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The Jost function method is extended within the framework of the RPA theory to find poles on the complex energy plane that exhibit complex RPA eigenenergies. Poles corresponding to the RPA excited states such as the giant resonance of…

Nuclear Theory · Physics 2022-12-06 K. Mizuyama , N. Nhu Le , T. V. Nhan Hao , N. Hoang Tung , T. Dieu Thuy

By using the Continuum RPA (CRPA) method, the incoherent transition strength of the exotic mu - e conversion in the 208Pb and 40Ca nuclei is investigated. The question whether excited nuclear states lying high in the continuum give an…

Nuclear Theory · Physics 2007-05-23 P. Papakonstantinou , O. Civitarese , T. S. Kosmas , J. Wambach

The low-lying dipole and quadrupole states in neutron rich nuclei, are studied within the fully self-consistent relativistic quasiparticle random-phase approximation (RQRPA), formulated in the canonical basis of the Relativistic…

Nuclear Theory · Physics 2009-11-10 N. Paar , T. Niksic , D. Vretenar , P. Ring

We investigate the use of an operatorial basis in a self-consistent theory of large amplitude collective motion. For the example of the pairing-plus-quadrupole model, which has been studied previously at equilibrium, we show that a small…

Nuclear Theory · Physics 2009-11-10 Daniel Almehed , Niels R. Walet

We propose an efficient analytical representation of the frequency-dependent $GW$ self-energy $\Sigma$ via a multipole approximation (MPA-$\Sigma$). The multipole-Pad\'e model for the self-energy is interpolated from a small set of…

Materials Science · Physics 2025-05-16 Dario A. Leon , Kristian Berland , Claudia Cardoso

Probe-level models have led to improved performance in microarray studies but the various sources of probe-level contamination are still poorly understood. Data-driven analysis of probe performance can be used to quantify the uncertainty in…

Computational Engineering, Finance, and Science · Computer Science 2013-04-09 Leo Lahti , Laura L. Elo , Tero Aittokallio , Samuel Kaski

Isoscalar dipole (compression) mode is studied first using schematic harmonic-oscillator model and, then, the self-consistent Hartree-Fock (HF) and random phase approximation (RPA) solved in coordinate space. Taking ^{208}Pb and the SkM*…

Nuclear Theory · Physics 2009-11-07 I. Hamamoto , H. Sagawa

This paper describes a method to do ab initio molecular dynamics in electronically excited systems within the random phase approximation (RPA). Using a dynamical variational treatment of the RPA frequency, which corresponds to the…

Condensed Matter · Physics 2009-10-31 Eric R. Bittner , D. S. Kosov

For the first time a fully self-consistent charge-exchange relativistic RPA based on the relativistic Hartree-Fock (RHF) approach is established. The self-consistency is verified by the so-called isobaric analog state (IAS) check. The…

Nuclear Theory · Physics 2008-11-26 Haozhao Liang , Nguyen Van Giai , Jie Meng

We construct and analyze a rate-based neural network model in which self-interacting units represent clusters of neurons with strong local connectivity and random inter-unit connections reflect long-range interactions. When sufficiently…

Disordered Systems and Neural Networks · Physics 2015-06-22 Merav Stern , Haim Sompolinsky , L. F. Abbott

The isoscalar and isovector collective multipole excitations in stable nuclei are studied in the framework of relativistic random-phase approximation with the vacuum polarization arising from the nucleon-antinucleon field. A fully…

Nuclear Theory · Physics 2007-05-23 A. Haga , H. Toki , S. Tamenaga , Y. Horikawa

We investigate the reliability of transition strengths computed in the random-phase approximation (RPA), comparing with exact results from diagonalization in full $0\hbar\omega$ shell-model spaces. The RPA and shell-model results are in…

Nuclear Theory · Physics 2009-11-07 Ionel Stetcu , Calvin W. Johnson

The coherent potential approximation (CPA) is extended to describe satisfactorily the motion of particles in a random potential which is spatially correlated and smoothly varying. In contrast to existing cluster-CPA methods, the present…

Disordered Systems and Neural Networks · Physics 2009-10-20 Roland Zimmermann , Christoph Schindler

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

The tight-coupling approximation (TCA) used to describe the early dynamics of the baryons-photons system is systematically built to higher orders in the inverse of the interaction rate. This expansion can be either used to grasp the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Cyril Pitrou

We have used the Hartree-Fock Random Phase Approximation (HF-RPA) to study the interacting electron gas in a quantum wire. The spectra of intersubband spin-flip excitations reveal a considerable red shift with respect to single-particle HF…

Condensed Matter · Physics 2009-10-28 Arne Brataas , A. G. Mal'shukov , Vidar Gudmundsson , K. A. Chao

Roles of antinucleon degrees of freedom in the relativistic random phase approximation(RPA) are investigated. The energy-weighted sum of the RPA transition strengths is expressed in terms of the double commutator between the excitation…

Nuclear Theory · Physics 2015-12-14 Haruki Kurasawa , Toshio Suzuki

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

The consistency condition is tested within the particle-particle random-phase approximation (RPA), renormalized RPA (RRPA) and the self-consistent RPA (SCRPA) making use of the Richardson model of pairing. The two-particle separation energy…

Nuclear Theory · Physics 2009-11-11 Nguyen Dinh Dang

Several approaches to photonuclear reactions, based on the time-dependent density-functional theory, have been developed recently. The standard linearization leads to the random-phase approximation (RPA) or the quasiparticle-random-phase…