# gst: inertia onset in disordered porous media flow.

AA << investigate the very onset of the inertial regime in pore-scale fluid flow in a three-dimensional, disordered porous media. >>️

Their << analysis shows that the onset of inertia observed in a standard way by computing the friction factor appears at a Reynolds number two orders of magnitude higher than indicated by analyzing tortuosity and spatial distribution of kinetic energy. >>️

Damian Sniezek, Sahrish B. Naqvi, Maciej Matyka. Inertia onset in disordered porous media flow. arXiv: 2403.00456v2 [physics.flu-dyn]. Mar 26, 2024. 

https://arxiv.org/abs/2403.00456

Also: inertia, disorder, in FonT 

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

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

Keywords: gst, inertia, disorder

# ethno: cross-cultural comparison of rhythm priors in 15 countries.

<< Music is present in every known society but varies from place to place. What, if anything, is universal to music cognition? (AA) measured a signature of mental representations of rhythm in 39 participant groups in 15 countries, spanning urban societies and Indigenous populations. >>️

Their << results suggest a common feature of music cognition: discrete rhythm ‘categories’ at small-integer ratios. These discrete representations plausibly stabilize musical systems in the face of cultural transmission but interact with culture-specific traditions to yield the diversity that is evident when mental representations are probed across many cultures. >>️

Nori Jacoby, Rainer Polak, et al. Commonality and variation in mental representations of music revealed by a cross-cultural comparison of rhythm priors in 15 countries. Nat Hum Behav.  doi: 10.1038/ s41562-023-01800-9. March 4, 2024. 

https://www.nature.com/articles/s41562-023-01800-9 

Also: ethno, music, jazz, behav, in https://www.inkgmr.net/kwrds.html 

Keywords: ethno, music, jazz, behavior

# gst: Lévy flights and Lévy walks under stochastic resetting.

<< Stochastic resetting is a protocol of starting anew, which can be used to facilitate the escape kinetics. (AA)  demonstrate that restarting can accelerate the escape kinetics from a finite interval restricted by two absorbing boundaries also in the presence of heavy-tailed, Lévy-type, α

-stable noise. However, the width of the domain where resetting is beneficial depends on the value of the stability index α determining the power-law decay of the jump length distribution. For heavier (smaller α) distributions, the domain becomes narrower in comparison to lighter tails. >>

<< Additionally, (AA) explore connections between Lévy flights (LFs) and Lévy walks (LWs) in the presence of stochastic resetting. First of all, (They) show that for Lévy walks, the stochastic resetting can also be beneficial in the domain where the coefficient of variation is smaller than 1. Moreover, (They) demonstrate that in the domain where LWs are characterized by a finite mean jump duration (length), with the increasing width of the interval, the LWs start to share similarities with LFs under stochastic resetting. >>️

Bartosz Żbik, Bartłomiej Dybiec. Lévy flights and Lévy walks under stochastic resetting. Phys. Rev. E 109, 044147. April 22, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.044147

Also: keyword Lévy in FonT

https://flashontrack.blogspot.com/search?q=Lévy&m=1

Also: escape, noise, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, escape, noise, stochastic resetting, Lévy

# 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

# life: oops! AI - artificial intelligence - now beats humans at basic tasks.

<< Artificial intelligence (AI) systems, such as the chatbot ChatGPT, have become so advanced that they now very nearly match or exceed human performance in tasks including reading comprehension, image classification and competition-level mathematics, according to a new report. >>️

Nicola Jones. AI now beats humans at basic tasks — new benchmarks are needed, says major report. Stanford University’s 2024 AI Index charts the meteoric rise of artificial-intelligence tools. Nature. doi: 10.1038/ d41586-024-01087-4. Apr 15, 2024. 

https://www.nature.com/articles/d41586-024-01087-4

<< Welcome to the seventh edition of the AI Index report. The 2024 Index is our most comprehensive to date and arrives at an important moment when AI’s influence on society has never been more pronounced. >>

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THE AI INDEX REPORT. Measuring trends in AI. 

https://aiindex.stanford.edu/report/

Also:  "qui non e' impossibile immaginare ..." (here it is not impossible to imagine ... ). In: FonT. Dec 31, 2015. 

https://flashontrack.blogspot.com/2015/12/rmx-s-gst-anomalous-formation-of.html

Also:  artificial intell, analogy, nfulaw,  oops, in https://www.inkgmr.net/kwrds.html 

Keywords: life, ai, artificial intelligence, analogy, nfulaw

# 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: evolving disorder and chaos induces acceleration of elastic waves.

<< Static or frozen disorder, characterised by spatial heterogeneities, influences diverse complex systems, encompassing many-body systems, equilibrium and nonequilibrium states of matter, intricate network topologies, biological systems, and wave-matter interactions. >>

AA << investigate elastic wave propagation in a one-dimensional heterogeneous medium with diagonal disorder. (They) examine two types of complex elastic materials: one with static disorder, where mass density randomly varies in space, and the other with evolving disorder, featuring random variations in both space and time. (AA) results indicate that evolving disorder enhances the propagation speed of Gaussian pulses compared to static disorder. Additionally, (They) demonstrate that the acceleration effect also occurs when the medium evolves chaotically rather than randomly over time. The latter establishes that evolving randomness is not a unique prerequisite for observing wavefront acceleration, introducing the concept of chaotic acceleration in complex media. >>️

M. Ahumada, L. Trujillo, J. F. Marín. Evolving disorder and chaos induces acceleration of elastic waves. arXiv: 2403.02113v1 [cond-mat.dis-nn]. Mar 4, 2024. 

https://arxiv.org/abs/2403.02113

Also: waves, elastic, chaos, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, elastic, chaos, transition

# gst: exploring the on-demand dynamical generation of a plethora of dispersive shock waves arising in attractive one-dimensional droplet-bearing environment.

