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Visualizzazione post con etichetta transitions. Mostra tutti i post
Visualizzazione post con etichetta transitions. Mostra tutti i post

venerdì 20 febbraio 2026

# gst: defect states as a precursor of the chimera states in a ring of non-locally coupled oscillators.


<< ️(AA) investigate the transition from synchronized to chimera states in a ring of non-locally coupled phase oscillators. (Their) focus is on the intermediate defect states, where solitary waves in the phase gradient profile travel at a constant speed. These traveling defects serve as a dynamical precursor for the nucleation of chimera clusters. The fraction of samples exhibiting defect states increases with the phase delay α and peaks at α_c, where the system crosses over to asynchronous states filled with chimera clusters. While the traveling speed, number, and width of these defects increase with α, the total spatial extent of the defects remains robust against the system size N. >> 

Tianjing Zhou, Nariya Uchida. Defect states as a precursor of the chimera states in a ring of non-locally coupled oscillators. arXiv: 2602.10533v1 [nlin.AO]. Feb 11, 2026.

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

Keywords: gst, transitions, chimera, chimera clusters, coupled phase oscillators, intermediate defect states, solitary waves, asynchronous states. 

giovedì 19 febbraio 2026

# gst: elastoplastic modelling of cyclic shear deformation of amorphous solids.

IMG - Per site elastic energy evolution for poorly vs well annealed samples.

<< ️(AA) develop an energy-landscape based elasto-plastic model to understand the behaviour of amorphous solids under uniform and cyclic shear. Amorphous solids are modeled as being composed of mesoscopic sub-volumes, each of which may occupy states - termed mesostates -- drawn from a specified distribution. The energies of the mesostates under stress free conditions determine their stability range with respect to applied strain, and their plastic strain, at which they are stress free, forms an important additional property. Under applied global strain, mesostates that reach their stability limits transition to other permissible mesostates. Barring such transitions, which encompass plastic deformations that the solid may undergo, mesostates are treated as exhibiting linear elastic behavior, and the interactions between mesoscopic blocks are treated using the finite element method.  >>

<< ️The (AA) model reproduces known phenomena under uniform and cyclic shear, such as the brittle-to-ductile crossover with annealing and the Bauschinger effect for uniform shear, qualitative features of the yielding diagram under cyclic shear including the change in yielding behaviour with the degree of annealing, across a `threshold level', and dynamic phenomena such as the divergence of failure times on approach to the yield point and the non-monotonic evolution of the local yield rate.  >>

<< ️In addition to these results, (They) discuss the dependence of the observed behaviour on model choices, and open questions highlighted by (Their) work. >>

Pushkar Khandare, Srikanth Sastry. Elastoplastic Modelling of Cyclic Shear Deformation of Amorphous Solids. arXiv: 2602.06174v2 [cond-mat.soft]. Feb 5,  2026.

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

Keywords: gst, transitions, amorphous solids, cyclic shear, mesostates, mesoscopic sub-volumes, plastic strain, plastic deformation, linear elastic behavior, stability limits transition, brittle-to-ductile crossover, divergence of failure times.

lunedì 16 febbraio 2026

# life: the role played by women in shaping human evolution.

<< ️(AA) have used ancient DNA to reveal that hunter-gatherers in one part of Europe survived for thousands of years longer than anywhere else on the continent—and have uncovered the pivotal role of women in the process >>

<< ️Ancient DNA studies often bring to light unexpected pages of our past. We might anticipate finding the unexpected when analyzing samples from unexplored or peripheral regions of the globe. But here we are looking at the heartland of Europe, making these results even more striking. It's a testament to the power of ancient DNA studies that findings like these can still surprise us. This study has also brought to light the crucial role played by women in the transmission of knowledge from the incoming farming communities to the local hunter-gatherers. Thanks to ancient DNA studies, we can not only uncover the past but also give voice to the invaluable but often overlooked role played by women in shaping human evolution. >> Maria Pala. 

Gaby Clark, Robert Egan. Ancient DNA suggests hunter-gatherers in Europe's lowlands endured until 2500 BCE. University of Huddersfield. http://www.hud.ac.uk  Feb 11, 2026.

