals are truncated under the assumption that adjacent intervals are…

Condensed Matter · Physics 2009-10-22 E. Ben-Naim , P. L. Krapivsky

We study a distributed Principal Component Analysis (PCA) framework where each worker targets a distinct eigenvector and refines its solution by updating from intermediate solutions provided by peers deemed as "superior". Drawing intuition…

Machine Learning · Computer Science 2025-02-27 Fangshuo Liao , Wenyi Su , Anastasios Kyrillidis

In high-energy heavy-ion collisions, structures in the initial collision zone are a matter of intense investigation, both from theory and experimental points of view. A large number of models have been developed to represent the initial…

Nuclear Theory · Physics 2021-04-02 Shreyasi Acharya , Subhasis Chattopadhyay

Self Consistent Quasiparticle Random Phase Approximation (SCQRPA) is considered in application to the Fermi transitions within the O(5) model. It is demonstrated that SCQRPA improves on renormalized QRPA (RQRPA), a method that has recently…

Nuclear Theory · Physics 2009-10-31 F. Krmpotic , E. J. V. de Passos , D. S. Delion , J. Dukelsky , P. Schuck

The relativistic random phase approximation is applied in the analysis of the evolution of the isovector dipole response in nuclei with a large neutron excess. The self-consistent framework of relativistic mean-field theory, which has been…

Nuclear Theory · Physics 2009-11-07 D. Vretenar , N. Paar , P. Ring , G. A. Lalazissis

In the derivation of low-energy effective models for solids targeting the bands near the Fermi level, the constrained random phase approximation (cRPA) has become an appreciated tool to compute the effective interactions. The Wick-ordered…

Strongly Correlated Electrons · Physics 2015-07-15 Michael Kinza , Carsten Honerkamp

First-principles dynamical CPA (Coherent-Potential Approximation) for electron correlations has been developed further by taking into account higher-order dynamical corrections with use of the asymptotic approximation. The theory is applied…

Strongly Correlated Electrons · Physics 2015-05-19 Y. Kakehashi , M. Atiqur R. Patoary , T. Tamashiro

We discuss that in the random phase approximation (RPA) the first derivative of the energy with respect to the Green's function is the self-energy in the GW approximation. This relationship allows us to derive compact equations for the RPA…

Chemical Physics · Physics 2017-03-22 Benjamin Ramberger , Tobias Schäfer , Georg Kresse

We examine to which extent correlated realistic nucleon-nucleon interactions, derived within the Unitary Correlation Operator Method (UCOM), can describe nuclear collective motion in the framework of first-order random-phase approximation…

Nuclear Theory · Physics 2008-11-26 P. Papakonstantinou , R. Roth , N. Paar

Starting from the general expression for the ground state correlation energy in the adiabatic connection fluctuation dissipation theorem (ACFDT) framework, it is shown that the dielectric matrix formulation, which is usually applied to…

Chemical Physics · Physics 2016-04-25 Bastien Mussard , Dario Rocca , Georg Jansen , Janos Angyan

The covariant particle-vibration coupling model within the time blocking approximation is employed to supplement the Relativistic Random Phase Approximation (RRPA) with coupling to collective vibrations. The Bethe-Salpeter equation in the…

Nuclear Theory · Physics 2008-11-26 E. Litvinova , P. Ring , V. Tselyaev
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