# gst: when a phase transition could be controlled by a fixed point of infinite disorder

AA << apply a real-space block renormalization group approach to study the critical properties of the random transverse-field Ising spin chain with multispin interactions. First (They) recover the known properties of the traditional model with two-spin interactions by applying the renormalization approach for arbitrary size of the block. For the model with three-spin couplings (They) calculate the critical point and demonstrate that the phase transition is controlled by an infinite disorder fixed point. (AA) have determined the typical correlation-length critical exponent, which seems to be different from that of the random transverse Ising chain with nearest-neighbor couplings. Thus this model represents a new infinite disorder universality class. >>️

Ferenc Iglói, Yu-Cheng Lin. Random quantum Ising model with three-spin couplings. arXiv:2503.18690v1 [cond-mat.dis-nn]. Mar 24, 2025.

https://arxiv.org/abs/2503.18690

Also: disorder, order, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, order, transition

# life: and so the short run matters, by John.

<<  Good Wednesday morning, and happy Liberation Day. This is Jack Blanchard, off to panic-buy Yorkshire Tea and Scotch whisky before the tariffs kick in.  >>️

<<  Fears on the Hill: In particular, the numerous free-traders in the GOP’s ranks on the Hill are feeling pretty darn uncomfortable about what’s coming. Sen. John Kennedy (R-La.) said he hopes the president’s plan is ultimately to use the threat of tariffs to force other nations to strip back their own. “In the long run, [it] will probably work,” he said. “The problem is that in the long run, we’re all dead. And so the short run matters.”  >>

Jack Blanchard. A message to Musk. Politico. Playbook. Apr 02, 2025. 

https://www.politico.com/newsletters/playbook/2025/04/02/a-message-to-musk-00265583  

Also: Mr. Donald, Mr. Vlad, Mr. Chen, RAG-time, triptych, crack, in https://www.inkgmr.net/kwrds.html 

Keywords: life, Mr. Donald, Mr. Vlad, Mr. Chen, RAG-time, triptych, crack

# epidem: societal self-regulation appears to induce complex infection dynamics and chaos.

<< Classically, endemic infectious diseases are expected to display relatively stable, predictable infection dynamics. Accordingly, basic disease models such as the susceptible-infected-recovered-susceptible model display stable endemic states or recurrent seasonal waves. However, if the human population reacts to high infection numbers by mitigating the spread of the disease, then this delayed behavioral feedback loop can generate infection waves itself, driven by periodic mitigation and subsequent relaxation. >>

AA << show that such behavioral reactions, together with a seasonal effect of comparable impact, can cause complex and unpredictable infection dynamics, including Arnold tongues, coexisting attractors, and chaos. >>

<< Importantly, these arise in epidemiologically relevant parameter regions where the costs associated to infections and mitigation are jointly minimized. By comparing (Their) model to data, (AA) find signs that COVID-19 was mitigated in a way that favored complex infection dynamics. (AA)  results challenge the intuition that endemic disease dynamics necessarily implies predictability and seasonal waves and show the emergence of complex infection dynamics when humans optimize their reaction to increasing infection numbers. >>️

Joel Wagner, Simon Bauer, et al.  Societal self-regulation induces complex infection dynamics and chaos. Phys. Rev. Research 7, 013308. Mar 24, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.7.013308

Also: virus, sars* covid* (aka 1or2achoos), waves, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: epidemiology, virus, sars, covid-19, chaos

# gst: synchronization and chaos in complex systems with delayed interactions.

<< Explaining the wide range of dynamics observed in ecological communities is challenging due to the large number of species involved, the complex network of interactions among them, and the influence of multiple environmental variables. >>

AA << consider a general framework to model the dynamics of species-rich communities under the effects of external environmental factors, showing that it naturally leads to delayed interactions between species, and analyze the impact of such memory effects on population dynamics. >>

<< Employing the generalized Lotka-Volterra equations with time delays and random interactions, (AA) characterize the resulting dynamical phases in terms of the statistical properties of community interactions. (Their) findings reveal that memory effects can generate persistent and synchronized oscillations in species abundances in sufficiently competitive communities. This provides an additional explanation for synchronization in large communities, complementing known mechanisms such as predator-prey cycles and environmental periodic variability. >>

<< Furthermore, (AA) show that when reciprocal interactions are negatively correlated, time delays alone can induce chaotic behavior. This suggests that ecological complexity is not a prerequisite for unpredictable population dynamics, as intrinsic memory effects are sufficient to generate long-term fluctuations in species abundances. >>

Francesco Ferraro, Christian Grilletta, et al. Synchronization and chaos in complex ecological communities with delayed interactions. arXiv: 2503.21551v1 [q-bio.PE]. Mar 27, 2025.

https://arxiv.org/abs/2503.21551

Also: pause, silence, random, chaos, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, pause, silence, random, chaos, chaotic behavior, network, delay, time delay, delayed interactions, random interactions, memory effect 

# gst: apropos of multiple delays, transitions to intermittent chaos in quorum sensing-inspired dynamics.

<< This study analyses the dynamical consequences of heterogeneous temporal delays within a quorum sensing-inspired (QS-inspired) system, specifically addressing the differential response kinetics of two subpopulations to signalling molecules. >>️

<< The analysis reveals the critical role of multiple, dissimilar delays in modulating system dynamics and inducing bifurcations. Numerical simulations, conducted in conjunction with analytical results, reveal the emergence of periodic self-sustained oscillations and intermittent chaotic behaviour. These observations emphasise the intricate relationship between temporal heterogeneity and the stability landscape of systems exhibiting QS-inspired dynamics. This interplay highlights the capacity for temporal variations to induce complex dynamical transitions within such systems. >>️

AA << findings show that the presence of multiple delays, particularly when characterised by significant disparities in magnitude, can dramatically alter the system’s stability features and promote the emergence of complex nonlinear oscillatory behaviour. >>️

<< Upon explicitly incorporating distinct delays for different state-components, (AA) have shown how temporal factors can dramatically influence system stability and give rise to a spectrum of complex dynamical behaviours, including intermittent chaos. >>

Anahí Flores, Marcos A. González, Víctor F. Breña-Medina. Transitions to Intermittent Chaos in Quorum Sensing Dynamics. arXiv: 2503.14363v2 [nlin.CD]. Mar 19, 2025.

https://arxiv.org/abs/2503.14363

Also: intermittency, pause, silence, transition, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, intermittency, pause, silence, transitions, chaos 

# gst: noise as endogenous control

<< Systems biology faces the monumental task of synthesizing vast amounts of molecular facts into a cohesive whole. While it is recognized that stochasticity is ubiquitous in the cell, with noise playing a role in gene expression, differentiation, and switching (..), it is still commonly argued that the cell functions in spite of the noisy cellular environment. >>️

<< Stochastic systems have a control-theoretic interpretation in which noise plays the role of endogenous control. In the weak-noise limit, relevant at low temperatures or in large populations, control is optimal and an exact mathematical mapping from noise to control is described, where the maximizing the probability of a state becomes the control objective. >>

<< In Langevin dynamics noise is identified directly with control, while in general Markov jump processes, which include chemical reaction networks and electronic circuits, (AA) use the Doi-Zel'dovich-Grassberger-Goldenfeld-Peliti path integral to identify the `response' or `tilt' field π as control, which is proportional to the noise in the semiclassical limit. This solves the longstanding problem of interpreting π. >>

AA << illustrate the mapping on multistable chemical reaction networks and systems with unstable fixed points. The noise-control mapping builds intuition for otherwise puzzling phenomena of stochastic systems: why the probability is generically a non-smooth function of state out of thermal equilibrium; why biological mechanisms can work better in the presence of noise; and how agentic behavior emerges naturally without recourse to mysticism. >>