Olalde, I., Altena, E., Bourgeois, Q. et al. Lasting Lower Rhine–Meuse forager ancestry shaped Bell Beaker expansion. Nature (2026). https://doi.org/10.1038/s41586-026-10111-8

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

Keywords: Nomads, transitions, life

sabato 7 febbraio 2026

# gst: fractals in rate-induced tipping.

<< ️When parameters of a dynamical system change sufficiently fast, critical transitions can take place even in the absence of bifurcations. This phenomenon is known as rate-induced tipping and has been reported in a variety of systems, from simple ordinary differential equations and maps to mathematical models in climate sciences and ecology. In most examples, the transition happens at a critical rate of parameter change, a rate-induced tipping point, and is associated with a simple unstable orbit (edge state). >>

<< ️In this work, (AA) show how this simple picture changes when non-attracting fractal sets exist in the autonomous system, a ubiquitous situation in non-linear dynamics. (They) show that these fractals in phase space induce fractals in parameter space, which control the rates and parameter changes that result in tipping. (They) explain how such rate-induced fractals appear and how the fractal dimensions of the different sets are related to each other. >>

<< ️(AA) illustrate (Their) general theory in three paradigmatic systems: a piecewise linear one-dimensional map, the two-dimensional Hénon map, and a forced pendulum. >>

Jason Qianchuan Wang, Yi Zheng, Eduardo G. Altmann. Fractals in rate-induced tipping. arXiv: 2601.16373v1 [nlin.CD]. Jan 23, 2026.

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

Keywords: gst, transitions, pendulum, forced pendulum, fractals, absence of bifurcations, rate-induced tipping, criticality.

venerdì 6 febbraio 2026

# gst: directionality and node heterogeneity reshape criticality in hypergraph percolation.


<< Directed and heterogeneous hypergraphs capture directional higher-order interactions with intrinsically asymmetric functional dependencies among nodes. As a result, damage to certain nodes can suppress entire hyperedges, whereas failure of others only weakens interactions. Metabolic reaction networks offer an intuitive example of such asymmetric dependencies. >>

<< Here (AA) develop a message-passing and statistical mechanics framework for percolation in directed hypergraphs that explicitly incorporates directionality and node heterogeneity. Remarkably, (They)  show that these hypergraph features have a fundamental effect on the critical properties of hypergraph percolation, reshaping criticality in a way that depends on network structure. >>

<< Specifically, (AA) derive anomalous critical exponents that depend on whether node or hyperedge percolation is considered in maximally correlated, heavy-tailed regimes. These theoretical predictions are validated on synthetic hypergraph models and on a real directed metabolic network, opening new perspectives for the characterization of the robustness and resilience of real-world directed, heterogeneous higher-order networks. >>

Yunxue Sun, Xueming Liu, Ginestra Bianconi. Directionality and node heterogeneity reshape criticality in hypergraph percolation. arXiv: 2601.20726v1 [cond-mat.dis-nn]. Jan 28, 2026.

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

Keywords: gst, networks, transitions, criticality, hypergraph, percolation, anchor nodes.

martedì 3 febbraio 2026

# gst: nonlocal Kramers-Moyal formulas and data-driven discovery of stochastic dynamical systems with multiplicative Lévy noise.

<< ️Traditional data-driven methods, effective for deterministic systems or stochastic differential equations (SDEs) with Gaussian noise, fail to handle the discontinuous sample paths and heavy-tailed fluctuations characteristic of Lévy processes, particularly when the noise is state-dependent. >>

<< ️To bridge this gap, (AA) establish nonlocal Kramers-Moyal formulas, rigorously generalizing the classical Kramers-Moyal relations to SDEs with multiplicative Lévy noise. These formulas provide a direct link between short-time transition probability densities (or sample path statistics) and the underlying SDE coefficients: the drift vector, diffusion matrix, Lévy jump measure kernel, and Lévy noise intensity functions. >>

<< This (AA) work provides a principled and practical toolbox for discovering interpretable SDE models governing complex systems influenced by discontinuous, heavy-tailed, state-dependent fluctuations, with broad applicability in climate science, neuroscience, epidemiology, finance, and biological physics. >>

Yang Li, Jinqiao Duan. Nonlocal Kramers-Moyal formulas and data-driven discovery of stochastic dynamical systems with multiplicative Lévy noise. arXiv: 2601.19223v1 [math.DS]. Jan 27, 2026.

