# gst: apropos of synchronization of large bubble clouds, self-oscillating acoustic bubbles that bounce

<< Self-oscillations underlie many natural phenomena such as heartbeat, ocean waves, and the pulsation of variable stars. (..) In this study, (AA) consider two closely spaced bubbles pulsating in the kHz range in response to ultrasonic excitation. A translational bouncing motion emerges from their interaction with a much lower frequency than the bubble pulsation frequency. >>

Their analysis << reveals that the observed bubble bouncing exhibits the main features of self-oscillation, such as negative damping and the emergence of a limit cycle. These results highlight unexpected nonlinear effects in the field of microbubbles and give insights into the understanding of synchronization in large bubble clouds. >>️

Gabriel Regnault, Alexander A Doinikov, et al. Phenomenon of self-oscillation in bubble dynamics: Bouncing acoustic bubbles. arXiv: 2404.05822v1 [physics.flu-dyn]. Apr 8, 2024.

https://arxiv.org/abs/2404.05822

Also: bubble, bouncing, behav, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubble, self-oscillation, bouncing, behavior, collective behavior, bouncing motion, synchronization

# gst: emergence of chimeras driven by non-normality

<< The emergence of order in nature manifests in different phenomena, with synchronization being one of the most representative examples. >>️

<< Particular attention has been paid to the emergence of chimera states, where subsets of synchronized oscillations coexist with asynchronous ones. Such coexistence of coherence and incoherence is a perfect example where order and disorder can persist in a long-lasting regime. >>

<< Based on a symmetry-breaking mechanism, in this paper, (AA) shed light on the role that non-normality, a ubiquitous structural property of real networks, has in the emergence of several diverse dynamical phenomena, e.g., amplitude chimeras or oscillon patterns. >>️

<< Specifically, (they) demonstrate that the prevalence of source or leader nodes in networks leads to the manifestation of phase chimera states. >>️

Riccardo Muolo, Joseph D. O'Brien, et al. Persistence of chimera states and the challenge for synchronization in real-world networks. arXiv: 2306.00237v1 [nlin.PS]. May 31, 2023.

https://arxiv.org/abs/2306.00237

Also: chimera, network, in: https://www.inkgmr.net/kwrds.html

Keywords: gst, chimera, network, synchronization, swarm, noise, order, disorder, normal

# s-gst: lastly, they indicate the generality of that

<< Lastly, [AA] indicate the generality of this phenomenon by demonstrating suppression of chaotic oscillations by coupling to a common hyper-chaotic system. These results then indicate the easy controllability of chaotic oscillators by an external chaotic system, thereby suggesting a potent method that may help design control strategies. >>

Sudhanshu Shekhar Chaurasia, Sudeshna Sinha. Suppression of chaos through coupling to an external chaotic system. 2 Jul 2016.

https://arxiv.org/abs/1607.00462

also: https://arxiv.org/find/all/1/all:+AND+suppression+chaos/0/1/0/all/0/1

# brain: chaotic scanning and tiny wobbles during (ocular) vision

<< When we read, our eyes don’t scan a page smoothly but perform a series of jumps, darting from one section of text to another. After each jump, known as a saccade, the pupil typically wobbles for a moment. Now researchers have developed a model for this wobble that involves only physical characteristics of the eyeball >>

Why Your Pupils Wobble. Apr 27, 2018

https://physics.aps.org/articles/v11/41

Bouzat S, Freije ML, et al. Inertial Movements of the Iris as the Origin of Postsaccadic Oscillations. Phys Rev  Lett. 120, 178101. doi: 10.1103/PhysRevLett.120.178101 Apr 27, 2018.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.178101

Also

2146 - is not as simple as one might think (chaos in reading). Sep11, 2007.

http://inkpi.blogspot.it/2007/09/2146-is-not-as-simple-as-one-might.html

# gst: weird matter, the 'ballistic resonance' paradox; amplitude of mechanical vibrations can grow without external influence

AA << discovered a new physical phenomenon of 'ballistic resonance', where mechanical oscillations can be excited only due to internal thermal resources of the system. >>

<< The discovered phenomenon describes that the process of heat equilibration leads to mechanical vibrations with an amplitude that grows with time. The effect is called ballistic resonance. >>

<< Over the past few years, our scientific group has been looking into the mechanisms of heat propagation at the micro and nano levels. We found out that at these levels, heat doesn't spread in the way we expected it to: for example, heat can flow from cold to hot. This behavior of nanosystems leads to new physical effects, such as ballistic resonance, >> Vitaly Kuzkin.

Scientists have discovered a new physical paradox. Peter the Great Saint-Petersburg Polytechnic University. Jul 13, 2020.

https://phys.org/news/2020-07-scientists-physical-paradox.html

<< coupling between macroscopic dynamics and quasiballistic heat transport gives rise to mechanical vibrations with growing amplitude. This phenomenon is referred to as ballistic resonance. At large times, these mechanical vibrations decay monotonically >>

Vitaly A. Kuzkin, Anton M. Krivtsov. 

Ballistic resonance and thermalization in the Fermi-Pasta-Ulam-Tsingou chain at finite temperature. Phys. Rev. E 101, 042209. Apr 16, 2020.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.101.042209