https://doi.org/10.1140/epjc/s10052-022-10914-9
Regular Article - Theoretical Physics
Early time behavior of spatial and momentum anisotropies in kinetic theory across different Knudsen numbers
Fakultät für Physik, Universität Bielefeld, D-33615, Bielefeld, Germany
a
borghini@physik.uni-bielefeld.de
Received:
8
February
2022
Accepted:
13
October
2022
Published online:
29
October
2022
We investigate the early time development of the anisotropic transverse flow and spatial eccentricities of a fireball with various particle-based transport approaches using a fixed initial condition. In numerical simulations ranging from the quasi-collisionless case to the hydrodynamic regime, we find that the onset of 
and of related measures of anisotropic flow can be described with a simple power-law ansatz, with an exponent that depends on the amount of rescatterings in the system. In the few-rescatterings regime we perform semi-analytical calculations, based on a systematic expansion in powers of time and the cross section, which can reproduce the numerical findings.
© The Author(s) 2022
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