AA << demonstrate the controllable generation of distinct types of dispersive shock-waves emerging in a quantum droplet bearing environment with the aid of step-like initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between meanfield repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena respectively being designated by real and imaginary speed of sound. >>

<< Surprisingly, dispersive shock waves persist across the hyperbolic-to-elliptic threshold, while a plethora of additional wave patterns arise, such as rarefaction waves, traveling dispersive shock waves, (anti)kinks and droplet wavetrains. >>

AA << results pave the way for unveiling a multitude of unexplored coherently propagating waveforms in such attractively interacting mixtures. >>

Sathyanarayanan Chandramouli, Simeon I. Mistakidis, Garyfallia C. Katsimiga, Panayotis G. Kevrekidis. 

Dispersive shock waves in a one-dimensional droplet-bearing environment. arXiv: 2404.02998v2 [nlin.PS]. Apr 5, 2024. 

https://arxiv.org/abs/2404.02998

Also: waves, drop, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, drops 

# gst: apropos of evaporation, puncturing of active drops

<< By virtue of self-propulsion, active particles impart intricate stresses to the background fluids. (..) this active stress can be utilized to greatly control evaporation dynamics of active drops. >>

AA << discover a new phenomenon of puncturing of the active drops, where the air-liquid interface of the drop undergoes spontaneous tearing and there occurs a formation of a new three-phase contact line due to the liquid-air interface hitting the liquid-solid interface through evaporation-driven mass loss. Post puncturing, (AA) see an inside-out evaporation of the drop, where the new contact line sweeps towards the pinned outer contact line of the drops, contrasting regular drops that straightaway shrink to zero volume with self-similar shape. >>

<< Furthermore, (..) the activity inside the drops can manipulate the three-phase contact-line dynamics, which for contractile drops can result in an up to 50% enhanced lifetime of the drop and 33% quicker evaporation for extensile drops. By analyzing the flux distribution inside the drop, (AA) gain insights on nonintuitive deposition patterns (e.g., ring galaxy type deposits that demonstrate controllable spatial gradients in the concentrations of the deposited particles) of active particles, which are oftentimes biological substances or bimetallic nanoparticles of interest. >>

Ghansham Rajendrasingh Chandel, Vishal Sankar Sivasankar, Siddhartha Das. Evaporation of active drops: Puncturing drops and particle deposits of ring galaxy patterns. Phys. Rev. Fluids 9, 033603. Mar 27, 2024. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.9.033603

Also: drop, particle, evaporation, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drop, particle, evaporation, transition, drop interactions, droplet, droploid

# gst: creating topological vortex rings (on demand)

<< Vortex rings are ubiquitous topological structures in nature. In solid magnetic systems, their formation leads to intriguing physical phenomena and potential device applications. >>

 Here, AA << theoretically show that topological vortex rings can be created by a current pulse in a chiral magnetic nanocylinder with a trench structure. The creation process involves the formation of a vortex ring street, i.e., a chain of magnetic vortex rings with an alternative linking manner. The created vortex rings can be bounded with monopole-antimonopole pairs and possess a rich and controllable linking topology (..) which is determined by the duration and amplitude of the current pulse. >>

Yizhou Liu, Naoto Nagaosa. Current-Induced Creation of Topological Vortex Rings in a Magnetic Nanocylinder. Phys. Rev. Lett. 132, 126701. Mar 19, 2024. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.126701

Ryan Wilkinson. Magnetic Vortex Rings on Demand. Physics 17, s29. Mar 19,  2024. 

https://physics.aps.org/articles/v17/s29

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

Keywords: vortex, vortices, vortexes, vorticity, spin dynamics, spin texture, chiral magnets

# gst: elastomers fail from the edge.

<< The performance of soft devices is limited by the fracture resistance of elastomers. (..) A key observation is that thicker elastomers can be significantly tougher than thinner ones. (AA) show that this surprising toughness enhancement in thick samples emerges from the 3D geometry of the fracture process. In contrast to the classical picture of a 2D crack, failure is driven by the growth of two separate “edge” cracks that nucleate early on at a sample’s sides. As loading is increased, these cracks propagate in towards the sample midplane. When they merge, samples reach their ultimate failure strength. In thicker samples, edge cracks need to propagate farther before meeting, resulting in increased sample toughness. (AA) demonstrate that edge-crack growth is controlled by the elastomer’s strain-stiffening properties. >>

️

Nan Xue, Rong Long, Eric R. Dufresne, Robert W. Style. Elastomers Fail from the Edge. Phys. Rev. X 14, 011054. March 22, 2024. 

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011054

Also: elastic, crack, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, elastic, crack, elastomers, fracture