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

Keywords: gst, noise, randomness, transitions, fluctuations.

sabato 31 gennaio 2026

# gst: time-delayed dynamics in regular Kuramoto networks with inertia: multistability, traveling waves, chimera states, and transitions to seizure-like activity.

<< ️This (AA) study examines the complex interplay between inertia and time delay in regular rotor networks within the framework of the second-order Kuramoto model. By combining analytical and numerical methods, (AA) demonstrate that intrinsic time delays -- arising from finite information transmission speeds - induce multistability among fully synchronized phase-locked states. >>

<< ️Unlike systems without inertia, the presence of inertia destabilizes these phase-locked states, reduces their basin of attraction, and gives rise to nonlinear phase-locked dynamics over specific inertia ranges. >>

<< ️In addition, (They) show that time delays promote the emergence of turbulent chimera states, while inertia enhances their spatial extent. Notably, the combined influence of inertia and time delay produces dynamic patterns reminiscent of partial epileptic seizures. >>

Esmaeil Mahdavi, Mina Zarei, Philipp Hövel, Farhad Shahbazi. Time-Delayed Dynamics in Regular Kuramoto Networks with Inertia: Multistability, Traveling Waves, Chimera States, and Transitions to Seizure-Like Activity.  arXiv: 2512.16640v1 [nlin.AO]. Dec 18, 2025.

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

Keywords: gst, networks, transitions, waves, chimera, turbulence, inertia, time delay, multistability, epileptic seizures.

venerdì 23 gennaio 2026

# gst: generation of disordered networks with targeted structural properties.

<< ️Disordered spatial networks are model systems that describe structures and interactions across multiple length scales. Scattering and interference of waves in these networks can give rise to structural phase transitions, localization, diffusion, and band gaps. >>

<< ️(AA) tune the degree and type of disorder introduced into initially crystalline networks by varying the bond-bending force constant in the strain energy and the temperature profile. >>

<< ️As a case study, (AA) statistically reproduce four disordered biophotonic networks exhibiting structural color. This work presents a versatile method for generating disordered networks with tailored structural properties. It will enable new insights into structure-property relations, such as photonic band gaps in disordered networks. >>

Florin Hemmann, Vincent Glauser, Ullrich Steiner, Matthias Saba. Computer Generation of Disordered Networks with Targeted Structural Properties. arXiv: 2601.10333v1 [cond-mat.dis-nn]. Jan 15, 2026.

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

Keywords: gst, networks, disorder, disordered networks, waves, phase transitions.

lunedì 19 gennaio 2026

# gst: wrinkling dynamics accelerate due to sudden changes in boundary conditions.

<< ️(AA) investigate the wrinkling dynamics of a long, flat filament immersed in a viscous fluid subjected to compression at a constant rate. Typical wrinkling dynamics proceed through three stages: initiation, development, and relaxation. The first stage, during which high mode perturbations increase exponentially while the shape and filament tension remain almost unchanged, is notably longer in the linear and nonlinear simulations than in the experiments by Chopin et al. [Phys. Rev. Lett. 119, 088001 (2017)]. >>

<< ️(AA) propose that sudden environmental changes introduce extra high-frequency perturbations beyond thermal fluctuations, which significantly accelerates the first stage. This effect is universal and inevitable for similar processes given the experimental conditions. >>

<< ️Finally, (They) analyze the relationship between the initial perturbations and the duration of the first stage. >>

Kai Liu, Wang Xiao, John Lowengrub, et al. Wrinkling dynamics accelerate due to sudden changes in boundary conditions. Phys. Rev. E 113, 015102. Jan 13, 2026.

