# gst: triadic instabilities of internal wave standing modes.

<< ️This (AA) article presents (their) experimental study of the nonlinear destabilization of an internal wave standing mode in a uniformly stratified fluid within a rectangular domain. (They) measure the linear response of the system and target its resonances to generate a high-amplitude standing mode, prone to instabilities. Using modal decomposition tools, (They) determine the characteristics of the secondary waves and show that they have a standing-mode spatial structure. Box resonance conditions associated with nonlinear resonance conditions lead to a significant deviation from the internal wave dispersion relation and complex nonlinear interaction dynamics. >>

<< Following previous work, (AA) develop a weakly nonlinear analysis to understand the secondary wave characteristics. This approach, validated by experimental results, shows that the secondary wave characteristics as well as the general nonlinear dynamics are highly sensitive to the domain geometry and to the forcing mode. >>

Julie Deleuze, Ilias Sibgatullin, Philippe Odier, Sylvain Joubaud. Triadic instabilities of internal wave standing modes. Phys. Rev. Fluids 10, 124803. Dec 8, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/2pvv-wkc4

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

Keywords: gst, waves, instability.

# 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.

https://journals.aps.org/pre/abstract/10.1103/wtrv-4g4h

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

https://arxiv.org/abs/2506.11433

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

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

# 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.

https://arxiv.org/abs/2512.17816

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.

# 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.

https://arxiv.org/abs/2512.05856

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

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

# gst: bursting bubbles in Herschel-Bulkley fluids, dynamics and jetting transitions.

<< ️When a bubble rises to a free surface, its bursting dynamics in Newtonian fluids are governed by the interplay between viscous, capillary, and gravitational forces. In this work, (AA) extend this classical problem to Herschel-Bulkley fluids, elucidating the role of viscoplasticity and non-Newtonian rheology in bubble bursting. Using direct numerical simulations validated against experiments, (They) systematically explore the influence of the key governing dimensionless parameters, such as the Bond number, the Ohnesorge number, the shear-dependent behavior and the plastocapillary number, each varied over several orders of magnitude. >>

<< ️(AA) results reveal that viscoplasticity strongly controls the evolution and interaction of capillary waves within the cavity formed upon bubble rupture. Shear-thinning and shear-thickening effects are significant only for moderate Ohnesorge numbers, while at large Ohnesorge values the free surface dynamics converge to a non-flat equilibrium shape once the internal stresses fall below the yield stress. >>

<< ️These (AA) findings provide new insights into the coupled effects of viscosity, gravity, yield stress, and shear-dependent rheology in multiphase flows, with broad implications for natural and industrial processes involving gas-liquid interfaces. >>

A. H. Ghaemi, Z. Yang, A. Huang, et al. Bursting bubbles in Herschel-Bulkley fluids: dynamics and jetting transitions. arXiv: 2511.23345v1 [physics.flu-dyn]. Nov 28, 2025.

https://arxiv.org/abs/2511.23345

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

Keywords: gst, bubble, waves, capillary waves, bubble bursting, bubble rupture, viscosity, capillary and gravitational forces, shear-thinning and shear-thickening effects, yield stress, free surface dynamics, non-flat equilibrium.

# 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.

https://arxiv.org/abs/2512.02331

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

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

# 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

https://journals.aps.org/prfluids/abstract/10.1103/nvkn-hk4g

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

https://gfm.aps.org/meetings/dfd-2024/673f8914d88f37002bbe76d8

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

Keywords: gst, waves, instability, transitions.

# 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.

https://arxiv.org/abs/2512.00984

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.

# gst: atypical chimera states in an ensemble of partially mobile particles.

<< ️(AA) study the influence of nonuniform motion of oscillators in a ring chain with nonlocal coupling on their collective dynamics and reveal the mechanism behind the emergence of an atypical chimera state in such systems. >>

<< ️The mechanism relies on regular spatially inhomogeneous motion of oscillators, which breaks the symmetry of the effective interaction kernel. This symmetry breaking induces spatial phase correlations in the asynchronous part of the system, giving rise to nonuniformly twisted and previously unobserved coherent-incoherent-twisted states. >>

Pavel A. Shcherbakov, Lev A. Smirnov, Vasily A. Kostin, et al. Atypical Chimera States in an Ensemble of Partially Mobile Particles. arXiv: 2512.00876v1 [nlin.PS]. Nov 30, 2025. 

https://arxiv.org/abs/2512.00876

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

Keywords: gst, chimera, phase oscillators, nonlocal coupling, active particles, twisted state, alternating chimera state, cross-correlation.

