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The acoustic scattering problem is modeled by the exterior Helmholtz equation, which is challenging to solve due to both the unboundedness of the domain and the high dispersion error, known as the pollution effect. We develop high-order…

Numerical Analysis · Mathematics 2026-04-14 Bin Han , Jiwoon Sim

Emerging sampling algorithms based on normalizing flows have the potential to solve ergodicity problems in lattice calculations. Furthermore, it has been noted that flows can be used to compute thermodynamic quantities which are difficult…

High Energy Physics - Lattice · Physics 2023-10-02 Jan M. Pawlowski , Julian M. Urban

The field mixing that manifests broken particle-hole symmetry is studied for a 2-D asymmetric lattice gas model having tunable field mixing properties. Monte Carlo simulations within the grand canonical ensemble are used to obtain the…

Condensed Matter · Physics 2009-10-22 N. B. Wilding

We study the one-point and two-point Green's functions in a complex random matrix model to sub-leading orders in the large N limit. We take this complex matrix models as a model for the two-state scattering problem, as applied to spin…

Condensed Matter · Physics 2009-10-28 S. Hikami , A. Zee

Using a coarse molecular-dynamics (CMD) approach with an appropriate choice of coarse variable (order parameter), we map the underlying effective free-energy landscape for the melting of a crystalline solid. Implementation of this approach…

Materials Science · Physics 2009-11-11 Miguel A. Amat , Ioannis G. Kevrekidis , Dimitrios Maroudas

In this paper, we develop a method for estimating and clustering two-dimensional spectral density functions (2D-SDFs) for spatial data from multiple subregions. We use a common set of adaptive basis functions to explain the similarities…

Methodology · Statistics 2020-07-29 Tianbo Chen , Ying Sun , Mehdi Maadooliat

Estimating the density of states of systems with rugged free energy landscapes is a notoriously difficult task of the utmost importance in many areas of physics ranging from spin glasses to biopolymers. Density of states estimation has also…

Statistical Mechanics · Physics 2019-07-31 Lev Barash , Jeffrey Marshall , Martin Weigel , Itay Hen

We describe an efficient Monte Carlo algorithm using a random walk in energy space to obtain a very accurate estimate of the density of states for classical statistical models. The density of states is modified at each step when the energy…

Statistical Mechanics · Physics 2009-11-07 Fugao Wang , David. P. Landau

We present linear response theories in the continuum capable of describing continuum spectra and dynamical correlations of finite systems with no spatial symmetry. Our formulation is essentially the same as the continuum random-phase…

Nuclear Theory · Physics 2007-05-23 Takashi Nakatsukasa , Kazuhiro Yabana

The local density of states (LDOS) in finite quantum wires is calculated as a function of discrete energies and position along the wire. By using a combination of numerical density matrix renormalization group (DMRG) calculations and…

Strongly Correlated Electrons · Physics 2009-11-13 Imke Schneider , Alexander Struck , Michael Bortz , Sebastian Eggert

A semiclassical theory of single and multi-mode lasing is derived for open complex or random media using a self-consistent linear response formulation. Unlike standard approaches which use closed cavity solutions to describe the lasing…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Hakan E. Tureci , A. Douglas Stone , B. Collier

The phase diagram of QCD at finite temperature and density and the existence of a critical point are currently very actively researched topics. Although tremendous progress has been made, in the case of two light quark flavors even the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Bertram Klein , Jens Braun

We present an efficient implementation of a surface Green's-function method for atomistic modeling of surfaces within the framework of density functional theory using a pseudopotential localized basis set approach. In this method, the…

Cluster analysis, or clustering, plays a crucial role across numerous scientific and engineering domains. Despite the wealth of clustering methods proposed over the past decades, each method is typically designed for specific scenarios and…

Methodology · Statistics 2026-01-22 Siyi Wang , Alexandre Leblanc , Paul D. McNicholas

We present an implementation of equation of motion coupled-cluster singles and doubles (EOM-CCSD) theory using periodic boundary conditions and a plane wave basis set. Our implementation of EOM-CCSD theory is applied to study $F$-centers in…

Materials Science · Physics 2021-02-09 Alejandro Gallo , Felix Hummel , Andreas Irmler , Andreas Grüneis

We present a high order perturbation approach to quantitatively calculate spectral densities in three distinct steps starting from the model Hamiltonian and the observables of interest. The approach is based on the perturbative continuous…

Strongly Correlated Electrons · Physics 2009-11-10 Christian Knetter , Kai P. Schmidt , Götz S. Uhrig

We derive a density matrix (DM) theory for quantum cascade lasers (QCLs) that describes the influence of scattering on coherences through a generalized scattering superoperator. The theory enables quantitative modeling of QCLs, including…

Mesoscale and Nanoscale Physics · Physics 2017-08-28 Andrew Pan , Benjamin A. Burnett , Chi On Chui , Benjamin S. Williams

We study the QCD phase diagram by first principle lattice calculations at so far unreached high densities. For this purpose we employ the density of states method. Unimproved staggered fermions, which describe four quark flavors in the…

High Energy Physics - Lattice · Physics 2010-10-27 Zoltan Fodor , Sandor D. Katz , Christian Schmidt

Using Wang-landau algorithm combined with analytic method, the density of states of two dimensional XY model on square lattices of sizes $16\times16$, $24\times24$ and $32\times32$ is accurately calculated. Thermodynamic quantities, such as…

Statistical Mechanics · Physics 2010-03-16 Jun Xu , H. R. Ma

A rigorous method of calculating the electromagnetic field, the scattering matrix, and scattering cross-sections of an arbitrary finite three-dimensional optical system described by its permittivity distribution is presented. The method is…

Optics · Physics 2018-09-26 S. V. Lobanov , W. Langbein , E. A. Muljarov