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

Keywords: gst, transitions, wrinkling

giovedì 15 gennaio 2026

# gst: chimera states in wheel networks

<< ️How higher-order interactions influence dynamical behavior in networks of coupled chaotic oscillators remains an open question. To address this, (AA) investigate emergent dynamical behaviors in a wheel network of Rössler and Lorenz oscillators that incorporates both pairwise (1-simplex) and higher-order (2-simplex) interactions under three coupling schemes, namely, diffusive, conjugate, and mean-field diffusive coupling. >>

<< ️(AA) numerical analysis reveals four distinct collective behaviors: synchronization, desynchronization, chimera states, and synchronized clusters. To systematically classify these dynamical behaviors, (They) introduce two statistical measures that effectively capture synchronization patterns among arbitrarily positioned nodes. Applying these measures across all dynamical models and coupling schemes (six different models in total), (They) show that both pairwise and higher-order interactions crucially influence the emergence and robustness of chimera states. (They) observe that under pairwise interaction alone, chimera states appear with high prevalence in specific coupling ranges, though the robustness depends on both the coupling scheme and the underlying dynamical system. >>

<< Incorporation of higher-order interactions reveals that the higher-order interaction underlying diffusive coupling enhances chimera states in both Rössler and Lorenz networks; under conjugate coupling, it strengthens chimera states in Lorenz but instead promotes full synchronization in Rössler; and under mean-field diffusive coupling, higher-order interactions generally favor synchronization, particularly for Rössler oscillators, but promote chimera in the Lorenz system for the intermediate range of its strengths. >>

<< ️Overall, (AA) results demonstrate that higher-order interactions can significantly modulate, promote, or suppress chimera states depending on the coupling mechanism and oscillator dynamics. >>

Ashwathi Poolamanna, Medha Bhindwar, Chandrakala Meena. Chimera States in Wheel Networks. arXiv: 2601.01411v1 [nlin.CD]. Jan 4, 2026.

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

Keywords: gst, chimera, network, transitions

sabato 3 gennaio 2026

# gst: settling dynamics of an oloid, experiments and simulations.


<< ️This (AA) study presents a combined experimental and computational investigation of an oloid shaped particle settling in a quiescent fluid. The oloid, a unique convex shape with anisotropic geometry, provides a distinctive model for exploring how a particle's shape and orientation affect its settling dynamics. >>

<< ️(AA) results indicate two distinct falling modes for the oloid, separated by Galileo number. The stable mode is characterised by a preferential orientation, with a rotation around the vertical axis, whereas the tumbling mode has randomly distributed orientation and rotation statistics. (They) characterise the falling velocity, orientation, and rotation dynamics of the oloids over a range of Galileo numbers. Additionally, the influence of the initial orientation is revealed to determine the rotation dynamics at low Galileo numbers. >>

Mees M. Flapper, Giulia Piumini, Roberto Verzicco, et al. Settling dynamics of an oloid: experiments and simulations. arXiv: 2511.05137v1 [physics.flu-dyn]. Nov 7, 2025.

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

Keywords: gst, particle, transitions, oloids, oloid shaped particles, multiple falling regimes, falling mode, tumbling mode.

lunedì 29 dicembre 2025

# gst: compressed self-avoiding walks in two and three dimensions.


<< ️(AA) consider the phase transition induced by compressing a self-avoiding walk in a slab where the walk is attached to both walls of the slab in two and three dimensions, and the resulting phase once the polymer is compressed. The process of moving between a stretched situation where the walls pull apart to a compressed scenario is a phase transition with some similarities to that induced by pulling and pushing the end of the polymer. >>

<< ️However, there are key differences in that the compressed state is expected to behave like a lower dimensional system, which is not the case when the force pushes only on the end point of the polymer. (They) use scaling arguments to predict the exponents both associated with the phase transition and in the compressed state and find good agreement with Monte Carlo simulations. >>

C. J. Bradly, N. R. Beaton, A. L. Owczarek. Compressed self-avoiding walks in two and three dimensions. Phys. Rev. E 112, 054126. Nov 17, 2025.

arXiv: 2506.11433v2 [cond-mat.stat-mech]. Oct 23, 2025.