Eric De Giuli. Noise equals endogenous control. arXiv: 2503.15670v2 [q-bio.MN]. Mar 24, 2025.

https://arxiv.org/abs/2503.15670

Also: noise, disorder & fluctuations, transition, dance, jazz, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, noise, disorder, transition, ethno, crosstalk, gossip, misinformation, fake news, dance, jazz

# gst: odd electrical circuits

<< Non-reciprocal interactions in elastic media give rise to rich non-equilibrium behaviors, but controllable experimental realizations of such odd elastic phenomena remain scarce. Building on recent breakthroughs in electrical analogs of non-Hermitian solid-state systems, (AA) design and analyze scalable odd electrical circuits (OECs) as exact analogs of an odd solid. >>

AA << show that electrical work can be extracted from OECs via cyclic excitations and trace the apparent energy gain back to active circuit elements. (They) show that OECs host oscillatory modes that resemble recent experimental observations in living chiral crystals and identify active resonances that reveal a perspective on odd elasticity as a mechanism for mechanical amplification. >>️

Harry Walden, Alexander Stegmaier, et al. Odd electrical circuits. arXiv: 2503.14383v1 [cond-mat.soft]. Mar 18, 2025.

https://arxiv.org/abs/2503.14383

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

Keywords: gst, chirality, chiral crystals, chiral oscillations, chiral waves, oddity, odd elastic materials

# gst: droplet bag formation in turbulent airflows.

AA << present numerical simulations investigating the evolution of liquid droplets into baglike structures in turbulent airflows. The droplet bag breakup problem is of significance for many multiphase processes in scientific and engineering applications. Turbulent fluctuations are introduced synthetically into a mean flow, and the droplet is inserted when the air-phase turbulence reaches a statistically stationary state. The morphological evolution of the droplet under different turbulence configurations is retrieved and analyzed in comparison with laminar aerobreakup results. While the detailed evolution history of individual droplets varies widely between different realizations of the turbulent flow, common dynamic and morphological evolution patterns are observed. >>

<< The presence of turbulence is found to enhance the drag coefficient of the droplet as it flattens. At late times, the droplet becomes tilted and increasingly corrugated under strong turbulence intensity. (AA) quantify these phenomena and discuss their possible governing mechanisms associated with turbulence intermittency. >>

<< Lastly, the influences of liquid-gas viscosity ratio are examined and the implications of air-phase turbulence on the later bag film breakup process are discussed. >>️

Kaitao Tang, Thomas A. A. Adcock, Wouter Mostert. Droplet bag formation in turbulent airflows. Phys. Rev. Fluids 10, 033604. March 19, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.10.033604

Also: drop, droplet, droploid, turbulence, fluctuations, intermittency, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drop, droplet, droploid, turbulence, fluctuations, intermittency

# gst: from alternating stripes to alternating labyrinths, the Belousov−Zhabotinsky transition

<< Alternating (temporally period-2) stripes and labyrinths have been observed in media of chemical and biochemical reactions; however, the mechanisms underlying the formation of these spatiotemporal patterns remain unclear. >>

AA << conduct computer simulation using a modified model of Belousov−Zhabotinsky reaction that incorporates a global feedback loop with a spatial strength profile of Gaussian distribution. The simulation results demonstrate that the transition from alternating stripes to alternating labyrinths occurs when the feedback is negative with a certain width of the Gaussian function. (AA) add the same Gaussian-weighted feedback loop to an amplitude equation to describe the amplitude dynamics of the period-2 oscillation and show that the pattern dynamics of the Belousov−Zhabotinsky reaction can be well captured by this amplitude equation. >>

<< Analyses of the amplitude equation demonstrate that the transition from stripes to labyrinths arises from the transverse instabilities of bistable fronts caused by the Gaussian-weighted negative global feedback. >>️

Chunli Huang, Zhen Song, Zhilin Qu. Transition from alternating stripes to alternating labyrinths in oscillatory media. Phys. Rev. E 111, L032201. Mar 13, 2025.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.111.L032201

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

Also: Orologio chimico. Notes (quasi-stochastic poetry). Apr 08, 2005.

https://inkpi.blogspot.com/2005/04/1558-orologio-chimico.html  

Keywords: gst, transitions, BZ reaction, labyrinths, alternating labyrinths

# gst: First-passage-time statistics of active Brownian particles: a perturbative approach.

AA << study the first-passage-time (FPT) properties of active Brownian particles to reach an absorbing wall in two dimensions. Employing a perturbation approach (They) obtain exact analytical predictions for the survival and FPT distributions for small Péclet numbers, measuring the importance of self-propulsion relative to diffusion. >>

<< While randomly oriented active agents reach the wall faster than their passive counterpart, their initial orientation plays a crucial role in the FPT statistics. Using the median as a metric, (AA) quantify this anisotropy and find that it becomes more pronounced at distances where persistent active motion starts to dominate diffusion. >>️

Yanis Baouche, Magali Le Goff, et al. First-passage-time statistics of active Brownian particles: a perturbative approach. arXiv: 2503.05401v1 [cond-mat.soft]. Mar 7, 2025.

https://arxiv.org/abs/2503.05401

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

Keywords: gst, particles, active particles, perturbation approach, randomness, stochasticity, stochastic resetting, rotational diffusion, anisotropy

# poe: onda di gioco

<<  

Nota a far mescole coll' endogeno docile avo melode /

declamando su traccia nevale di dondolio di geco /

l' evento d' onde nella forma di compressa logica ode /

che, se liberata, s' autoespande in frange d' agile eco.

>>

14.31 13/09/2004

'solebat quid esset litus ita definire: "qua fluctus eluderet"'. In: Cicerone. 'de natura deorum'.

https://inkpi.blogspot.com/2005/03/1782-onda-di-gioco.html  

Anche:  waves, in   

Notes (quasi-stochastic poetry)  https://inkpi.blogspot.com/search?q=onda 

FonT  https://flashontrack.blogspot.com/search?q=waves 

inkgmr.net  https://www.inkgmr.net/kwrds.html 

Anche: World Poetry Day, in

 https://en.m.wikipedia.org/wiki/World_Poetry_Day     https://nationaltoday.com/world-poetry-day

Keywords: poe, poetry, quasi-stochastic poetry, PoetryDay, WorldPoetryDay, InternationalPoetryDay, waves, rogue waves, shock waves, solitons, turbulence, instability

# aibot: I think, therefore I hallucinate: minds, machines, and the art of being wrong.

<< This theoretical work examines 'hallucinations' in both human cognition and large language models, comparing how each system can produce perceptions or outputs that deviate from reality. Drawing on neuroscience and machine learning research, (AA) highlight the predictive processes that underlie human and artificial thought. >>

<< In humans, complex neural mechanisms interpret sensory information under uncertainty, sometimes filling in gaps and creating false perceptions. This inference occurs hierarchically: higher cortical levels send top-down predictions to lower-level regions, while mismatches (prediction errors) propagate upward to refine the model. LLMs, in contrast, rely on auto-regressive modeling of text and can generate erroneous statements in the absence of robust grounding. >>

<< Despite these different foundations - biological versus computational - the similarities in their predictive architectures help explain why hallucinations occur. (AA) propose that the propensity to generate incorrect or confabulated responses may be an inherent feature of advanced intelligence. In both humans and AI, adaptive predictive processes aim to make sense of incomplete information and anticipate future states, fostering creativity and flexibility, but also introducing the risk of errors. (Their) analysis illuminates how factors such as feedback, grounding, and error correction affect the likelihood of 'being wrong' in each system. (AA) suggest that mitigating AI hallucinations (e.g., through improved training, post-processing, or knowledge-grounding methods) may also shed light on human cognitive processes, revealing how error-prone predictions can be harnessed for innovation without compromising reliability. By exploring these converging and divergent mechanisms, the paper underscores the broader implications for advancing both AI reliability and scientific understanding of human thought. >>️

