Quenching the Hubbard Model: Comparison of Nonequilibrium Green's Function Methods
Contributions to Plasma Physics, EarlyView.ABSTRACT We benchmark nonequilibrium Green's function (NEGF) approaches for interaction quenches in the half‐filled Fermi–Hubbard model in one and two dimensions. We compare fully self‐consistent two‐time Kadanoff–Baym equations (KBE), the generalized Kadanoff–Baym ansatz (GKBA), and the recently developed NEGF‐based quantum fluctuations approach (NEGF‐
Jan‐Philip Joost +3 more
wiley +1 more source
Variational Partitioned Runge–Kutta Methods for Lagrangians Linear in Velocities
Mathematics, 2019 In this paper, we construct higher-order variational integrators for a class of degenerate systems described by Lagrangians that are linear in velocities.
Tomasz M. Tyranowski, Mathieu Desbrun
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Implicit-Explicit Runge-Kutta schemes for numerical discretization of optimal control problems
, 2012 Implicit-explicit (IMEX) Runge-Kutta methods play a major rule in the numerical treatment of differential systems governed by stiff and non-stiff terms.
Herty, Michael +2 more
core +1 more source
Stability Bounds for the Generalized Kadanoff‐Baym Ansatz in the Holstein Dimer
Contributions to Plasma Physics, EarlyView.ABSTRACT Predicting real‐time dynamics in correlated systems is demanding: exact two‐time Green's function methods are accurate but often too costly, while the Generalized Kadanoff‐Baym Ansatz (GKBA) offers time‐linear propagation at the risk of uncontrolled behavior. We examine when and why GKBA fails in a minimal yet informative setting, the Holstein
Oscar Moreno Segura +2 more
wiley +1 more source
Volterra Runge- Kutta Methods for Solving Nonlinear Volterra Integral Equations
مجلة بغداد للعلوم, 2010 In this paper Volterra Runge-Kutta methods which include: method of order two and four will be applied to general nonlinear Volterra integral equations of the second kind. Moreover we study the convergent of the algorithms of Volterra Runge-Kutta methods.
Baghdad Science Journal
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Optimal Explicit Strong Stability Preserving Runge--Kutta Methods with High Linear Order and optimal Nonlinear Order [PDF]
, 2014 High order spatial discretizations with monotonicity properties are often desirable for the solution of hyperbolic PDEs. These methods can advantageously be coupled with high order strong stability preserving time discretizations.
Gottlieb, Sigal +2 more
core
Coupling Fluid Neutrals to Gyrokinetic Plasma Dynamics for Edge and SOL Turbulence Simulations
Contributions to Plasma Physics, EarlyView.ABSTRACT Accurate modeling of turbulent transport in magnetic confinement fusion devices requires extending first‐principles gyrokinetic simulations from the core to the edge and scrape‐off layer (SOL), where additional physics—particularly plasma–neutrals interactions—must be included.
Sabine Ogier‐Collin +3 more
wiley +1 more source
Efficient Explicit Time Stepping of High Order Discontinuous Galerkin Schemes for Waves
, 2018 This work presents algorithms for the efficient implementation of discontinuous Galerkin methods with explicit time stepping for acoustic wave propagation on unstructured meshes of quadrilaterals or hexahedra.
Kormann, Katharina +3 more
core +1 more source
Local Polynomial Regression and Filtering for a Versatile Mesh‐Free PDE Solver
International Journal for Numerical Methods in Fluids, EarlyView.A high‐order, mesh‐free finite difference method for solving differential equations is presented. Both derivative approximation and scheme stabilisation is carried out by parametric or non‐parametric local polynomial regression, making the resulting numerical method accurate, simple and versatile. Numerous numerical benchmark tests are investigated for
Alberto M. Gambaruto
wiley +1 more source
A Class of Two-Derivative Two-Step Runge-Kutta Methods for Non-Stiff ODEs
Journal of Applied Mathematics, 2019 In this paper, a new class of two-derivative two-step Runge-Kutta (TDTSRK) methods for the numerical solution of non-stiff initial value problems (IVPs) in ordinary differential equation (ODEs) is considered.
I. B. Aiguobasimwin, R. I. Okuonghae
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