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

Keywords: gst, transitions, phase transitions, self-avoiding walk, criticality, polymer conformation, topology.

sabato 27 dicembre 2025

# gst: apropos of reversibility, dynamics of reversible plasticity in an amorphous solid.


<< ️Local rearrangements are the elements of plastic deformation in an amorphous solid. In oscillatory shear, they can switch reversibly between two distinct configurations. While these repeating relaxations are typically considered in the limit of slow driving, their dynamics is less well understood. >>

<< ️(AA) perform experiments on a colloidal amorphous solid at an oil-water interface. The rearrangement timescales we observe span at least 1 decade, with no apparent upper bound. As frequency is increased, individual rearrangements appear faster and more hysteretic, but may disappear entirely above a crossover frequency -- suggesting that in practical experiments, the slowest rearrangements may be latent. (They) show how to find the effective potential energy that reproduces a particle's frequency-dependent motion. In rare cases, this potential energy has only one minimum. >>

Zhicheng Wang, Nathan C. Keim. Dynamics of Reversible Plasticity in an Amorphous Solid. arXiv: 2512.17816v1 [cond-mat.soft]. Dec 19, 2025.

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

Keywords: gst, colloids, colloidal amorphous solids, repulsive particles, reversible plasticity, plastic rearrangements, oscillatory shear, bistable rearrangements, repeating relaxations, transitions, logarithmic aging, silly putty dynamics.

sabato 20 dicembre 2025

# evol: fluctuating environments favor extreme dormancy strategies and penalize intermediate ones.


<< ️Dormancy is a widespread adaptive strategy that enables populations to persist in fluctuating environments, yet how its benefits depend on the temporal structure of environmental variability remains unclear. (AA) examine how dormancy interacts with environmental correlation times using a delayed-logistic model in which dormant individuals reactivate after a fixed lag while birth rates fluctuate under temporally correlated stochasticity. >> 

<< ️Numerical simulations and analytical calculations show that the combination of demographic memory and colored multiplicative noise generates a strongly non-monotonic dependence of fitness on dormancy duration, with three distinct performance regimes. Very short dormancy maximizes linear growth but amplifies fluctuations and extinction risk. Very long dormancy buffers environmental variability, greatly increasing mean extinction times despite slower growth. Strikingly, (They) find a broad band of intermediate dormancy durations that is maladaptive, simultaneously reducing both growth and persistence due to a mismatch between delay times and environmental autocorrelation. >>

<< ️An evolutionary agent-based model confirms bistability between short- and long-dormancy strategies, which avoid intermediate lag times and evolve toward stable extremes. >>

<< ️These (AA) results show that dormancy duration is not merely a life-history parameter but an adaptive mechanism tuned to environmental timescales, and that intermediate "dangerous middle" strategies can be inherently disfavored. More broadly, this work identifies a generic mechanism by which demographic delays interacting with correlated environmental variability produce a non-monotonic fitness landscape that selects for extreme timing strategies. >>

Jorge Hidalgo, Lorenzo Fant, Rafael Rubio de Casas, Miguel A. Muñoz. Fluctuating Environments Favor Extreme Dormancy Strategies and Penalize Intermediate Ones. arXiv: 2512.05856v1 [q-bio.PE]. Dec 5, 2025.

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

Keywords: evolution, adaptation, transition, dormancy, fluctuating environments, stochasticity, noise.

mercoledì 17 dicembre 2025

# gst: instability triggered by mixed convection in a thin fluid layer.


<< ️(AA) investigate the convective stability of a thin, infinite fluid layer with a rectangular cross-section, subject to imposed heat fluxes at the top and bottom and fixed temperature along the vertical sides. The instability threshold depends on the Prandtl number as well as the normalized flux difference (f) and decreases with the aspect ratio (ϵ), following a ϵf^−1 power law. >>

<< ️Using 3D initial value and 2D eigenvalue calculations, (They) identify a dominant 3D mode characterized by two transverse standing waves attached to the domain edges. (They) characterize the dominant mode’s frequency and transverse wave number as functions of the Rayleigh number and aspect ratio. An analytical asymptotic solution for the base state in the bulk is obtained, valid over most of the domain and increasingly accurate for lower aspect ratios. >>

<< A local stability analysis, based on the analytical base state, reveals oscillatory transverse instabilities consistent with the global instability characteristics. The source term for this most unstable mode appears to be interactions between vertical shear and horizontal temperature gradients. >>

Florian Rein, Keaton J. Burns, Stefan G. Llewellyn Smith, et al. Instability triggered by mixed convection in a thin fluid layer. arXiv: 2512.02331v1 [physics.flu-dyn]. Dec 2, 2025.

