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Related papers: In memoriam Leonid V. Keldysh

200 papers

We present a generalized dynamical mean-field approach for the nonequilibrium physics of a strongly correlated system in the presence of a time-dependent external field. The Keldysh Green's function formalism is used to study the…

Strongly Correlated Electrons · Physics 2007-05-23 P. Schmidt , H. Monien

Schwinger Keldysh field theory is a widely used paradigm to study non-equilibrium dynamics of quantum many-body systems starting from a thermal state. We extend this formalism to describe non-equilibrium dynamics of quantum systems starting…

Statistical Mechanics · Physics 2019-03-13 Ahana Chakraborty , Pranay Gorantla , Rajdeep Sensarma

We examine the effective theory of critical dynamics near superfluid phase transitions in the framework of the Keldysh-Schwinger formalism. We focus on the sector capturing the dynamics of the complex order parameter and the conserved…

High Energy Physics - Theory · Physics 2024-01-31 Aristomenis Donos , Polydoros Kailidis

Using a Green's function approach, we compare the trajectories of classical Hamiltonian point particles in an expanding space-time to the effectively inertial trajectories in the Zel'dovich approximation. It is shown that the effective…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Matthias Bartelmann

Freeman J. Dyson, a brilliant theoretical physicist and a gifted mathematician, passed away on 28 February 2020 at the age of 96. A vignette of his outstanding contributions to physical sciences, ranging from the subject of quantum…

Popular Physics · Physics 2020-10-16 Patrick Das Gupta

We use the in-in or Schwinger-Keldysh formalism to explore the construction and interpretation of effective field theories for time-dependent systems evolving out of equilibrium. Starting with a simple model consisting of a heavy and a…

High Energy Physics - Theory · Physics 2015-06-11 Hael Collins , R. Holman , Andreas Ross

The formalism of nonequilibrium perturbation theory was constructed by Schwinger and Keldysh and then was developed with the diagrammatical technique by Lifshitz and Pitaevskii. Until now there has been widespread application to various…

Mesoscale and Nanoscale Physics · Physics 2008-02-06 Mami Hamasaki

We compute the current and the noise power matrix in a quantum dot connected to two metallic reservoirs by using the Keldysh field theory approach, a non-equilibrium quantum field theory language in the functional integral formalism. We…

Mesoscale and Nanoscale Physics · Physics 2024-11-20 Marco Uguccioni , Luca Dell'Anna

In November 2014 Alexander Grothendieck passed away at the age of 86. There is no doubt that he was one of the greatest and most innovative mathematicians of the 20th century. After a bitter childhood, his meteoric ascent started in the…

History and Overview · Mathematics 2016-05-27 Wolfgang Bietenholz , Tatiana Peixoto

Peter Higgs was a British theoretical physicist, famous for his work published in 1964, where he proposed a mechanism that can generate masses for elementary particles, while respecting gauge invariance. Half a century later, two…

Popular Physics · Physics 2024-06-25 Wolfgang Bietenholz , José Antonio García-Hernández

We present a theory for the Kondo spin-1/2 effect in strongly correlated quantum dots. The theory is applicable at any temperature and voltage. It is based on a quadratic Keldysh effective action parameterized by a universal function. We…

Mesoscale and Nanoscale Physics · Physics 2013-03-14 Sergey Smirnov , Milena Grifoni

We describe microscopic theory for the quantum transport through finite interacting systems connected to noninteracting leads. It can be applied to small systems such as quantum dots, quantum wires, atomic chain, molecule, and so forth. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Akira Oguri

It is shown how to construct Keldysh diagram technique for pseudo - particle approach to the Hubbard model. We propose self consistent equations for pseudo particle and electron Green functions in Keldysh diagram technique. Nonlocal effects…

Strongly Correlated Electrons · Physics 2014-08-27 P. I. Arseyev , N. S. Maslova

A generalized Landauer formula, derived with the methods due to Keldysh, and Baym and Kadanoff, is gaining widespread use in the modeling of transport in a large number of different mesoscopic systems. We review some of the recent…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 Antti-Pekka Jauho

These twenty-two lectures, with exercises, comprise the extent of what was meant to be a full-year graduate-level course on the strong interactions and QCD, given at Pactech in 19$xx$-$xy$. The course was cut short by the illness that led…

High Energy Physics - Phenomenology · Physics 2023-04-28 Robert P. Finemensch , Gerald X. Gilbert-Thorple

Recent experimental developments in diverse areas - ranging from cold atomic gases over light-driven semiconductors to microcavity arrays - move systems into the focus, which are located on the interface of quantum optics, many-body physics…

Quantum Gases · Physics 2016-08-05 L. M. Sieberer , M. Buchhold , S. Diehl

We present an implementation of the steady state Keldysh approach in a Green's function multiple scattering scheme to calculate the non-equilibrium spin density. This density is used to obtain the spin transfer torque in junctions showing…

Mesoscale and Nanoscale Physics · Physics 2008-02-13 Christian Heiliger , Michael Czerner , Bogdan Yu. Yavorsky , Ingrid Mertig , Mark D. Stiles

We introduce a quasiclassical Green function approach describing the unitary yet irreversible dynamics of quantum systems effectively acting as their own environment. Combining a variety of concepts of quantum many-body theory, notably the…

Mesoscale and Nanoscale Physics · Physics 2025-09-09 Alexander Altland , Kun Woo Kim , Tobias Micklitz

We study the 4-point function in the Keldysh formalism of the closed time path formulation of real time finite temperature field theory. We derive the KMS conditions for these functions and discuss the number of 4-point functions that are…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. E. Carrington , Hou Defu , J. C. Sowiak

Lev Davidovich Landau was arguably one of the greatest and most versatile physicists. His work spans a very wide range and has had a considerable impact on all areas of physics including condensed matter physics, plasma, high energy and…

General Physics · Physics 2011-05-05 C Sivaram , Kenath Arun