Sebastian Barros. I Think, Therefore I Hallucinate: Minds, Machines, and the Art of Being Wrong. arXiv: 2503.05806v1 [q-bio.NC]. 4 Mar 4, 2025.

https://arxiv.org/abs/2503.05806

Also: brain, curiosity, novelty, uncertainty, error, mistake, jazz, ai (artificial intell), in https://www.inkgmr.net/kwrds.html 

Keywords: brain, cognition, perceptions, curiosity, novelty, hallucinations, errors, prediction, prediction errors, error-prone predictions, AI, artificial intelligence, LLMs

# behav: the benefit of ignorance for traffic through a random congestible network.

<< When traffic is routed through a network that is susceptible to congestion, the self-interested decisions made by individual users do not, in general, produce the optimal flow. This discrepancy is quantified by the so-called "price of anarchy." >>

AA << consider whether the traffic produced by self-interested users is made better or worse when users have uncertain knowledge about the cost functions of the links in the network, and define a parallel concept that (They) call the "price of ignorance."  >>

AA << introduce a simple model in which fast, congestible links and slow, incongestible links are mixed randomly in a large network and users plan their routes with finite uncertainty about which of the two cost functions describes each link. >>

<< One of (Their) key findings is that a small level of user ignorance universally improves traffic, regardless of the network composition. Further, there is an optimal level of ignorance which, in (the) model, causes the self-interested user behavior to coincide with the optimum. Many features of (AA) model can be understood analytically, including the optimal level of user ignorance and the existence of critical scaling near the percolation threshold for fast links, where the potential benefit of user ignorance is greatest. >>️

Alican Saray, Calvin Pozderac, et al. The benefit of ignorance for traffic through a random congestible network. arXiv: 2503.09684v1 [cond-mat.dis-nn]. Mar 12, 2025.

https://arxiv.org/abs/2503.09684

Also:  network, behav, random, uncertainty, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, networks, behavior,  randomness, uncertainty, price of anarchy, price of ignorance

# qubit: stability of classical shadows under gate-dependent noise

<< Expectation values of observables are routinely estimated using so-called classical shadows—the outcomes of randomized bases measurements on a repeatedly prepared quantum state. In order to trust the accuracy of shadow estimation in practice, it is crucial to understand the behavior of the estimators under realistic noise. >>

<< In this Letter, (AA) prove that any shadow estimation protocol involving Clifford unitaries is stable under gate-dependent noise for observables with bounded stabilizer norm—originally introduced in the context of simulating Clifford circuits. In contrast, (They) demonstrate with concrete examples that estimation of “magic” observables can lead to highly misleading results in the presence of miscalibration errors and a worst case bias scaling exponentially in the system size. >>

AA << further find that so-called robust shadows, aiming at mitigating noise, can introduce a large bias in the presence of gate-dependent noise compared to unmitigated classical shadows. Nevertheless, (AA) guarantee the functioning of robust shadows for a more general noise setting than in previous works. On a technical level, (They) identify average noise channels that affect shadow estimators and allow for a more fine-grained control of noise-induced biases. >>️

Raphael Brieger, Markus Heinrich, et al. Stability of Classical Shadows under Gate-Dependent Noise. Phys. Rev. Lett. 134, 090801. Mar 4, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.090801  arXiv: 2310.19947v3 [quant-ph]. Feb 19, 2025.   https://arxiv.org/abs/2310.19947

Also: qubit, in FonT  https://flashontrack.blogspot.com/search?q=qubit  noise, ai (artificial intell) (bot), in https://www.inkgmr.net/kwrds.html   

Keywords: qubit, noise, realistic noise, shadows, robust shadows

# gst: apropos of degeneration, the topological degeneracy induced by twisting.

<< In recent years, twisting has emerged as a new degree of freedom that plays an increasingly important role in Bloch bands of various physical systems. However, there is currently a lack of reports on the nontrivial physics of topological degeneracy in twisted systems. >>

AA << investigated the intrinsic physical correlation between twisting and topological degeneracy. (They) found that twisting not only breaks the symmetry of the system but also introduces topological degeneracy that does not exist under the original symmetric system without twisting. >>

<< Furthermore, the topological degeneracy can be easily tuned through twisting. This new twist-induced topological degeneracy gives rise to a unique polarization-degenerate birefringent medium, wherein the twist angle acts as a novel degree of freedom for dispersion and polarization management of interface states. >> 

<< Exhibiting fascinating properties and experimental feasibilities, (AA) Letter points to new possibilities in the research of various topological physics in twisted photonics. >>️

Han Peng, Qiang Wang, et al. Topological degeneracy induced by twisting. Phys. Rev. Lett. 134, 106601. Mar 11, 2025.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.106601   arXiv: 2503.09048v1 [physics.optics]. https://arxiv.org/abs/2503.09048  

Also: degeneration, in FonT https://flashontrack.blogspot.com/search?q=degeneration   twisting, twist, in FonT   https://flashontrack.blogspot.com/search?q=twisting    https://flashontrack.blogspot.com/search?q=twist 

Keywords: gst, degeneration, twisting 

# qubit: communication power of a noisy qubit.

<< A fundamental limitation of quantum communication is that a single qubit can carry at most one bit of classical information. For an important class of quantum communication channels, known as entanglement breaking, this limitation holds even if the sender and receiver share entangled particles. But does this mean that, for the purpose of communicating classical messages, a noisy entanglement-breaking qubit channel can be replaced by a noisy bit channel? >>

Here AA << answer the question in the negative. (They) introduce a game, similar to the Monty Hall problem in classical statistics, where a sender assists a receiver in finding a valuable item (the “prize”) hidden in one of four possible boxes, while avoiding a hazardous item (the “bomb”) hidden in one of the remaining three boxes. (AA) show that no classical strategy using a noisy bit channel can ensure that the bomb is avoided, even if the sender and receiver share arbitrary amounts of randomness. >>

<< In contrast, communication of a qubit through a class of noisy entanglement-breaking channels, which (They) call quantum not channels, allows the players to deterministically avoid the bomb and to find the prize with a guaranteed nonzero probability. >>

AA << findings show that the communication of classical messages through a noisy entanglement-breaking qubit channel assisted by quantum entanglement cannot, in general, be simulated by communication through a noisy bit channel assisted by classical correlations. >>️

Giulio Chiribella, Saptarshi Roy, et al. Communication Power of a Noisy Qubit. Phys. Rev. Lett. 134, 080803. Feb 28, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.080803     arXiv: 2405.17946v2 [quant-ph]. https://arxiv.org/abs/2405.17946  

Also: qubit, in https://flashontrack.blogspot.com/search?q=qubit  game, in  https://flashontrack.blogspot.com/search?q=game  noise, in  https://flashontrack.blogspot.com/search?q=noise 

Keywords: qubit, games, noise

# gst: dynamics of fluid-driven fractures across material heterogeneities.

<< Fracture propagation is highly sensitive to the conditions at the crack tip. In heterogeneous materials, microscale obstacles can cause propagation instabilities. Macroscopic heterogeneities modify the stress field over scales larger than the tip region. >>

 Here AA << experimentally investigate the propagation of fluid-driven fractures through multilayered materials. (They) focus on analyzing fracture profiles formed upon injection of a low-viscosity fluid into a two-layer hydrogel block. >>

<< Experimental observations highlight the influence of the originating layer on fracture dynamics. Fractures that form in the softer layer are confined, with no penetration in the stiffer layer. Conversely, fractures initiated within the stiffer layer experience rapid fluid transfer into the softer layer when reaching the interface. >>