# 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.

https://arxiv.org/abs/2512.04866

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

Keywords: gst, waves, turbulence, transitions.

# gst: apropos of escape, qualitatively distinct mechanisms of noise-induced escape in diffusively coupled bistable elements.

<< ️The analysis of noise-induced escape in ensembles of bistable elements is challenging, because nonlinearity, coupling, and noise all play essential roles. (AA) show that the interplay of these three factors yields three qualitatively distinct escape mechanisms in diffusively coupled bistable elements, depending on the coupling strength. >> 

<< ️To clarify the relation between coupling strength and mean escape time, (They) derive effective one-dimensional dynamics: nonlinear mean-field Fokker-Planck equation in the weak-coupling regime, stochastic mean-field dynamics in the strong-coupling regime, and deterministic mean-field dynamics in the intermediate regime. >>

<< ️(AA) validate these reduced descriptions by comparing predictions with numerical simulations. (They) identify a distinct dominant driving factor of escape processes in each regime. Notably, the three escape mechanisms emerge through the interplay of nonlinearity, diffusive coupling, and dynamical noise -- rather than bifurcations of the noise-free system. >>

<< ️(AA) approach serves as a framework applicable to other diffusively coupled stochastic nonlinear systems, motivating a further search for similar synergistic phenomena. >>

Hidemasa Ishii, Hiroshi Kori. Qualitatively distinct mechanisms of noise-induced escape in diffusively coupled bistable elements. arXiv: 2512.01388v1 [nlin.AO]. Dec 1, 2025.

https://arxiv.org/abs/2512.01388

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

Keywords: gst, noise, escape, noise-induced escape, bistable elements, weak- mean- strong- regimes, stochasticity.

# gst: finding information in the randomness of living matter.

<< ️In recent research, (AA) succeeded in developing a theoretical description that can rigorously characterize the role of fluctuations in systems. "It is mathematically challenging to predict the behavior of such systems if using traditional tools from statistical mechanics," (Martin Kjøllesdal Johnsrud) >>.

<< ️The physicists thus developed a suitable mathematical tool to extend the existing field theories, and they are now able to make predictions about systems out of equilibrium, such as active matter. "With our formalism, we are able to define measurable quantities that can help to characterize nonequilibrium dynamics of living matter and enable experimental design of artificial active systems," (Ramin Golestanian) >>. 

Manuel Maidorn. Finding information in the randomness of living matter. Phys.org. Nov 28, 2025.

https://phys.org/news/2025-11-randomness.html

Martin Kjøllesdal Johnsrud, Ramin Golestanian. Phys. Rev. Research 7, L032053. Sep 9, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/xx4z-lj5c

Martin Kjøllesdal Johnsrud, Ramin Golestanian. Phys. Rev. Research 7, L032054. Sep 9, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/flzv-lq7x

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

Keywords: gst, active matter, complex systems, microscopic fluctuations, noise, nonequilibrium dynamics, stochastic field theories, statistical mechanics.

#qubit: more in quantum weirdness, the superposition of unitaries (a particle simultaneously follows two distinct sets of movement instructions)

<< ️Arijit Chatterjee at the Indian Institute of Science Education and Research and his colleagues theorized that a new kind of quantum motion, in which a particle follows two distinct sets of movement instructions simultaneously, (..). They called this superposition of unitaries. >>

Paul Arnold. Experimental proof shows quantum world is even stranger than previously thought. Phys.org. Nov 25, 2025.

https://phys.org/news/2025-11-experimental-proof-quantum-world-stranger.html

Arijit Chatterjee, H.S. Karthik, T.S. Mahesh, A.R. Usha Devi. Enhanced non-macrorealism: Extreme violations of Leggett-Garg inequalities for a system evolving under superposition of 

unitaries. arXiv: 2411.02301v1 [quant-ph]. Nov 4, 2024. https://arxiv.org/abs/2411.02301.  Phys. Rev. Lett. 135, 220202. Nov 24, 2025. https://journals.aps.org/prl/abstract/10.1103/vydp-9qqq

Keywords: qubit, quantum systems & decoherence, quantum-to-classical transition.

# 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.

https://journals.aps.org/prfluids/abstract/10.1103/fbdh-fnzv

Gallery of Fluid Motion. https://doi.org/10.1103/APS.DFD.2024.GFM.V2684816

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.

