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Optimum trajectories in a central force field
Optimum trajectories in central force fiel
Lagrangian Investigation of Two-Dimensional Decaying Turbulence
We present a numerical investigation of two-dimensional decaying turbulence
in the Lagrangian framework. Focusing on single particle statistics, we
investigate Lagrangian trajectories in a freely evolving turbulent velocity
field. The dynamical evolution of the tracer particles is strongly dominated by
the emergence and evolution of coherent structures. For a statistical analysis
we focus on the Lagrangian acceleration as a central quantity. For more
geometrical aspects we investigate the curvature along the trajectories. We
find strong signatures for self-similar universal behavior
Local dynamics in high-order harmonic generation using Bohmian trajectories
We investigate high-order harmonic generation from a Bohmian-mechanical
perspective, and find that the innermost part of the core, represented by a
single Bohmian trajectory, leads to the main contributions to the high-harmonic
spectra. Using time-frequency analysis, we associate this central Bohmian
trajectory to an ensemble of unbound classical trajectories leaving and
returning to the core, in agreement with the three step model. In the Bohmian
scenario, this physical picture builds up non-locally near the core via the
quantum mechanical phase of the wavefunction. This implies that the flow of the
wavefunction far from the core alters the central Bohmian trajectory. We also
show how this phase degrades in time for the peripheral Bohmian trajectories as
they leave the core region.Comment: 7 pages, 3 figures; the manuscript has been considerably extended and
modified with regard to the previous version
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