AA << report the propagation dynamics and show that it is controlled by the toughness contrast between neighboring layers, which drives fluid flow. (They) model the coupling between elastic deformation, material toughness, and volume conservation. After a short transient regime, scaling arguments capture the dependence of the fracture geometry on material properties, injection parameters, and time. These results show that stiffness contrast can modify fracture propagation over large length scales and demonstrate the importance of macroscopic scale heterogeneities on fracture dynamics. >>

Sri Savya Tanikella, Marie C. Sigallon, Emilie Dressaire. Dynamics of fluid-driven fractures across material heterogeneities. Phys. Rev. E 111, 025504. Feb 28, 2025.   https://journals.aps.org/pre/abstract/10.1103/PhysRevE.111.025504     arXiv: 2407.10298v1 [physics.flu-dyn]. Jul 14, 2024.  https://arxiv.org/abs/2407.10298

Also: fracture, crack, elastic, 

instability, disorder, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, fracture, crack, elasticity, instability, disorder, transitions

# gst: tandem droplets accelerated by continuous uniform airflow.

<< In a dense droplet environment, droplets influence each other's motion, deformation, and breakup behavior. The tandem droplet is a particularly relevant case for the study of its unsteady dynamic behavior. >>

<< A three-dimensional numerical simulation study was conducted to investigate the deformation process of tandem droplets under different conditions. >>

<< The results of the research show that under conditions of high density ratio and a significant Reynolds number, the edge morphological characteristics of droplets are predominantly influenced by the Rayleigh-Taylor instability. In the case of low density ratios, the pressure drag force on the leeward side exerts a dominant influence on the accelerated motion of the leading droplet. The shape of the droplet is significantly influenced by the vortex ring present in the recirculation region. The perturbation of the liquid edge induces the vortex ring to split into secondary vortex rings, which act back on the droplet, thereby affecting its morphological characteristics. The trailing droplet is subject to a reduction in cross-flow radius, drag coefficient, minimum length, and expansion speed of the liquid bag due to the influence of the wake of the leading droplet. The decrease in Reynolds number and relative distance leads to a stronger suppression effect, while the decrease in density ratio shortens the length of the recirculation region, thereby weakening the suppression of trailing droplets. >>

Shuting Peng, Fuzhen Chen, et al. Three-dimensional numerical simulation of tandem droplets accelerated by continuous uniform airflow. Phys. Rev. Fluids 10, 024304. Feb 25, 2025. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.10.024304  

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

Keywords: gst, droplet, instability, vortex, behavior

# gst: emergent flocking in mixtures of antialigning self-propelled particles.

FIG. 4. (c) Mean field phase diagram with disorder (green triangles), polarized moving bands (blue circles), and polarized patches (orange squares).

AA << observe a flocking mechanism, the emergence of a state with global polar order, in mixed systems of self-propelled particles with purely antialigning interactions, i.e., the ground state for any pair of particles is to be opposedly oriented. In binary mixtures, (They) find that flocking can be realized by cross-species antialigning that is dominant compared to intraspecies antialignment. >>

<< While the key mechanism can be understood within a mean-field description, beyond mean-field (AA) develop an asymptotically exact Boltzmann-scattering theory from first principles.  This theory yields analytical predictions for the flocking transition and shows excellent quantitative agreement with simulations of dilute systems. For large systems, (They) find either microphase separation or static patterns with patches or stripes that carry different polarization orientations. >>️

Rüdiger Kürsten, Jakob Mihatsch, Thomas Ihle. Emergent flocking in mixtures of antialigning self-propelled particles. Phys. Rev. E 111, L023402. Feb 21, 2025.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.111.L023402

Also: particle, flock, flocking, swarm, order, disorder, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, particles, self-propelled particles, flock, flocking, swarm, order, disorder, transitions

# gst: 'jazzy' intermittency, its onset and multiscaling in active turbulence.

<< Recent results suggest that highly active, chaotic, nonequilibrium states of living fluids might share much in common with high Reynolds number, inertial turbulence. (AA) now show, by using a hydrodynamical model, the onset of intermittency and the consequent multiscaling of Eulerian and Lagrangian structure functions as a function of the bacterial activity. (Their) results bridge the worlds of low and high Reynolds number flows as well as open up intriguing possibilities of what makes flows intermittent. >>️

AA << believe that (Their) work significantly understands the dynamics of dense bacterial suspensions in ways which isolates the truly turbulent effects from those stemming from simpler chaotic motion. More intriguingly, and at a broader conceptual framework, this study yet again underlines that intermittency can be an emergent phenomena in flows where the nonlinearity does not, trivially, dominate the viscous damping. Indeed, there is increasing evidence of intermittency emerging in systems which are not turbulent in the classical sense. Examples include flows with modest Reynolds number of∼O(10e2) showing intermittent behaviour characteristic of high Reynolds turbulence, self-propelling active droplets with intermittent fluctuations, active matter systems of self-propelled particles, which undergo a glass transition, with an intermittent phase before dynamical arrest, and perhaps most pertinently, in elastic turbulence. Thus, (AA) believe, (Their) work will contribute further to understanding what causes flows to turn intermittent. Answers to such questions will also help in understanding fundamental questions in high Reynolds number turbulence. >>️

Kolluru Venkata Kiran, Kunal Kumar, et al. Onset of Intermittency and Multiscaling in Active Turbulence. Phys. Rev. Lett. 134, 088302. Feb 28, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.088302  arXiv: 2408.06950v2 [cond-mat.soft].  https://arxiv.org/abs/2408.06950

Also: intermittency, transition, fluctuations, drop, droplet, droploid, elastic, turbulence, chaos, jazz, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, intermittency, transitions, fluctuations, drops, droplets, droploids, elasticity, turbulence, chaos, jazz

# gst: transition to inverse cascade in turbulent rotating convection in absence of the large-scale vortex.

<< Turbulent convection under strong rotation can develop an inverse cascade of kinetic energy from smaller to larger scales. In the absence of an effective dissipation mechanism at the large scales, this leads to the pile-up of kinetic energy at the largest available scale, yielding a system-wide large-scale vortex (LSV). Earlier works have shown that the transition into this state is abrupt and discontinuous. >>

Here, AA << study the transition to the inverse cascade in the case where the inverse energy flux is dissipated before it reaches the system scale, suppressing the LSV formation. (They) demonstrate how this can be achieved in direct numerical simulations by using an adapted form of hypoviscosity on the horizontal manifold. (They) find that in the absence of the LSV, the transition to the inverse cascade becomes continuous. This shows that it is the interaction between the LSV and the background turbulence that is responsible for the observed discontinuity. >>

AA << furthermore show that the inverse cascade in absence of the LSV has a more local signature compared to the case with LSV. >>️

Xander M. de Wit. Transition to inverse cascade in turbulent rotating convection in absence of the large-scale vortex. arXiv: 2502.16275v1 [physics.flu-dyn]. Feb 22, 2025. 

https://arxiv.org/abs/2502.16275

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

Keywords: gst, turbulence, dissipation, transitions, vortices

# gst: turbulence-induced fluctuating interfaces in heterogeneously-active suspensions.

AA << investigate the effects of heterogeneous (spatially varying) activity in a hydrodynamical model for dense bacterial suspensions, confining ourselves to experimentally realizable, simple, quenched, activity patterns. (They) show that the evolution of the bacterial velocity field under such activity patterning leads to the emergence of hydrodynamic interfaces separating spatially localized turbulence from jammed frictional surroundings. (They) characterise the intermittent and multiscale fluctuations of this interface and also investigate how heterogeneity influences mixing via the residence times of Lagrangian tracers. >>