# 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.

https://arxiv.org/abs/2511.20990

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

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

# gst: apropos of Parrondo paradox, controlling quantum chaos via Parrondo strategies on noisy intermediate-scale quantum hardware

<< ️Advancements in noisy intermediate-scale quantum (NISQ) computing are steadily pushing these systems toward outperforming classical supercomputers on specific well-defined computational tasks. In this work (AA) explore and control quantum chaos in NISQ systems using discrete-time quantum walks (DTQWs) on cyclic graphs. To efficiently implement quantum walks on NISQ hardware, (They) employ the quantum Fourier transform to diagonalize the conditional shift operator, optimizing circuit depth and fidelity. >>

<< ️(AA) experimentally realize the transition from quantum chaos to order via DTQW dynamics on both odd and even cyclic graphs, specifically 3- and 4-cycle graphs, using the counterintuitive Parrondo paradox strategy across three different NISQ devices. >>

<< ️While the 4-cycle graphs exhibit high-fidelity quantum evolution, the 3-cycle implementation shows significant fidelity improvement when augmented with dynamical decoupling pulses. (Their) results demonstrate a practical approach to probing and harnessing controlled chaotic dynamics on real quantum hardware, laying the groundwork for future quantum algorithms and cryptographic protocols based on quantum walks. >>

Aditi Rath, Dinesh Kumar Panda, Colin Benjamin. Controlling quantum chaos via Parrondo strategies on noisy intermediate-scale quantum hardware. Phys. Rev. E 112, 054219. Nov 18, 2025.

https://journals.aps.org/pre/abstract/10.1103/m89r-2dy5

arXiv: 2506.11225v2 [quant-ph]. Nov 4, 2025.

https://arxiv.org/abs/2506.11225

Also: parrondo, noise, walk, walking, order, chaos, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, parrondo, noise, walk, walking, quantum walk, order, chaos, quantum chaos, transition, dynamical decoupling pulses, cryptography.

# gst: prone to flooding or steady planing state transitions; dynamics of levitation during rolling over a thin viscous film.

<< ️A mathematical model is derived for the dynamics of a cylinder, or wheel, rolling over a thin viscous film. The model combines the Reynolds lubrication equation for the fluid with an equation of motion for the wheel. Two asymptotic limits are studied in detail to interrogate the dynamics of levitation: an infinitely wide wheel and a relatively narrow one. In both cases the front and back of the fluid-filled gap are either straight or nearly so. >>

<< ️To bridge the gap between these two asymptotic limits, wheels of finite width are considered, introducing a further simplying approximation: although the front and back are no longer expected to remain straight for a finite width, the footprint of the fluid-filled gap is still taken to be rectangular, with boundary conditions imposed at the front and back in a wheel-averaged sense. The Reynolds equation can then be solved by separation of variables. >>

<< ️For wider wheels, with a large amount of incoming flux or a relatively heavy loading of the wheel, the system is prone to flooding by back flow with fluid unable to pass underneath. Otherwise steady planing states are achieved. >>

<< ️Both lift-off and touch-down are explored for a wheel rolling over a film of finite length. Theoretical predictions are compared with a set of experimental data. >>

Siqi Chen, Cheng Liu, Neil J. Balmforth, et al. Dynamics of levitation during rolling over a thin viscous film. arXiv: 2511.12441v1 [physics.flu-dyn]. Nov 16, 2025.

https://arxiv.org/abs/2511.12441

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

Keywords: gst, transitions, viscosity, rolling, boundary conditions, levitation.

# gst: topological transitions in swarmalators systems.

<< ️After its development, the swarmalators model attracted a great deal of attention since it was found to be very suitable to reproduce several behaviors in collective dynamics. However, few works explain the transitions that are observed while varying system parameters. >>

<< ️In this letter, (AA) demonstrate that the changes observed in swarmalator dynamics are governed by changes in the system's topology. To provide a deeper understanding of these changes, (They) present a topological framework for the swarmalator system and determine the topological charge Q and the helicity γ of the corresponding topology. Investigations on synchronization and transition to synchronization are studied using this topological charge and the variance of the helicity. >>

Patrick Louodop, Michael N. Jipdi, Gael R. Simo, et al. Topological transitions in swarmalators systems. arXiv: 2511.13490v1 [nlin.AO]. Nov 17, 2025.

https://arxiv.org/abs/2511.13490

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

Keywords: gst, swarm, swarmalators, transitions, chimera, collective dynamics, topological charge, helicity, non-topological chimera, transition to synchronization.