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

Keywords: gst, waves, instability, transitions, convection, vertical shear, horizontal temperature gradients.

martedì 16 dicembre 2025

# gst: two instabilities in one liquid sheet.


<< ️Two cylindrical liquid jets (dia = 1 mm) of a glycerol-water mixture (80/20) impinge at 90º to one another, creating a thin liquid sheet bordered by a thick rim. Classical fish-bone shapes (sheet-thread-droplet) are formed where the rim instability is driven by Rayleigh-Plateau type mechanisms. >>

<< ️Here (AA) also see fish-bone shapes occurring for similar reasons. However, the waves on the sheet are formed by small imbalances between the two jet velocities (natural pipe driven oscillation), rather than the traditional Kelvin-Helmholtz instability. (They) stroboscopic photograph of the sheet reveals that both of these instabilities can coexist within a narrow range of operating conditions. >>

<< ️The breakup of the liquid sheet (lower down) is caused by the combined instability of spatially growing waves. The liquid sheet breaks down mainly through the growth of bounded waves. These waves eventually break, forming long threads at the bottom of the sheet, which further disintegrate into droplets due to the Rayleigh-Plateau instability of threads. >>

Sandip Dighe, Hrishikesh Gadgil, Tadd Truscott. Two instabilities in one liquid sheet. Phys. Rev. Fluids 10, 110501. Nov 20, 2025

77th Annual Meeting of the APS Division of Fluid Dynamics (Nov 24 — 26, 2024). P2692828: Two instabilities in one liquid

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

Keywords: gst, waves, instability, transitions.

domenica 14 dicembre 2025

# gst: symmetries at the origin of hierarchical emergence.

<< ️Many systems of interest exhibit nested emergent layers with their own rules and regularities, and our knowledge about them seems naturally organised around these levels. This (AA) paper proposes that this type of hierarchical emergence arises as a result of underlying symmetries. By combining principles from information theory, group theory, and statistical mechanics, one finds that dynamical processes that are equivariant with respect to a symmetry group give rise to emergent macroscopic levels organised into a hierarchy determined by the subgroups of the symmetry. >>

<< ️The same symmetries happen to also shape Bayesian beliefs, yielding hierarchies of abstract belief states that can be updated autonomously at different levels of resolution. These results are illustrated in Hopfield networks and Ehrenfest diffusion, showing that familiar macroscopic quantities emerge naturally from their symmetries. Together, these results suggest that symmetries provide a fundamental mechanism for emergence and support a structural correspondence between objective and epistemic processes, making feasible inferential problems that would otherwise be computationally intractable. >>

Fernando E. Rosas. Symmetries at the origin of hierarchical emergence. arXiv: 2512.00984v1 [q-bio.NC]. Nov 30, 2025.

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

Keywords: gst, networks, transitions, nested emergent layers, hierarchical emergences, subgroup symmetry, Bayesian beliefs, Hopfield networks, Ehrenfest diffusion.

mercoledì 10 dicembre 2025

# gst: degrees of universality in wave turbulence

<< ️Turbulence of weakly interacting waves displays a great deal of universality: independence of the details of the interaction and of the pumping and dissipation scales. Here (AA) study how inverse turbulent cascades (from small to large scales) transition from weak to strong. (They) find that while one-loop corrections can be dependent on excitation and dissipation scales, new types of universality appear in strong turbulence. (They) contrast turbulence of spin waves in ferromagnets with turbulent cascades in the Nonlinear Schrödinger Equation (NSE) and in an MMT-like (Majda-McLaughlin-Tabak) model in higher dimensions having a multiplicative interaction vertex: vertex renormalization gives rise to dependence on the pumping (UV scale) in the former but not in the latter. >>

<< ️As a result of this spectral nonlocality, spin-wave turbulence stops being weak if one is sufficiently far from the pumping scale, even when the interaction of waves with comparable wavenumbers is weak. (AA) paraphrase this as: nonlocality enhances nonlinearity. >>