This AA work << reveals how naturally occurring heterogeneities could decisively steer active flows into more complex configurations than those typically studied, opening up parallels to droplet dynamics, front propagation and turbulent mixing layers. >>️

Siddhartha Mukherjee, Kunal Kumar, Samriddhi Sankar Ray. Turbulence-Induced Fluctuating Interfaces in Heterogeneously-Active Suspensions. arXiv: 2502.16443v1 [cond-mat.soft]. Feb 23, 2025. 

https://arxiv.org/abs/2502.16443

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

Keywords: gst, fluctuations, vortices, turbulence, turbulent and quiescent flows

# gst: amplification of turbulence through multiple planar shocks.

AA << study the amplification of isotropic, incompressible turbulence through multiple planar, collisional shocks, using analytical linear theory. There are two limiting cases (They) explore. The first assumes shocks occur rapidly in time such that the turbulence does not evolve between shocks. Whereas the second case allows enough time for turbulence to isotropize between each shock. For the latter case, through a quasi-equation-of-state, we show that the weak multi-shock limit is agnostic to the distinction between thermal and vortical turbulent pressures, like an isotropic volumetric compression. >>

<< When turbulence does not return to isotropy between shocks, the generated anisotropy -- itself a function of shock strength -- can feedback on amplification by further shocks, altering choices for maximal or minimal amplification. >>

<< In addition for this case, (AA) find that amplification is sensitive to the shock ordering. (They) map how choices of shock strength can impact these amplification differences due to ordering, finding, for example, shock pairs which lead to identical mean post-shock fields (density, temperature, pressure) but maximally distinct turbulent amplification. >>️

Michael F. Zhang, Seth Davidovits, Nathaniel J. Fisch. Amplification of turbulence through multiple planar shocks. arXiv: 2502.18708v1 [astro-ph.GA]. Feb 25, 2025. 

https://arxiv.org/abs/2502.18708

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

Keywords: gst, waves, turbulence, vortex, shocks 

# game: strategic decision making in biological and artificial brains.

Figure 4: Cooperation rates across different learning scenarios in Agent vs. Agent experiments. 

(a) Constrained learning using cooperation (high initial variability) 

(b) Constrained learning using defection (high initial variability) 

(c) Constrained learning using cooperation (low variability) 

(d) Constrained learning using defection (low variability) 

(e) Unconstrained learning.

(...)

<< The aim of (AA) paper is twofold. First, it seeks to uncover the algorithms that humans and other animals employ for learning in decision-making strategies within non-zero-sum games, specifically focusing on fully observable iterated prisoner’s dilemma scenarios. Second, it aims to develop a new model to explain strategic decision-making which reflects previous neurobiological findings showing that different brain circuits are responsible for self-referential processing and understanding others. The model stems from the actor-critic framework and incorporates multiple critics to allow for distinct processing of both self and others’ state. >>

AA << validate the biological plausibility and transferability of (Their) algorithm through comparisons with experimental data from human on the iterated prisoner’s dilemma game. >>️

Anushka Deshpande. Strategic Decision Making in Biological and Artificial Brains. biorxiv. doi: 10.1101/ 2025.02.17.638746. Feb 24, 2025.

https://www.biorxiv.org/content/10.1101/2025.02.17.638746v1

Also: behav, game, tit-for-tat, brain, in https://www.inkgmr.net/kwrds.html 

Keywords: behavior, games, tit-for-tat, brain 

# gst: apropos of transitions to turbulence, pulsatility delays the transition to sustained turbulence in quasi-2D shear flows

<< Two-dimensional disturbances require high Reynolds numbers to incite transition from a steady base flow, as transient growth is modest. With the addition of an oscillatory base flow component, (AA) work shows that the transient growth experienced by two-dimensional initial perturbations is often well above that provided by the steady component. >>

<< However, as has been shown for three-dimensional flows [B. Pier and P. J. Schmid, J. Fluid Mech. 926, A11 (2021)], the transient growth is almost entirely composed of modal intracyclic growth, rather than a transient mechanism which takes advantage of non-normality. This lack of transient growth, relative to the severe decay induced by the favorable pressure gradient during the acceleration phase of the oscillatory base flow, only ever delays the transition to sustained turbulence. >>

<< Thus, a nonoscillatory driving force remains the most efficient strategy for sustained turbulence in quasi-two-dimensional shear flows. The only benefit provided by pulsatility is that the amplitude of the initial condition required to trigger intermittent turbulence is orders of magnitude smaller. >>️

Christopher J. Camobreco, Alban Pothérat, Gregory J. Sheard. Pulsatility delays the transition to sustained turbulence in quasi-two-dimensional shear flows. Phys. Rev. Fluids 10, 023905. Feb 25, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.10.023905

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

Keywords: gst, pause, transition, turbulence, vortex

# behav: locomotion-dependent auditory gating to the parietal cortex guides multisensory decisions

<< Decision-making in mammals fundamentally relies on integrating multiple sensory inputs, with conflicting information resolved flexibly based on a dominant sensory modality. However, the neural mechanisms underlying state-dependent changes in sensory dominance remain poorly understood. >>

 AA << study demonstrates that locomotion in mice shifts auditory-dominant decisions toward visual dominance during audiovisual conflicts. Using circuit-specific calcium imaging and optogenetic manipulations, (They) found that weakened visual representation in the posterior parietal cortex (PPC) leads to auditory-dominant decisions in stationary mice. >>

<< Prolonged locomotion, however, promotes visual dominance by inhibiting auditory cortical neurons projecting to the PPC (ACPPC). This shift is mediated by secondary motor cortical neurons projecting to the auditory cortex (M2AC), which specifically inhibit ACPPC neurons without affecting auditory cortical projections to the striatum (ACSTR). >>

AA << findings reveal the neural circuit mechanisms underlying auditory gating to the association cortex depending on locomotion states, providing insights into the state-dependent changes in sensory dominance during multisensory decision-making. >>️

Ilsong Choi, Seung-Hee Lee. Locomotion-dependent auditory gating to the parietal cortex guides multisensory decisions. biorxiv. doi: 10.1101/ 2024.02.14.580296. Jan 24, 2025.

https://www.biorxiv.org/content/10.1101/2024.02.14.580296v2

Also: Inchingolo G. Cultural transitions and epidemiology. Proceedings of the 13th Scientific Meeting of the International Epidemiological Association - IEA, Sydney, Australia, Sept 26--29, 1993: 129. Med Hypotheses 1994; 43(4): 201-206. https://pubmed.ncbi.nlm.nih.gov/7838001/     Inchingolo G. Placebo effects via deterministic chaos during traditional dances. Genova, 7 Marzo 1995: abstract. Proceedings of the 6th Congress of the International Association of Biomedical Gerontology - IABG, (Part 1, Oriental Medicine), Makuhari, Japan, August 20-26, 1995. INRCA, Technical Report, Genova, 18 August 1995: 1-26. https://www.inkgmr.net/papers.html 

Also: behav, dance, transition, brain, sound, ethno, in https://www.inkgmr.net/kwrds.html 

Keywords: behavior, dance, transition, brain, sound, ethno

# gst: apropos of the impact of noise, stochastic Kuramoto oscillators with inertia and higher-order interactions.

<< The impact of noise in coupled oscillators with pairwise interactions has been extensively explored. Here, (AA) study stochastic second-order coupled Kuramoto oscillators with higher-order interactions and show that as noise strength increases, the critical points associated with synchronization transitions shift toward higher coupling values. By employing the perturbation analysis, (They) obtain an expression for the forward critical point as a function of inertia and noise strength. Further, for overdamped systems, (AA) show that as noise strength increases, the first-order transition switches to second-order even for higher-order couplings. >>

