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Related papers: Kadanoff-Baym Equations with Initial Correlations

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A recently developed method for incorporating initial binary correlations into the Kadanoff-Baym equations (KBE) is used to derive a generalized T-matrix approximation for the self-energies. It is shown that the T-matrix obtains additional…

Statistical Mechanics · Physics 2015-06-25 D. Semkat , D. Kremp , M. Bonitz

The generalized Kadanoff-Baym ansatz (GKBA) offers a computationally inexpensive approach to simulate out-of-equilibrium quantum systems within the framework of nonequilibrium Green's functions. For finite systems the limitation of…

Mesoscale and Nanoscale Physics · Physics 2021-03-02 Riku Tuovinen , Robert van Leeuwen , Enrico Perfetto , Gianluca Stefanucci

The Keldysh boundary problem in a nonequilibrium Falicov-Kimball model in infinite dimensions is studied within the truncated and self-consistent perturbation theories, and the dynamical mean-field theory. Within the model the system is…

Strongly Correlated Electrons · Physics 2009-11-13 Minh-Tien Tran

In a recent Rapid Communication [A. Stan, Phys. Rev. B \textbf{93}, 041103(R) (2016)], the reliability of the Keldysh--Kadanoff--Baym equations (KBE) using correlated selfenergy approximations applied to linear and nonlinear response has…

Strongly Correlated Electrons · Physics 2017-09-27 N. Schlünzen , J. -P. Joost , M. Bonitz

We study time-dependent quantum transport in a correlated model system by means of time-propagation of the Kadanoff-Baym equations for the nonequilibrium many-body Green function. We consider an initially contacted equilibrium system of a…

Mesoscale and Nanoscale Physics · Physics 2011-11-28 Petri Myöhänen , Adrian Stan , Gianluca Stefanucci , Robert van Leeuwen

The nonequilibrium dynamics of quantum fields is an initial-value problem, which can be described by Kadanoff-Baym equations. Typically, and in particular when numerical solutions are demanded, these Kadanoff-Baym equations are restricted…

High Energy Physics - Phenomenology · Physics 2009-12-01 Mathias Garny , Markus Michael Muller

The short-time dynamics of correlated systems is strongly influenced by initial correlations giving rise to an additional collision integral in the non-Markovian kinetic equation. Exact cancellation of the two integrals is found if the…

Plasma Physics · Physics 2016-08-15 K. Morawetz , M. Bonitz , V. G. Morozov , G. Röpke , D. Kremp

We present in detail a method we recently introduced (PRL. 103, 176404 (2009)) to describe finite systems in and out of equilibrium, where the evolution in time is performed via the Kadanoff-Baym Equations (KBE) within Many-Body…

Strongly Correlated Electrons · Physics 2010-04-22 M. Puig von Friesen , C. Verdozzi , C. -O. Almbladh

Using the Kadanoff-Baym non-equilibrium Green's function formalism, we derive kinetic equations for the non-condensate atoms at finite temperatures which include the effect of binary collisions between atoms. The effect of collisions is…

Condensed Matter · Physics 2017-08-23 Milena Imamovic-Tomasovic , Allan Griffin

The generalized Kadanoff-Baym ansatz (GKBA) is an approximation to the Kadanoff-Baym equations (KBE), that neglects certain memory effects that contribute to the Green's function at non-equal times. Here we present arguments and numerical…

Computational Physics · Physics 2023-09-06 Cian C. Reeves , Yuanran Zhu , Chao Yang , Vojtech Vlcek

We reconsider the Generalized Kadanoff--Baym Ansatz (GKBA) approximation for non-equilibrium Green's functions and extend it to self-consistently define an equilibrium correlated (within GKBA) state in closed systems. The advantage of the…

Mesoscale and Nanoscale Physics · Physics 2019-02-20 Miroslav Hopjan , Claudio Verdozzi

The Kadanoff-Baym (KB) equations are solved numerically for infinite nuclear matter. In particular we calculate correlation energies and correlation times. Approximating the Green's functions in the KB collision kernel by the free Green's…

Nuclear Theory · Physics 2009-11-07 H. S. Köhler , K. Morawetz

Real-time Green's function simulations of molecular junctions (open quantum systems) are typically performed by solving the Kadanoff-Baym equations (KBE). The KBE, however, impose a serious limitation on the maximum propagation time due to…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 S. Latini , E. Perfetto , A. -M. Uimonen , R. van Leeuwen , G. Stefanucci

In the context of a broad class of quenched models, we derive a generalized differential form of the Kadanoff-Baym (KB) ansatz which relates the out of equilibrium correlated and spectral Green's functions. This relation holds at any time…

High Energy Physics - Theory · Physics 2016-05-25 A. L. M. Britto , Ashok K. Das , J. Frenkel

We use the 2 particle irreducible Schwinger-Keldysh effective action to set up consistent equations for the velocity and pressure correlations of a turbulent flow. We use these equations to derive the Kadanoff-Baym equations describing the…

Fluid Dynamics · Physics 2009-08-28 Esteban Calzetta

A nonequilibrium Green's functions approach to the collective response of correlated Coulomb systems at finite temperature is presented. It is shown that solving Kadanoff-Baym type equations of motion for the two-time correlation functions…

Strongly Correlated Electrons · Physics 2009-02-11 N. -H. Kwong , M. Bonitz

A method for deriving quantum kinetic equations with initial correlations is developed on the basis of the nonequilibrium Green's function formalism. The method is applicable to a wide range of correlated initial states described by…

Statistical Mechanics · Physics 2009-10-31 V. G. Morozov , G. Röpke

A generalized quantum kinetic equation (RKE) of the Kadanoff-Baym type is obtained on the basis of the Heisenberg equations of motion where the time evolution and space translation are separated from each other by means of the covariant…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. A. Smolyansky , A. V. Prozorkevich , G. Maino , S. G. Mashnik

We propose a time-dependent many-body approach to study the short-time dynamics of correlated electrons in quantum transport through nanoscale systems contacted to metallic leads. This approach is based on the time-propagation of the…

Mesoscale and Nanoscale Physics · Physics 2011-11-28 Petri Myohanen , Adrian Stan , Gianluca Stefanucci , Robert van Leeuwen

Electron dynamics in a two-sites Hubbard model is studied using the nonequilibrium Green's function approach. The study is motivated by the empirical observation that a full solution of the integro-differential Kadanoff-Baym equation (KBE)…

Strongly Correlated Electrons · Physics 2024-01-23 Yaroslav Pavlyukh
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