<< ️(AA) then describe strong turbulence in a multi-component version of these models with a large number of components. (They) argue that strong spin-wave turbulence is similar to turbulence of the focusing NSE, as it realizes a critical-balance state. However, UV nonlocality causes the level of spin-wave turbulence at large scales to decrease with increasing pumping level, culminating in a state that is independent of the level of pumping. >>

Jiasheng Liu, Vladimir Rosenhaus, Gregory Falkovich. Degrees of universality in wave turbulence. arXiv: 2512.04866v1 [cond-mat.stat-mech]. Dec 4, 2025.

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

Keywords: gst, waves, turbulence, transitions.

giovedì 4 dicembre 2025

# gst: the way bubbles gallop.

<< ️Bubbles are more than fleeting pockets of air trapped in liquid: they exhibit an ever-expanding repertoire of intriguing behaviors. From da Vinci's sketches of their swirling paths to modern-day studies of their erratic dances under acoustic waves, the rich dynamics of bubbles have long captured the attention of everyday observers, engineers, and scientists alike. When exposed to periodic sound waves, bubbles can shift from regular pulsations to rapid zigzagging, mimicking the randomness of Brownian motion. Under sudden pressure changes, they may collapse violently, producing cavitation—intense shock waves capable of damaging solid surfaces. In extreme cases, the implosion may become so intense that the bubble emits a spark of light. >>

<< ️Bubbles can also challenge common intuition: they may appear to violate Archimedes' principle, sinking against gravity in oscillating fluids, and carbonated drinks. Despite centuries of explorations, new and often surprising bubble phenomena continue to emerge. One such example is the recently discovered “galloping” bubble, introduced in (AA) recent publication. Here, (They) showcase this new mechanism of bubble locomotion, highlighting its rich dynamics and striking visual appeal. >>

Jian H. Guan, Saiful I. Tamim, Connor W. Magoon, et al. The way bubbles gallop. Phys. Rev. Fluids 10, 110507. Nov 20, 2025.


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

Keywords: gst, bubble, galloping bubbles, galloping threshold, galloping motion, galloping mechanism, instability, galloping instability, drops, droplets, droploids, transitions.

martedì 2 dicembre 2025

# brain: meditative absorption shifts brain dynamics toward criticality.

<< ️Criticality describes a regime between order and chaos that supports flexible yet stable information processing. Here (AA) examine whether neural dynamics can be volitionally shifted toward criticality through the self-regulation of attention. >>

<< (They) examined ten experienced practitioners of meditation during a 10-day retreat, comparing refined states of meditative absorption, called the jhanas, to regular mindfulness of breathing. (They) collected electroencephalography (EEG) and physiological data during these practices and quantified the signal's dynamical properties using Lempel-Ziv complexity, signal entropy, chaoticity and long-range temporal correlations. In addition, (They) estimated perturbational sensitivity using a global auditory oddball mismatch negativity (MMN) during meditation. >>

<< ️Relative to mindfulness, jhana was associated with pronounced self-reported sensory fading, slower respiration, higher neural signal diversity across multiple measures, reduced chaoticity, and enhanced MMN amplitude over frontocentral sites. Spectral analyses showed a flatter aperiodic one over f component and a frequency-specific reorganization of long-range temporal correlations. Together, increased diversity with reduced chaoticity and heightened deviance detection indicate a shift toward a metastable, near-critical regime during jhana. >>

<< ️(AA) propose an overlap of the phenomenology of jhana with minimal phenomenal experiences in terms of progressive attenuation of sensory content with preserved tonic alertness. Accordingly, (Their) findings suggest that criticality is a candidate neurophysiological marker of the absorptive, minimal-content dimension of the minimal phenomenal experience. >>

Jonas Mago, Joshua Brahinsky, Mark Miller, et al. Meditative absorption shifts brain dynamics toward criticality. arXiv: 2511.20990v1 [q-bio.NC]. Nov 26, 2025.

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

Keywords: gst, brain, Zen, criticality, transitions, meditation, meditative absorption, jhanas, breathing mindfulness.