️

Priyanka Rajwani, Sarika Jalan. Stochastic Kuramoto oscillators with inertia and higher-order interactions. Phys. Rev. E 111, L012202. Jan 13, 2025.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.111.L012202   arXiv: 2407.14874v1 [nlin.AO]. Jul 20, 2024. https://arxiv.org/abs/2407.14874 

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

Keywords: gst, noise, transition, coupled oscillators, synchronization transition

# gst: attraction-enhanced emergence of friction (in colloidal matter)

<< How frictional effects emerge at the microscopic level in particulate materials remains a challenging question, particularly in systems subject to thermal fluctuations due to the transient nature of interparticle contacts. >>

Here, AA << directly relate particle-level frictional arrest to local coordination in an attractive colloidal model system. (They) reveal that the orientational dynamics of particles slows down exponentially with increasing coordination number due to the emergence of frictional interactions, the strength of which can be tuned simply by varying the attraction strength. Using a simple computer simulation model, (they) uncover how the interparticle interactions govern the formation of frictional contacts between particles. >>

AA << results establish quantitative relations between friction, coordination, and interparticle interactions. This is a key step toward using interparticle friction to tune the mechanical properties of particulate materials. >>️

<< Importantly, almost all theoretical and simulation studies on such systems do not account for interparticle friction. Incorporating frictional constraints to rolling and sliding between particles will likely have a pronounced effect on a variety of phenomena studied in attractive colloidal matter such as gel formation, coarsening and failure. >>

️

Berend van der Meer, Taiki Yanagishima, Roel P. A. Dullens. Attraction-Enhanced Emergence of Friction in Colloidal Matter. Phys. Rev. Lett. 134, 078202. Feb 21, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.078202

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

Keywords: gst, particles, colloids, friction, coordination,  interparticle friction, interparticle interactions

# gst: the sleeping bacterium, shedding light on the resuscitation mechanism.

<< The revival mechanism in dormant bacteria is a puzzling and open issue. (AA) propose a model of information diffusion on a regular grid where agents represent bacteria and their mutual interactions implement quorum sensing. Agents may have different metabolic characteristics corresponding to multiple phenotypes. The intra/inter phenotype cooperation is analyzed under different metabolic and productivity conditions. (AA) study the interactions between rapidly reproducing active bacteria and non-reproducing quiescent bacteria (thus) highlight the conditions under which the quiescent bacteria may revive. The occurrence of revival is generally related to a change in environmental conditions. (AA) results support this picture showing that revival can be mediated by the presence of different catalyst bacteria that produce the necessary resources. >>️

Eleonora Alfinito, Matteo Beccaria. The sleeping bacterium: shedding light on the resuscitation mechanism. arXiv: 2501.09366v1 [physics.bio-ph]. Jan 16, 2025.

https://arxiv.org/abs/2501.09366

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

Keywords: gst, pause, sleep, dormant, quiescence, resuscitation, bacterium 

# gst: when homogeneous systems meet dissipation and disorder.

AA << investigate the localization and topological properties of the non-equilibrium steady state (NESS) in a one-dimensional homogeneous system. (Their) results demonstrate that, despite the absence of disorder in the initial system, the NESS can exhibit localization under bond dissipation. >>

<< Conversely, for an initially flat-band system with compactly localized wave functions, the NESS is delocalized. >>

<< Furthermore, (They) find that the initial localization characteristics of the system significantly influence the localization properties of the NESS. Drawing upon the concept of Bose-Einstein condensate broadening in cold-atom experiments, along with experimental data, (AA) systematically characterize the impact of disorder on the localization and topological properties of the NESS. >>

<< The phase diagram reveals that the NESS can be topologically non-trivial even when the initial state is topologically trivial, and that the topological triviality of the initial state weakens the topological non-triviality of the NESS. >>

Xixi Feng, Ao Zhou, et al. When Homogeneous Systems Meet Dissipation and Disorder. arXiv: 2502.11383v1 [cond-mat.dis-nn]. Feb 17, 2025. 

https://arxiv.org/abs/2502.11383

Also: order, disorder, disorder & fluctuations, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, order, disorder, disorder & fluctuations, transitions

# jazz. Got the Feeling. John McLaughlin, Jeff Beck. Live at Avery Fisher Hall, New York. Apr 30, 1975.

0:00​ Django 2002 

11:14​ Scatterbrain 2002 

15:48​ Manic Depression 1998 

23:11​ Power 1975 

28:54​ Early Led Boots/Power, Jam 1975 

37:58​ Diamond Dust, Jam 1975 

43:56​ Got the Feeling 1975 

1:07:49​ Django 1995 

1:15:12​ Cause We've Ended As Lovers 2023 

"Django" 

"Scatterbrain" 

live at the Royal Festival Hall on 14 September 2002. 

Tony Hymas on keyboards, Randy Hope-Taylor on bass, Stephen Barney on drums. Terry Bozzio (2nd drummer) and Aref Durvesh (tabla) joins on Scatterbrain! 

"Django" is a 1954 jazz standard written by John Lewis as a tribute to the Belgian-born jazz guitarist Django Reinhardt. 

    • Django  ​ from Django album by the Modern Jazz Quartet, released in 1956. 

    • Django  ​ from Evolution solo piano album by John Lewis, released in 1999. 

"Scatterbrain" written by Jeff Beck and Max Middleton. 

    • Scatterbrain  ​ originally from 1975 album Blow By Blow. 

"Manic Depression" 

live from Montreux Jazz Festival 1998. 

    • Manic Depression  ​ originally by Jimi Hendrix. 

"Power" 

live at Auditorium Theatre, Milwaukee, Wisconsin on 10 May 1975. 

Jeff Beck - Guitar, John McLaughlin - Guest Guitar, Wilbur Bascomb - Bass, Max Middleton - Keyboards, Bernard "Pretty" Purdie - Drums. 

    • Power  ​ originally by Stanley Clarke. 

"Early Led Boots/Power, Jam" 

"Diamond Dust, Jam" 

live at Reunion Arena, Dallas, Texas 11 June 1975. 

Jeff Beck as guest guitarist with Mahavishnu Orchestra. John McLaughlin: electric guitar, Ralphe Armstrong: electric bass, Stu Goldberg: keyboards, Steve Kindler: violin, Carol Shive: violin, Norma Jean Bell: saxophone, Premik Russel Tubbs: saxophone, Philip Hirschi: cello, Narada Michael Walden: drums. 

    • Led Boots  ​ from 1976 Wired album. 

    • Diamond Dust  ​ from 1975 Blow By Blow album. 

"Got the Feeling" 

live at Avery Fisher Hall, New York 30 April 1975. 

Jeff Beck - Guitar, John McLaughlin - Guest Guitar, Wilbur Bascomb - Bass, Max Middleton - Keyboards, Bernard Purdie - Drums. 

    • Got the Feeling  ​ from 1971 Rough And Ready album. 

"Django" 

Jeff Beck & John McLaughlin on guitars, Tony Hymas on keyboards, Pino Palladino on bass, Mark Mondesir on drums 

    • Django (Instrumental)  ​ from The Promise album by John McLaughlin, released in 1995. 

"Cause We've Ended As Lovers" 

live at Hanover, Germany 10th October 2023 by John McLaughlin Quintet: bassist Etienne Mbappe, drummer Ranjit Barot, pianist Jany McPherson and Gary Husband on keyboards. Written by Stevie Wonder. 

    • Cause We've Ended as Lovers  ​ from 1975 Blow By Blow album. 

    • Cause We've Ended As Lovers  ​ from 1974 Stevie Wonder Presents Syreeta album. 

