# game: flocking by turning away.

<< Flocking, as paradigmatically exemplified by birds, is the coherent collective motion of active agents. As originally conceived, flocking emerges through alignment interactions between the agents. >>️

AA << report that flocking can also emerge through interactions that turn agents away from each other. >>

<< Whereas repulsion often leads to motility-induced phase separation of active particles, here it combines with turn-away torques to produce flocking. Therefore, (AA) findings bridge the classes of aligning and nonaligning active matter. (Their) results could help to reconcile the observations that cells can flock despite turning away from each other via contact inhibition of locomotion.  >>️

AA << work shows that flocking is a very robust phenomenon that arises even when the orientational interactions would seem to prevent it. >>️

️

Suchismita Das, Matteo Ciarchi, Ziqi Zhou, Jing Yan, Jie Zhang, Ricard Alert. Flocking by Turning Away. Phys. Rev. X 14, 031008. Jul 12, 2024.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.031008

Also: Janus, in FonT 

https://flashontrack.blogspot.com/search?q=janus 

Also: game, flock, in https://www.inkgmr.net/kwrds.html 

Keywords: game, flock, Janus

FonT: an approach of this type could hypothetically generate intriguing, bizarre, unexpected game scenarios in various other contexts ...

# gst: apropos of collective behaviors, a visual model to reproduces swarming, schooling, and milling.

<< Animal collective behavior is often modeled with self-propelled particles, assuming each individual has “omniscient” knowledge of its neighbors. Yet, neighbors may be hidden from view and we do not know the effect of this information loss. To address this question, (AA) propose a visual model of collective behavior where each particle moves according to bioplausible visual cues, in particular the optic flow. This visual model successfully reproduces three classical collective behaviors: swarming (no orientational order), schooling (high orientational order), and milling (the group coordinately swirls in a circular pattern). >>️

Diego Castro, Franck Ruffier, Christophe Eloy. Modeling collective behaviors from optic flow and retinal cues. Phys. Rev. Research 6, 023016. Apr 4, 2024. 

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.6.023016

Also: swarm, flock, behav, particle, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, swarming, flocking, behavior, particle, self-propelled particles

# gst: flocking transitions of unfriendly species.

AA consider << two kinds of self-propelled particles, A and B, that tend to align with particles from the same species and to antialign with the other. The model shows a flocking transition (..) it has a liquid-gas phase transition and displays micro-phase-separation in the coexistence region where multiple dense liquid bands propagate in a gaseous background. >>

<< The interesting features (..) are the existence of two kinds of bands, one composed of mainly A particles and one mainly of B particles, the appearance of two dynamical states in the coexistence region: the PF (parallel flocking) state in which all bands of the two species propagate in the same direction, and the APF (antiparallel flocking) state in which the bands of species A and species B move in opposite directions. When PF and APF states exist in the low-density part of the coexistence region they perform stochastic transitions from one to the other. The system size dependence of the transition frequency and dwell times show a pronounced crossover that is determined by the ratio of the band width and the longitudinal system size. >>

AA << work paves the way for studying multispecies flocking models with heterogeneous alignment interactions. >>

Swarnajit Chatterjee, Matthieu Mangeat, et al. Flocking of two unfriendly species: The two-species Vicsek model. Phys. Rev. E 107, 024607. Feb 14, 2023

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.107.024607 

Also

keyword 'swimmers' in FonT

https://flashontrack.blogspot.com/search?q=swimmers

Keywords: gst, flocking, particles, self-propelled particles, swimmers,  microswimmers

# behav: how (and when) multiple bird species fly and feed together, like a K-pop band

<< Birds of a feather don't always flock together: Peer into a forest canopy, and you will likely spot multiple bird species flying and feeding together, a phenomenon most spectacular in the Amazon where 50 species may travel as a unit. But are birds in these mixed flocks cooperating with one another or competing?  A new study suggests both. >>

<< Species kept competition within the flock low, however, by differentiating their foraging technique, their choice of hunting spot or the general distance they kept from a tree trunk. >>

Natalie Van Hoose. How bird flocks with multiple species behave like K-pop groups. Florida Museum of Natural History.  Feb 12, 2020

https://m.phys.org/news/2020-02-bird-flocks-multiple-species-k-pop.html

Harrison H Jones, Mitchell J Walters, Scott K Robinson. Do similar foragers flock together? Nonbreeding foraging behavior and its impact on mixed-species flocking associations in a subtropical region.  The Auk, ukz079.  doi: 10.1093/auk/ukz079. Feb 12, 2020.

https://academic.oup.com/auk/advance-article-abstract/doi/10.1093/auk/ukz079/5731484

k-pop band  

https://en.m.wikipedia.org/wiki/K-pop

# gst: inside self-organization; "swarmalators", when both synchronization and swarming occur together

<< Strogatz and O'Keeffe [Steven H. Strogatz and Kevin P. O’Keeffe], used the curious mating ritual of male Japanese tree frogs as inspiration for their exploration of "swarmalators" - their term for systems in which both synchronization and swarming occur together >>

Tom Fleischman. Mathematician's study of 'swarmalators' could direct future science. Nov 17, 2017

https://m.phys.org/news/2017-11-mathematician-swarmalators-future-science.html

<< Synchronization occurs in many natural and technological systems, from cardiac pacemaker cells to coupled lasers >>

<< A complementary form of self-organization occurs among swarming insects, flocking birds, or schooling fish >>

AA << explore systems in which both synchronization and swarming occur together. Specifically, [AA] consider oscillators whose phase dynamics and spatial dynamics are coupled >>

Kevin P. O’Keeffe, Hyunsuk Hong,  Steven H. Strogatz. Oscillators that sync and swarm.  Nature Comm 2017; 8 (1504).  doi: 10.1038/s41467-017-01190-3  Nov 15, 2017

https://www.nature.com/articles/s41467-017-01190-3

FonT

<< Amico, qualunque  cosa suonerai . . . >>  Jelly Roll Morton. cit.: 2113 - soniche a ramulo. Jan 28, 2007

http://inkpi.blogspot.it/2007/01/2113-soniche-ramulo.html

# s-gst: together, in complex flock configurations

<< Moving particles  with no memory can  group  together in complex flock configurations using only instantaneous cues >>

Flocks Without Memory. Dec. 8, 2016

https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.117.248001

Lucas Barberis, Fernando Peruani. Large-Scale Patterns in a Minimal Cognitive Flocking Model: Incidental Leaders, Nematic Patterns, and Aggregates Patterns. Phys. Rev. Lett. 117 , 248001. Publ. 6 Dec. 2016

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.248001

# rmx-s-gst: inside a chaotic, fuzzy 'active matter' ...

<< From flocking birds to swarming molecules, physicists are seeking to understand 'active matter' — and looking for a fundamental theory of the living world >>

<< We're still kind of astonished at what can happen >>

Gabriel Popkin. The physics of life. Nature 529, 16–18 (07 January 2016) doi:10.1038/529016a

http://www.nature.com/news/the-physics-of-life-1.19105