# gst: spontaneous emergence of solitary waves in active flow networks.

<< ️Flow networks are fundamental for understanding systems such as animal and plant vasculature or power distribution grids. These networks can encode, transmit, and transform information embodied in the spatial and temporal distribution of their flows. >>

<< ️In this work, (AA) focus on a minimal yet physically grounded system that allows (Them) to isolate the fundamental mechanisms by which active flow networks generate and regulate emergent dynamics capable of supporting information transmission. The system is composed of active units that pump fluid and elastic units that store volume. From first principles, (They) derive a discrete model-an active flow network-that enables the simulation of large systems with many interacting units. >>

<< ️Numerically, (AA) show that the pressure field can develop solitary waves, resulting in the spontaneous creation and transmission of localized packets of information stored in the physical properties of the flow. (They) characterize how these solitary waves emerge from disordered initial conditions in a one-dimensional network, and how their size and propagation speed depend on key system parameters. >>

<< ️Finally, when the elastic units are coupled to their neighbors, the solitary waves exhibit even richer dynamics, with diverse shapes and finite lifetimes that display power-law behaviors that (They) can predict analytically. >>

Rodrigo Fernández-Quevedo García, Gonçalo Cruz Antunes, Jens Harting, et al. Spontaneous emergence of solitary waves in active flow networks. arXiv: 2511.13448v1 [physics.flu-dyn]. Nov 17, 2025.

https://arxiv.org/abs/2511.13448

Also: soliton, waves, network, elastic, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, solitons, waves, solitary waves, networks, active flow networks, active matter, fluid-structure interactions, elasticity.

# gst: turbulence at low Reynolds numbers.

<< ️Turbulence -- ubiquitous in nature and engineering alike  -- is traditionally viewed as an intrinsically inertial phenomenon, emerging only when the Reynolds number (Re), which quantifies the ratio of inertial to dissipative forces, far exceeds unity. >>

<< ️Here, (AA) demonstrate that strong energy flux between different length scales of motion -- a defining hallmark of turbulence -- can persist even at Re ~ 1, thereby extending the known regime of turbulent flows beyond the classical high-Re paradigm. (They) show that scale-to-scale energy transfer can be recast as a mechanical process between turbulent stress and large-scale flow deformation. >>

<< ️In quasi-two-dimensional (quasi-2D) flows driven by electromagnetic forcing, (They) introduce directionally biased perturbations that enhance this interaction, amplifying the spectral energy flux by more than two orders of magnitude, even in the absence of dominant inertial forces. >>

<< ️This (AA) study establishes a new regime of 2D Navier-Stokes (N-S) turbulence, challenging long-standing assumptions about the high Re conditions required for turbulent flows. Beyond revising classical belief, (Their) results offer a generalizable strategy for engineering multiscale transport in flows that lack inertial dominance, such as those found in microfluidic and low-Re biological systems. >>

Ziyue Yu, Xinyu Si, Lei Fang. Turbulence at Low Reynolds Numbers. arXiv: 2511.05800v1 [physics.flu-dyn]. Nov 8, 2025.

https://arxiv.org/abs/2511.05800

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

Keywords: gst, turbulence, chaos,  transitions.

# gst: geometric intermittency in turbulence.

<< ️Equal-time scaling exponents in fully developed turbulence typically exhibit non anomalous scaling in the inverse cascade of two-dimensional (2D) turbulence and anomalous scaling in three dimensions. >>

<< ️(AA) have shown that intermittency in turbulence is not exhausted by longitudinal and transverse velocity increments: geometric increments of the velocity field display equally strong, and in some regimes stronger, multiscaling. This reveals a previously hidden intermittency in the 2D inverse cascade and identifies a universal class of geometric scaling exponents. >>

<< ️This, of course, leads to questions of whether long-lived vortical structures play a more significant role in making flows intermittent, especially in 2D, than appreciated hitherto. >>

<< ️(AA) results also suggest that the geometry of turbulent velocity fields plays a fundamental role in cascade dynamics and opens a route to probing intermittency, blind to conventional structure functions, in other flows. >>

Ritwik Mukherjee, Siddhartha Mukherjee, I. V. Kolokolov, et al. Geometric Intermittency in Turbulence. arXiv: 2511.06439v1 [physics.flu-dyn]. Nov 9, 2025.

https://arxiv.org/abs/2511.06439

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

Keywords: gst, turbulence, intermittency, cascade dynamics, multiscaling, multiscaling 2D inverse cascade, 