@chromedreamer. Jul 6, 2024

https://youtu.be/VLjm1ARIhjA

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

Keywords: jazz, music

# gst: order and chaos in systems of coaxial vortex pairs

Fig. B.12: Ex. with 4 interact. vortex pairs

AA << have analyzed interactions between two and three coaxial vortex pairs, classifying their dynamics as either ordered or chaotic based on strengths, initial sizes, and initial horizontal separations.  >>️

They << found that periodic cases are scattered among chaotic ones across different initial configurations. Quasi-periodic leapfrogging typically occurs when the initial distances between the vortex pairs are small and cannot coexist with vortex-pair overtake. When the initial configuration splits into two interacting vortex pairs and a single propagating vortex pair, the two interacting pairs consistently exhibit periodic leapfrogging. For the smallest initial horizontal separations, the system predominantly exhibits chaotic or quasi-periodic motions rather than periodic leapfrogging with a single frequency. This behavior is due to the strong coupling between all three vortex pairs. When the pairs are in close proximity, more complex and chaotic dynamics emerge instead of periodic motion. >>

Their << findings indicate that quasi-periodic leapfrogging and chaotic interactions generally occur when the three vortex pairs have similar strengths and initial sizes. Conversely, discrepancies in these parameters cause the system to disintegrate into two subsystems: a single propagating vortex pair and two periodically leapfrogging pairs. >>️

️

Christiana Mavroyiakoumou, Wenzheng Shi. Order and Chaos in Systems of Coaxial Vortex Pairs. arXiv: 2502.07002v1 [physics.flu-dyn]. Feb 10, 2025. ️

https://arxiv.org/abs/2502.07002

Also: chaos, vortex, order, disorder, disorder & fluctuations, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, chaos, vortex, order, disorder, disorder & fluctuations

# gst: apropos of nuanced dependencies in intricately coupled network, attractive-repulsive challenge in swarmalators with time-dependent speed.

AA << examine a network of entities whose internal and external dynamics are intricately coupled, modeled through the concept of ``swarmalators'' as introduced by O'Keeffe et al. (Nat. Commun., 8(1):1–13, 2017). (They) investigate how the entities' natural velocities impact the network's collective dynamics and path to synchronization. >>

<< Specifically, (AA) analyze two scenarios: one in which each entity has an individual natural velocity, and another where a group velocity is defined by the average of all velocities. >> 

Their << findings reveal two distinct forms of phase synchronization -- static and rotational -- each preceded by a complex state of attractive-repulsive interactions between entities. This interaction phase, which depends sensitively on initial conditions, allows for selective modulation within the network. By adjusting initial parameters, (AA) can isolate specific entities to experience attractive-repulsive interactions distinct from the group, prior to the onset of full synchronization. >>

<< This nuanced dependency on initial conditions offers valuable insights into the role of natural velocities in tuning synchronization behavior within coupled dynamic networks. >>️

Steve J. Kongni, Thierry Njougouo, et al. Attractive-repulsive challenge in swarmalators with time-dependent speed. arXiv: 2501.06048v1 [nlin.AO]. Jan 10, 2025. 

https://arxiv.org/abs/2501.06048

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

Keywords: gst, swarm, swarmalators, network

# gst: friction-induced bubble edge curvature in flowing 2D confined foams

AA << investigate the flow of quasi-2D liquid foams, composed of a single monolayer of bubbles in close contact and confined between two glass plates in a Hele-Shaw cell, with a specific emphasis on understanding how bubble shapes evolve in response to varying flow speeds. Utilizing an experimental setup capable of displacing a substantial number of bubbles in the spanwise direction, while the bubble shapes remain stationary as the bubbles themselves are advected in a plug flow, (They) reveal an average bubble anisotropy characterized by elongated bubbles in the streamwise direction and curved bubble edges in a preferential orientation. >>

<< Notably, these effects intensify with increasing flow speeds. While the bubble anisotropy is created at the entrance of the cell, (AA) study establishes a clear connection between bubble edge curvature and orientation, confinement thickness, frictional forces with the plates, and the inherent anisotropy of the bubbles. >>

Christophe Raufaste, Lauren Rose, et al. Friction-induced bubble edge curvature in flowing two-dimensional confined foams. Phys. Rev. Fluids 10, 023301. Feb 5, 2025. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.10.023301 

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

Keywords: gst, bubble, foam, friction, surface tension

# gst: alignment-induced self-organization of autonomously steering microswimmers: turbulence, clusters, vortices, and jets.

<< Microorganisms can sense their environment and adapt their movement accordingly, which gives rise to a multitude of collective phenomena, including active turbulence and bioconvection. In fluid environments, collective self-organization is governed by hydrodynamic interactions. >>

<< By large-scale mesoscale hydrodynamics simulations, (AA) study the collective motion of polar microswimmers, which align their propulsion direction by hydrodynamic steering with that of their neighbors. The simulations of the employed squirmer model reveal a distinct dependence on the type of microswimmer—puller or pusher—flow field. No global polar alignment emerges in both cases. Instead, the collective motion of pushers is characterized by active turbulence, with nearly homogeneous density and a Gaussian velocity distribution; strong self-steering enhances the local coherent movement of microswimmers and leads to local fluid-flow speeds much larger than the individual swim speed. >>

<< Pullers exhibit a strong tendency for clustering and display velocity and vorticity distributions with fat exponential tails; their dynamics is chaotic, with a temporal appearance of vortex rings and fluid jets. >>

AA << results show that the collective behavior of autonomously steering microswimmers displays a rich variety of dynamic self-organized structures. >>

Segun Goh, Elmar Westphal, et al. Alignment-induced self-organization of autonomously steering microswimmers: Turbulence, clusters, vortices, and jets. Phys. Rev. Research 7, 013142. Feb 7, 2025. 

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.7.013142 

Also: swim, microswimmer, particle, turbulence, chaos, noise, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, swim, swimmer, microswimmers, particle, turbulence, chaos, noise

# gst: route from avalanches with random fields to stochastic branching events

<< Many complex systems with discrete symmetry breaking exhibit avalanche dynamics. Under quasistatically slow external driving, the temporal evolution v(t) of physical observables appears to be split between long periods of quiescence and well-delimited fast transformation events, the so-called avalanches. >>

<< Due to their fast nature, such avalanches can be regarded as instantaneous and labeled as point events k in time with a branching parameter. (..) Many physical systems exhibit criticality in the form of scale-free avalanches rendering power-law distributions of sizes and durations. >>️

<< Avalanches in mean-field models can be mapped to memoryless branching processes defining a universality class. (AA) present a reduced expression mapping a broad family of critical and subcriticial avalanches in mean-field models at the thermodynamic limit to rooted trees in a memoryless Poisson branching processes with random occurrence times. (They) derive the exact mapping for the athermal random field Ising model and the democratic fiber bundle model, where avalanche statistics progress towards criticality, and as an approximation for the self-organized criticality in slip mean-field theory. Avalanche dynamics and statistics in the three models differ only on the evolution of the field density, interaction strength, and the product of both terms determining the branching number. >>

️

Jordi Baró, Álvaro Corral. A universal route from avalanches in mean-field models with random fields to stochastic Poisson branching events. arXiv: 2502.08526v3 [cond-mat.dis-nn]. Feb 15, 2025. 

https://arxiv.org/abs/2502.08526

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

Keywords: gst, waves, instability, transition

# gst: intrinsic disorder bars intruders (from biomolecular condensates)

<< It was recently discovered that eukaryotic cells are host to a multiplicity of biomolecular condensates. These condensates typically contain protein and/or RNA components with intrinsically disordered regions (IDRs). While IDRs have been proposed and demonstrated to play many roles in condensate biology, (AA) suggest here an additional crucial role of IDRs, which is to exclude unwanted “intruders” from condensates. This exclusion effect arises from the large conformational entropy of IDRs; i.e., there is a high free-energy cost to occupying space that would otherwise be available to the IDRs. By combining polymer theory with sticker-spacer simulations, (They) show that the relevant insertion free energy increases with the concentration of IDRs in the condensate as well as with intruder size, attaining a linear scaling with surface area for large intruders. >>

