Collective vs. single-particle motion in quantum many-body systems: Spreading and its semiclassical interpretation in the perturbative regime

The motion of a single particle under the influence of the ponderomotive force directed perpendicular to the external magnetostatic field is analysed. By solving the exact equation of motion for a specific applied electromagnetic field, the resultant ponderomotive drift is compared with the prediction of a single-particle theory using the oscillation-centre approximation. The regime of validity of this theory is discussed. It is shown that, for certain values of the amplitude and frequency of the electromagnetic field, the particle motion is unstable and therefore the concept of a single-particle ponderomotive force is meaningless.

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Feynman diagrams and rooted maps

Open Physics ◽

10.1515/phys-2018-0023 ◽

2018 ◽

Vol 16 (1) ◽

pp. 149-167 ◽

Cited By ~ 6

Author(s):

Andrea Prunotto ◽

Wanda Maria Alberico ◽

Piotr Czerski

Keyword(s):

Single Particle ◽

Feynman Diagram ◽

Feynman Diagrams ◽

Topological Properties ◽

Many Body ◽

Perturbative Order ◽

Original Definition ◽

Many Body Systems ◽

Definition Of ◽

Particle Propagator

Abstract The rooted maps theory, a branch of the theory of homology, is shown to be a powerful tool for investigating the topological properties of Feynman diagrams, related to the single particle propagator in the quantum many-body systems. The numerical correspondence between the number of this class of Feynman diagrams as a function of perturbative order and the number of rooted maps as a function of the number of edges is studied. A graphical procedure to associate Feynman diagrams and rooted maps is then stated. Finally, starting from rooted maps principles, an original definition of the genus of a Feynman diagram, which totally differs from the usual one, is given.

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Comment on "Kinetic theory of single-particle motion in a fluid"

Physical Review A ◽

10.1103/physreva.19.416 ◽

1979 ◽

Vol 19 (1) ◽

pp. 416-418 ◽

Cited By ~ 8

Author(s):

H. van Beijeren ◽

J. R. Dorfman

Keyword(s):

Kinetic Theory ◽

Single Particle ◽

Particle Motion ◽

Single Particle Motion

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A SOLVABLE MODEL OF INTERACTING MANY BODY SYSTEMS EXHIBITING A BREAKDOWN OF THE BOLTZMANN EQUATION

International Journal of Modern Physics B ◽

10.1142/s0217979214500465 ◽

2014 ◽

Vol 28 (03) ◽

pp. 1450046

Author(s):

B. H. J. McKELLAR

Keyword(s):

Boltzmann Equation ◽

Time Dependence ◽

Single Particle ◽

Density Operator ◽

Particle Density ◽

Solvable Model ◽

Many Body ◽

Single Particle Density ◽

The Boltzmann Equation ◽

Many Body Systems

In a particular exactly solvable model of an interacting system, the Boltzmann equation predicts a constant single particle density operator, whereas the exact solution gives a single particle density operator with a nontrivial time dependence. All of the time dependence of the single particle density operator is generated by the correlations.

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