# gst: apropos of itinerant behaviors, from chaotic itinerancy to intermittent synchronization in complex networks.

<< ️Although synchronization has been extensively studied, important processes underlying its emergence have remained hidden by the use of global order parameters. Here, (AA) uncover how the route unfolds through a sequential transition between two well-known but previously unconnected phenomena: chaotic itinerancy (CI) and intermittent synchronization (IS). >>

<< ️Using a new symbolic dynamics, (They) show that CI emerges as a collective yet unsynchronized exploration of different domains of the high-dimensional attractor, whose dimension is reduced as the coupling increases, ultimately collapsing back into the reference chaotic attractor of an individual unit. At this stage, the IS can emerge as irregular alternations between synchronous and asynchronous phases. The two phenomena are therefore mutually exclusive, each dominating a distinct coupling interval and governed by different mechanisms. >>

<< ️Network structural heterogeneity enhances itinerant behavior since access to different domains of the attractor depends on the nodes' topological roles. The CI--IS crossover occurs within a consistent coupling interval across models and topologies. Experiments on electronic oscillator networks confirm this two-step process, establishing a unified framework for the route to synchronization in complex systems. >>

I. Leyva, Irene Sendiña-Nadal, Christophe Letellier, et al. From chaotic itinerancy to intermittent synchronization in complex networks. arXiv: 2511.09253v1 [nlin.AO]. Nov 12, 2025.

https://arxiv.org/abs/2511.09253

Also: network, behav, intermittency, transition, attractor, chaos, collapse, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, networks, behavior, intermittency, transitions, attractor, chaos, collapse, chaotic itinerancy, intermittent synchronization, structural heterogeneity, itinerant behavior.

# gst: effect of stochasticity on initial transients and chaotic itinerancy for a natural circulation loop.

<< ️The introduction of stochastic forcing to dynamical systems has been shown to induce qualitatively different behaviors, such as attractor hopping, to otherwise stable systems as they approach bifurcation. In this (AA) study, the effect of stochastic forcing on systems that have already undergone bifurcation and evolve on a chaotic attractor is explored. Markov and state-independent models of turbulence-induced stochasticity are developed, and their effects on a natural circulation loop operating in the chaotic regime are compared. >>

<< ️Stochasticity introduces considerable uncertainty into the duration of the initial chaotic transient but tends to accelerate it on average. An Ornstein-Uhlenbeck model of turbulent fluctuations is shown to produce results equivalent to a bootstrapped raw direct numerical simulation signal. >>

<< Similar, though less pronounced, effects are found for systems operating in the chaotic itinerant regime. The Markov model of chaotic itinerancy which is typically applied to this class of problems is shown to be invalid for this system and the Lorenz system, to which it has been applied in the past. >>

<< ️Off-discrete transitions and an upper limit on the time between flow reversals are explained by near misses of the attractor ruins caused by lingering excitation of high-order modes during chaotic itinerancy. >>

John Matulis, Hitesh Bindra. Effect of stochasticity on initial transients and chaotic itinerancy for a natural circulation loop. Phys. Rev. E 112, 044223. Oct 23, 2025

https://journals.aps.org/pre/abstract/10.1103/42pn-wttx

Also: disorder & fluctuations, turbulence, attractor, chaos, transition, uncertainty, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, fluctuations, turbulence, attractor, chaos, transition, uncertainty, stochasticity, flow instability, chaotic itinerancy, noise-induced transitions.

# gst: vorticity-induced surfing and trapping in porous media

<< Microorganisms often encounter strong confinement and complex hydrodynamic flows while navigating their habitats. Combining finite-element methods and stochastic simulations, (AA) study the interplay of active transport and heterogeneous flows in dense porous channels. (They) find that swimming always slows down the traversal of agents across the channel, giving rise to robust power-law tails of their exit-time distributions. These exit-time distributions collapse onto a universal master curve with a scaling exponent of ≈ 3/2 across a wide range of packing fractions and motility parameters, which can be rationalized by a scaling relation. >> 

<< ️(AA) further identify a new motility pattern where agents alternate between surfing along fast streams and extended trapping phases, the latter determining the power-law exponent. Unexpectedly, trapping occurs in the flow backbone itself -- not only at obstacle boundaries -- due to vorticity-induced reorientation in the highly-heterogeneous fluid environment. >>

Pallabi Das, Mirko Residori, Axel Voigt, et al. Vorticity-induced surfing and trapping in porous media. arXiv: 2511.02471v1 [cond-mat.soft]. Nov 4, 2025.

https://arxiv.org/abs/2511.02471

Also: swim, microswimmers, intermittency, disorder, vortex, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, swim, microswimmers, intermittency, disorder, vortex, self-propel, run-and-tumble dynamics, hop-and-trap pattern, surf-and-trap motility pattern.