AA << find that at realistic IDR concentrations, particles as small as the size of an average protein (4 nm in diameter) can be 97% excluded from condensates. To overcome this entropic barrier, molecules must interact favorably with condensate components to be recruited as clients. Application of the developed size-exclusion theory to biological condensates suggests that condensate IDRs may play a generic exclusionary role across organisms and types of condensates. >>️

Vladimir Grigorev, Ned S. Wingreen, Yaojun Zhang. Conformational Entropy of Intrinsically Disordered Proteins Bars Intruders from Biomolecular Condensates. PRX Life 3, 013011. Feb 14, 2025.

https://journals.aps.org/prxlife/abstract/10.1103/PRXLife.3.013011

Also: order, disorder, disorder & fluctuations, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, order, disorder, disorder & fluctuations, transitions

# life: oops! It would appear that Mr. Donald intends to open hunt for Academics as well ... maybe these people are penniless immigrants too?

<< A prominent US scientific society altered its website to remove references to diversity and equity ― terms targeted by the administration of US President Donald Trump. Articles about scientists who are members of under-represented groups also temporarily vanished from the site, although they have since reappeared. >>

<< In an e-mail, ASM (Am Soc for Microbiol) president Theresa Koehler told Nature that the organization had followed legal advice to review all of its webpages, in the hope of protecting its federally funded programmes. >>️

Humberto Basilio. ‘We are a target’: scientific society under pressure after Trump DEI crackdown. Nature. doi: 10.1038/ d41586-025-00372-0. Feb 7, 2025. 

https://www.nature.com/articles/d41586-025-00372-0

Also: A new exception within the FDA Cures Act Informed Consent, the intriguing concept of 'Minimal Risk Clinical Investigations'. FonT. Feb 1, 2024. 

https://flashontrack.blogspot.com/2024/02/life-new-exception-within-fda-cures-act.html 

Also: ️<< You should never be comfortable, man. Being comfortable fouled up a lot of musicians. >> Miles Davis. https://www.azquotes.com/quote/527910 

https://x.com/SVG__Collection/status/1886745080066695455

Also: oops, Mr. Donald, forms of power, virus, sars* covid* (aka 1or2achoos), dance, are you ready for all this, in https://www.inkgmr.net/kwrds.html 

Keywords: life, oops, Mr. Donald, forms of power, acad, virus, sars, covid, 1or2achoos, dance, are you ready for all this

# gst: rise and fall of a multicomponent droplet in a surrounding fluid along a bumpy path.

<< The coupling between mass transfer and hydrodynamic phenomena in two-phase flow is not straightforward due to the different effects that can be encountered. >>

Here, AA << consider the case of a two-component droplet (one miscible and one immiscible in water) released in a 2D rectangular domain filled with water. Mass transfer occurs between the miscible element and the surrounding water, which leads to a density inversion that directly affects the droplet trajectory through buoyancy. >>

Mirantsoa Aime Rasolofomanana, Romain Le Tellier, Herve Henry. Rise and fall of a multicomponent droplet in a surrounding fluid: Simulation study of a bumpy path. Phys. Rev. Fluids 10, 023601. Feb 5, 2025. 

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.10.023601 

<< the coupling between the flow and the diffusion leads to a significant increase in the magnitude of the upward motion of the droplet before it starts to fall. >>️

arXiv: 2403.20040v2 [physics.flu-dyn]. Dec 18, 2024. 

https://arxiv.org/abs/2403.20040

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

Keywords: gst, drop, droplet, droploid 

# gst: necklacelike pattern of vortex bound states

<< A vortex is a topological defect in the superconducting condensate when a magnetic field is applied to a type-II superconductor, (..). Because of the confinement of the quasiparticles by a vortex, it exhibits a circular-shaped pattern of bound states with discrete energy levels, (..) >>

 Here, AA << report a completely new type of vortex pattern which is necklacelike in an iron-based superconductor (..). (AA) theoretical analysis shows that this necklacelike vortex pattern arises primarily from selective off-shell interference between vortex bound states of opposite angular momenta in the presence of rotational symmetry breaking due to disorders. >>

<< This fascinating effect can be observed in a system with a small Fermi energy and wave vector, conditions fortuitously met in (Their) samples. (AA) results not only disclose a novel vortex structure, but also unravel a completely new quantum phenomenon in the superconducting condensate. >>️

Zhiyong Hou, Kailun Chen, et al. Necklacelike Pattern of Vortex Bound States. Phys. Rev. X 15, 011027. Feb 7, 2025.   https://journals.aps.org/prx/abstract/10.1103/PhysRevX.15.011027   arXiv: 2407.08547v1 [cond-mat.supr-con]. Jul 11, 2024.    https://arxiv.org/abs/2407.08547

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

Keywords: gst, vortex, vortex bound states, symmetry breaking, disorder, disorder & fluctuations, necklacelike patterns

# gst: chaotic billiards inside mixed curvatures

<< The boundary of a billiard system dictates its dynamics, which can be integrable, mixed, or fully chaotic. >>️

This AA study << introduces two such billiards: a bean-shaped billiard and a peanut-shaped billiard, the latter being a variant of Cassini ovals. Unlike traditional chaotic billiards, these systems incorporate both focusing and defocusing regions along their boundaries, with no neutral segments. >>

AA << examine both classical and quantum dynamics of these billiards and observe a strong alignment between the two perspectives. For classical analysis, the billiard flow diagram and billiard map reveal sensitivity to initial conditions, a hallmark of classical chaos. In the quantum domain, (AA) use nearest-neighbour spacing distribution and spectral complexity as statistical measures to characterise chaotic behaviour. >>

<< Both classical and quantum mechanical analysis are in firm agreement with each other. One of the most striking quantum phenomena (They) observe is the eigenfunction scarring (both scars and super-scars). Scarring phenomena serve as a rich visual manifestation of quantum and classical correspondence, and highlight quantum suppression chaos at a local level. >>

Pranaya Pratik Das, Tanmayee Patra, Biplab Ganguli. Manifestations of chaos in billiards: the role of mixed curvature. arXiv: 2501.08839v1 [nlin.CD]. Jan 15, 2025.

https://arxiv.org/abs/2501.08839

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

Keywords: gst, billiard, chaos

# gst: apropos of subdiffusive behaviors, the boomerang effect in classical stochastic models.

<< The phenomenon of Anderson localization, occurring in a disordered medium, significantly influences the dynamics of quantum particles. A fascinating manifestation of this is the “quantum boomerang effect” (QBE), observed when a quantum particle, propelled with a finite initial velocity, reverses its average trajectory, eventually halting at its starting point. >>

AA << uncover evidence of a similar effect in classical systems, characterized by the absence of typical diffusion processes. (Their) investigation encompasses both simplified probabilistic models and more complex phenomenological models that link classical with quantum mechanics. The results indicate that the boomerang effect is not confined to the quantum realm and may also be present in diverse systems exhibiting subdiffusive behavior. >>️

Santiago Zamora, Lisan M. M. Durao, et al. Boomerang effect in classical stochastic models. Phys. Rev. E 111, 024104. Feb 3, 2025.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.111.024104 

Also: behav, particle, disorder, disorder & fluctuations, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, behavior, particles, disorder, disorder & fluctuations, stocasticity, boomerang effect