English
Related papers

Related papers: Resolving all-order method convergence problems fo…

200 papers

The open-shell reference relativistic equation-of-motion coupled-cluster method within its four-component description is successfully implemented with the consideration of single- and double- excitation approximation. The one-body and…

Atomic Physics · Physics 2016-09-21 Himadri Pathak , Sudip Sasmal , Malaya K. Nayak , Nayana Vaval , Sourav Pal

In this paper, reduced-order models (ROMs) are constructed for the Ablowitz-Ladik equation (ALE), an integrable semi-discretization of the nonlinear Schr\"odinger equation (NLSE) with and without damping. Both ALEs are non-canonical…

Numerical Analysis · Mathematics 2025-06-23 Murat Uzunca , Bülent Karasözen

A practical high-accuracy relativistic method of atomic structure calculations for univalent atoms is presented. The method is rooted in the coupled-cluster formalism and includes non-perturbative treatment of single and double excitations…

Atomic Physics · Physics 2009-11-11 Sergey G. Porsev , Andrei Derevianko

Fourth-order many-body corrections to matrix elements for atoms with one valence electron are derived. The obtained diagrams are classified using coupled-cluster-inspired separation into contributions from n-particle excitations from the…

Atomic Physics · Physics 2009-11-07 Andrei Derevianko , Erik D. Emmons

First-order methods for minimization and saddle point (min-max) problems are widely used for solving large-scale problems, in particular arising in machine learning. The majority of works obtain favorable complexity guarantees of such…

On the way of a microscopic derivation of covariant density functionals, the first complete solution of the relativistic Brueckner-Hartree-Fock (RBHF) equations is presented for symmetric nuclear matter. In most of the earlier…

Nuclear Theory · Physics 2021-09-22 Peter Ring , Sibo Wang , Qiang Zhao , Jie Meng

Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly-bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star…

Nuclear Theory · Physics 2015-06-22 Junchen Pei , George Fann , Robert Harrison , Witold Nazarewicz , Yue Shi , Scott Thornton

Block coordinate descent (BCD) methods approach optimization problems by performing gradient steps along alternating subgroups of coordinates. This is in contrast to full gradient descent, where a gradient step updates all coordinates…

Numerical Analysis · Mathematics 2019-07-29 Simon Rabanser , Lukas Neumann , Markus Haltmeier

A systematic method for calculating higher-order corrections of the relativistic semiclassical fixed-energy amplitude is given. The central scheme in computing corrections of all orders is related to a time ordering operation of an operator…

Quantum Physics · Physics 2007-05-23 De-Hone Lin

Background: The isotropic harmonic oscillator supplemented by a strong spin-orbit interaction has been the cornerstone of nuclear structure since its inception more than seven decades ago. In this paper we introduce---or rather…

Nuclear Theory · Physics 2020-11-11 Junjie Yang , J. Piekarewicz

An algorithm recently presented by Lake to obtain all static spherically symmetric perfect fluid solutions, is extended to the case of locally anisotropic fluids (principal stresses unequal). As expected, the new formalism requires the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Herrera , J. Ospino , A. Di Prisco

We introduce in this document a direct method allowing to solve numerically inverse type problems for linear hyperbolic equations. We first consider the reconstruction of the full solution of the wave equation posed in $\Omega\times (0,T)$…

Optimization and Control · Mathematics 2015-06-11 Nicolae Cindea , Arnaud Munch

We develop a procedure to implement the method of quadric ansatz to a class of second order partial differential equations (PDEs), which includes the four-dimensional K\"ahler-Einstein equation with symmetry and the one-sided type-D…

Exactly Solvable and Integrable Systems · Physics 2023-10-16 Prim Plansangkate

Motivated by the problem of solving the Einstein equations, we discuss high order finite difference discretizations of first order in time, second order in space hyperbolic systems.Particular attention is paid to the case when first order…

General Relativity and Quantum Cosmology · Physics 2010-01-18 M. Chirvasa , S. Husa

In this paper a robust second-order method is developed for the solution of strongly convex l1-regularized problems. The main aim is to make the proposed method as inexpensive as possible, while even difficult problems can be efficiently…

Optimization and Control · Mathematics 2015-01-13 Kimon Fountoulakis , Jacek Gondzio

In this paper we consider new regularization methods for linear inverse problems of dynamic type. These methods are based on dynamic programming techniques for linear quadratic optimal control problems. Two different approaches are…

Numerical Analysis · Mathematics 2021-01-26 S. Kindermann , A. Leitao

In this work, the calculation of complexity on atomic systems is considered. In order to unveil the increasing of this statistical magnitude with the atomic number due to the relativistic effects, recently reported in [A. Borgoo, F. De…

Chaotic Dynamics · Physics 2008-06-12 Jaime Sanudo , Ricardo Lopez-Ruiz

Based on an extension of the Foldy--Wouthuysen method to two-body equations, the problem of expansion of equal-time relativistic equations for two Dirac particles in powers of $1/c$ to higher orders is considered. For the case of two…

Quantum Physics · Physics 2012-11-30 Alexei Turovsky

The dual Dyson series [M.Frasca, Phys. Rev. A {\bf 58}, 3439 (1998)], is used to develop a general perturbative method for the study of atom-field interaction in quantum optics. In fact, both Dyson series and its dual, through…

Quantum Physics · Physics 2009-10-31 Marco Frasca