## Seven Études on dynamical Keldysh model

Dmitri V. Efremov, Mikhail N. Kiselev

SciPost Phys. Lect. Notes 65 (2022) · published 6 December 2022

- doi: 10.21468/SciPostPhysLectNotes.65
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### Abstract

We present a comprehensive pedagogical discussion of a family of models describing the propagation of a single particle in a multicomponent non-Markovian Gaussian random field. We report some exact results for single-particle Green's functions, self-energy, vertex part and T-matrix. These results are based on a closed form solution of the Dyson equation combined with the Ward identity. Analytical properties of the solution are discussed. Further we describe the combinatorics of the Feynman diagrams for the Green's function and the skeleton diagrams for the self-energy and vertex, using recurrence relations between the Taylor expansion coefficients of the self-energy. Asymptotically exact equations for the number of skeleton diagrams in the limit of large $N$ are derived. Finally, we consider possible realizations of a multicomponent Gaussian random potential in quantum transport via complex quantum dot experiments.

### Cited by 1

### Authors / Affiliations: mappings to Contributors and Organizations

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^{1}Dimitri Efremov, -
^{2}Mikhail Kiselev

^{1}Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden / Leibniz Institute for Solid State and Materials Research [IFW]^{2}Centro Internazionale di Fisica Teorica Abdus Salam / Abdus Salam International Centre for Theoretical Physics [ICTP]