@phdthesis{12726,
  abstract     = {Most motions of many-body systems at any scale in nature with sufficient degrees
of freedom tend to be chaotic; reaching from the orbital motion of planets, the air
currents in our atmosphere, down to the water flowing through our pipelines or
the movement of a population of bacteria. To the observer it is therefore intriguing
when a moving collective exhibits order. Collective motion of flocks of birds, schools
of fish or swarms of self-propelled particles or robots have been studied extensively
over the past decades but the mechanisms involved in the transition from chaos to
order remain unclear. Here, the interactions, that in most systems give rise to chaos,
sustain order. In this thesis we investigate mechanisms that preserve, destabilize
or lead to the ordered state. We show that endothelial cells migrating in circular
confinements transition to a collective rotating state and concomitantly synchronize
the frequencies of nucleating actin waves within individual cells. Consequently,
the frequency dependent cell migration speed uniformizes across the population.
Complementary to the WAVE dependent nucleation of traveling actin waves, we
show that in leukocytes the actin polymerization depending on WASp generates
pushing forces locally at stationary patches. Next, in pipe flows, we study methods
to disrupt the self–sustaining cycle of turbulence and therefore relaminarize the
flow. While we find in pulsating flow conditions that turbulence emerges through a
helical instability during the decelerating phase. Finally, we show quantitatively in
brain slices of mice that wild-type control neurons can compensate the migratory
deficits of a genetically modified neuronal sub–population in the developing cortex.},
  author       = {Riedl, Michael},
  issn         = {2663-337X},
  pages        = {260},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Synchronization in collectively moving active matter}},
  doi          = {10.15479/at:ista:12726},
  year         = {2023},
}