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Related papers: Minimal pole representation for spectral functions

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We develop Green's function formalism to describe continuous multi-layered quasi-one-dimensional setups described by piece-wise constant single-particle Hamiltonians. The Hamiltonians of the individual layers are assumed to be quadratic…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 Kiryl Piasotski , Mikhail Pletyukhov , Alexander Shnirman

The real-time contour formalism for Green's functions provides time-dependent information of quantum many-body systems. In practice, the long-time simulation of systems with a wide range of energy scales is challenging due to both the…

Strongly Correlated Electrons · Physics 2022-10-04 Xinyang Dong , Emanuel Gull , Hugo U. R. Strand

The normalized spectral representation of a max-stable process on a compact set is the unique representation where all spectral functions share the same supremum. Among the class of equivalent spectral representations of a process, the…

Probability · Mathematics 2013-10-08 Marco Oesting , Martin Schlather , Chen Zhou

In this paper we study the question of effective field assignment to measured or nonperturbatively calculated spectral functions. The straightforward procedure is to approximate it by a sum of independent Breit-Wigner resonances, and assign…

High Energy Physics - Phenomenology · Physics 2015-06-05 A. Jakovac

We present a calculation of the spectral properties of a single charge doped at a Cu($3d$) site of the Cu-F plane in KCuF$_{3}$. The problem is treated by generating the equations of motion for the Green's function by means of subsequent…

Strongly Correlated Electrons · Physics 2016-12-26 Krzysztof Bieniasz , Mona Berciu , Andrzej M. Oleś

Analytical continuation is a central step in the simulation of finite-temperature field theories in which numerically obtained Matsubara data is continued to the real frequency axis for physical interpretation. Numerical analytic…

Strongly Correlated Electrons · Physics 2024-10-21 Lei Zhang , Emanuel Gull

According to recent Quantum Monte Carlo simulations the small polaron theory is practically exact in a wide range of the long-range (Frohlich) electron-phonon coupling and adiabatic ratio. We apply the Lang-Firsov transformation to convert…

Superconductivity · Physics 2009-10-31 A. S. Alexandrov , C. Sricheewin

A classical problem in acoustic (and electromagnetic) scattering concerns the evaluation of the Green's function for the Helmholtz equation subject to impedance boundary conditions on a half-space. The two principal approaches used for…

Numerical Analysis · Mathematics 2012-11-28 Michael O'Neil , Leslie Greengard , Andras Pataki

By introducing multipe-site correlation functions, we propose a hierarchical Green function approach, and apply it to study the characteristic properties of a 2D square lattice Hubbard model by solving the equation of motions of a…

Strongly Correlated Electrons · Physics 2018-09-26 Yu-Liang Liu

Efficient ab initio calculations of correlated materials at finite temperature require compact representations of the Green's functions both in imaginary time and Matsubara frequency. In this paper, we introduce a general procedure which…

Strongly Correlated Electrons · Physics 2020-04-01 Jia Li , Markus Wallerberger , Naoya Chikano , Chia-Nan Yeh , Emanuel Gull , Hiroshi Shinaoka

We introduce a quantum dot orbital tight-binding non-equilibrium Green's function approach for the simulation of novel solar cell devices where both absorption and conduction are mediated by quantum dot states. By the use of basis states…

Mesoscale and Nanoscale Physics · Physics 2012-06-14 U. Aeberhard

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

In this work we present a three step procedure for generating a closed form expression of the Green's function on both closed and open finite quantum graphs with general self-adjoint matching conditions. We first generalize and simplify the…

Quantum Physics · Physics 2023-09-21 Tristan Lawrie , Sven Gnutzmann , Gregor Tanner

We introduce a spectral density functional theory which can be used to compute energetics and spectra of real strongly--correlated materials using methods, algorithms and computer programs of the electronic structure theory of solids. The…

Strongly Correlated Electrons · Physics 2009-11-10 S. Y. Savrasov , G. Kotliar

We report on the derivation of determinant representations for the Green's functions and spectral function of the trapped Tonks-Girardeau gas on the lattice and in the continuum. Our results are valid for any type of statistics of the…

Quantum Gases · Physics 2023-04-12 Ovidiu I. Patu

The spectral function for finite nuclei is computed within the framework of the Local Density Approximation, starting from nuclear matter spectral functions obtained with a realistic nucleon-nucleon interaction. The spectral function is…

Nuclear Theory · Physics 2008-11-26 D. Van Neck , A. E. L. Dieperink , E. Moya de Guerra

The quality of numerically simulated spectra using real-time evolution methods for strongly correlated systems is affected by both the length of simulation time and the system size, limiting resolution in both frequency and momentum. In…

Strongly Correlated Electrons · Physics 2025-09-22 Ta Tang , Chunjing Jia , Brian Moritz , Thomas P. Devereaux

The spectral representation separates the contributions of geometrical arrangement (topology) and intrinsic constituent properties in a composite. The aim of paper is to present a numerical algorithm based on the Monte Carlo integration and…

Other Condensed Matter · Physics 2007-05-23 Enis Tuncer

In the context of functional data analysis, probability density functions as non-negative functions are characterized by specific properties of scale invariance and relative scale which enable to represent them with the unit integral…

Numerical Analysis · Mathematics 2019-12-19 Jitka Machalova , Renata Talska , Karel Hron , Ales Gaba

This paper considers the approximation of spatial convolution with a given radial integral kernel. Previous studies have demonstrated that approximating spatial convolution using a system of partial differential equations (PDEs) can…

Analysis of PDEs · Mathematics 2025-04-15 Hiroshi Ishii , Yoshitaro Tanaka