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A recently developed variant of the so-called optimized perturbation theory (OPT), making it perturbatively consistent with renormalization group (RG) properties, RGOPT, was shown to drastically improve its convergence for zero temperature…

High Energy Physics - Phenomenology · Physics 2015-12-30 J. -L. Kneur , M. B. Pinto

We propose a practicable method for describing linear dynamics of different finite Fermi systems. The method is based on a general self-consistent procedure for factorization of the two-body residual interaction. It is relevant for diverse…

Atomic and Molecular Clusters · Physics 2011-05-26 V. O. Nesterenko , J. Kvasil , P. -G. Reinhard

A limitation common to all extensions of random-phase approximation including only particle-hole configurations is that they violate to some extent the energy weighted sum rules. Considering one such extension, the improved RPA (IRPA),…

Nuclear Theory · Physics 2009-11-07 M. Grasso , F. Catara

A variational principle is further developed for out of equilibrium dynamical systems by using the concept of maximum entropy. With this new formulation it is obtained a set of two first-order differential equations, revealing the same…

Data Analysis, Statistics and Probability · Physics 2019-03-22 Mario J. Pinheiro

We study the optimisation of exact renormalisation group (ERG) flows. We explain why the convergence of approximate solutions towards the physical theory is optimised by appropriate choices of the regularisation. We consider specific…

High Energy Physics - Theory · Physics 2009-11-07 Daniel F. Litim

A thermodynamically self-consistent Ornstein-Zernike approximation (SCOZA) is applied to a fluid of spherical particles with a pair potential given by a hard-core repulsion and a Yukawa attractive tail $w(r)=-\exp [-z(r-1)]/r$. This…

Statistical Mechanics · Physics 2009-10-31 D. Pini , G. Stell , N. B. Wilding

We review the inherent structure thermodynamical formalism and the formulation of an equation of state for liquids in equilibrium based on the (volume) derivatives of the statistical properties of the potential energy surface. We also show…

Soft Condensed Matter · Physics 2009-11-07 S. Mossa , E. La Nave , P. Tartaglia , F. Sciortino

Approximation algorithms for classical constraint satisfaction problems are one of the main research areas in theoretical computer science. Here we define a natural approximation version of the QMA-complete local Hamiltonian problem and…

Quantum Physics · Physics 2016-10-25 Sevag Gharibian , Julia Kempe

We calculate local potential energy minima (inherent structures) for a simple model of orthoterphenyl (OTP), from computer simulations over a wide temperature range. We show that the results are very sensitive to the system size. We locate,…

Soft Condensed Matter · Physics 2009-09-25 Francesco Sciortino , Srikanth Sastry , Piero Tartaglia

A recently introduced general-purpose heuristic for finding high-quality solutions for many hard optimization problems is reviewed. The method is inspired by recent progress in understanding far-from-equilibrium phenomena in terms of {\em…

Neural and Evolutionary Computing · Computer Science 2007-05-23 Stefan Boettcher , Allon G. Percus

We consider several spin-unrestricted random-phase approximation (RPA) variants for calculating correlation energies, with and without range separation, and test them on datasets of atomization energies and reaction barrier heights. We show…

Chemical Physics · Physics 2016-03-01 Bastien Mussard , Peter Reinhardt , Janos Angyan , Julien Toulouse

A self-consistent random phase approximation (RPA) is proposed as an effective Hamiltonian method in Light-Front Field Theory (LFFT). We apply the general idea to the light-front massive Schwinger model to obtain a new bound state equation…

High Energy Physics - Theory · Physics 2009-10-31 Koji Harada

Approximate algorithms for structured prediction problems---such as LP relaxations and the popular alpha-expansion algorithm (Boykov et al. 2001)---typically far exceed their theoretical performance guarantees on real-world instances. These…

Machine Learning · Statistics 2018-04-24 Hunter Lang , David Sontag , Aravindan Vijayaraghavan

We assess the performance of a recently proposed renormalized adiabatic local density approximation (rALDA) for \textit{ab initio} calculations of electronic correlation energies in solids and molecules. The method is an extension of the…

Materials Science · Physics 2014-05-30 Thomas Olsen , Kristian S. Thygesen

The mean spherical approximation (MSA) can be solved semi-analytically for the Gaussian core model (GCM) and yields - rather surprisingly - exactly the same expressions for the energy and the virial equations. Taking advantage of this…

Soft Condensed Matter · Physics 2016-08-31 Bianca M. Mladek , Gerhard Kahl , Martin Neumann

Self-consistent random phase approximation (SCRPA) is applied to the exactly solvable model with fermion boson coupling proposed by Sch\"utte and Da-Providencia. Very encouraging results in comparison with the exact solution of the model…

Nuclear Theory · Physics 2009-11-10 A. Rabhi

Progresses in additive manufacturing technologies allow the realization of finely graded microstructured materials with tunable mechanical properties. This paves the way to a wealth of innovative applications, calling for the combined…

Analysis of PDEs · Mathematics 2023-07-10 Stefano Almi , Ulisse Stefanelli

We consider finite element approximations of ill-posed elliptic problems with conditional stability. The notion of {\emph{optimal error estimates}} is defined including both convergence with respect to mesh parameter and perturbations in…

Numerical Analysis · Mathematics 2024-03-25 Erik Burman , Mihai Nechita , Lauri Oksanen

The random phase approximation (RPA) as formulated as an orbital-dependent, fifth-rung functional within the density functional theory (DFT) framework offers a promising approach for calculating the ground-state energies and the derived…

Computational Physics · Physics 2023-07-25 Rong Shi , Peize Lin , Min-Ye Zhang , Lixin He , Xinguo Ren

This study uses continuum thermodynamics of pure thermoelastic fluids to examine their phase transformation. To examine phase transformation kinetics, a special emphasis is placed on the jump condition for the axiom of entropy inequality,…

Statistical Mechanics · Physics 2022-07-29 Gerard A. Ateshian , Jay J. Shim