# gst: implementation of a generalized intermittency scenario in the Rossler dynamical system.

<< The realization of novel scenario involving transitions between different types of chaotic attractors is investigated for the Rossler system. Characteristic features indicative of the presence of generalized intermittency scenario in this system are identified. The properties of "chaos-chaos" transitions following the generalized intermittency scenario are analyzed in detail based on phase-parametric characteristics, Lyapunov characteristic exponents, phase portraits, and Poincare sections. >>

O.O. Horchakov, A.Yu. Shvets. Implementation of a generalized intermittency scenario in the Rossler dynamical system. arXiv: 2511.03364v1 [nlin.CD]. Nov 5, 2025.

https://arxiv.org/abs/2511.03364

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

Keywords: gst, intermittency, attractors, chaos, transitions, chaos-chaos transitions.

# gst: experimental observation of hidden multistability in nonlinear systems.

<< ️Multistability, the coexistence of multiple stable states, is a cornerstone of nonlinear dynamical systems, governing their equilibrium, tunability, and emergent complexity. Recently, the concept of hidden multistability, where certain stable states evade detection via conventional continuous parameter sweeping, has garnered increasing attention due to its elusive nature and promising applications.  >>

<< ️In this Letter, (AA) present the first experimental observation of hidden multistability using a programmable acoustic coupled-cavity platform that integrates competing self-focusing and self-defocusing Kerr nonlinearities. Beyond established bistability, (They) demonstrate semi- and fully-hidden tristabilities by precisely programming system parameters. Crucially, the hidden stable states, typically inaccessible via the traditional protocol, are unambiguously revealed and dynamically controlled through pulsed excitation, enabling flexible transitions between distinct types of stable states. >>

Kun Zhang, Qicheng Zhang, Shuaishuai Tong, et al. Experimental Observation of Hidden Multistability in Nonlinear Systems. arXiv: 2511.04150v1 [nlin.CD]. Nov 6, 2025.

https://arxiv.org/abs/2511.04150

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

Keywords: gst, stability, multistability, hidden multistability, semi- fully-hidden tristabilities, pulsed excitation.

# gst: energy transport and chaos in a one-dimensional disordered nonlinear stub lattice

<< ️(AA) investigate energy propagation in a one-dimensional stub lattice in the presence of both disorder and nonlinearity. In the periodic case, the stub lattice hosts two dispersive bands separated by a flat band; however, (They) show that sufficiently strong disorder fills all intermediate band gaps. By mapping the two-dimensional parameter space of disorder and nonlinearity, (AA) identify three distinct dynamical regimes (weak chaos, strong chaos, and self-trapping) through numerical simulations of initially localized wave packets. >>

<< ️When disorder is strong enough to close the frequency gaps, the results closely resemble those obtained in the one-dimensional disordered discrete nonlinear Schrödinger equation and Klein-Gordon lattice model. In particular, subdiffusive spreading is observed in both the weak and strong chaos regimes, with the second moment m_2 of the norm distribution scaling as m_2 ∝ t^0.33 and m_2 ∝ t^0.5, respectively. The system’s chaotic behavior follows a similar trend, with the finite-time maximum Lyapunov exponent Λ decaying as Λ ∝ t^−0.25 and Λ ∝ t^−0.3. For moderate disorder strengths, i.e., near the point of gap closing, (They) find that the presence of small frequency gaps does not exert any noticeable influence on the spreading behavior. >>

<< ️(AA) findings extend the characterization of nonlinear disordered lattices in both weak and strong chaos regimes to other network geometries, such as the stub lattice, which serves as a representative flat-band system. >>

Su Ho Cheong, Arnold Ngapasare, et al. Energy transport and chaos in a one-dimensional disordered nonlinear stub lattice. arXiv: 2511.04159v1 [nlin.CD].  Nov 6, 2025.

https://arxiv.org/abs/2511.04159

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

Keywords: gst, networks, waves, disorder, chaos, stub lattice, subdiffusive spreading.

# gst: dynamical phase transitions across slow and fast regimes in a two-tone driven Duffing resonator

<< In this work, (AA) established an analytical framework to describe dynamical phase transitions in a Duffing resonator under bichromatic driving. (They) reveal two regimes: a slow-beating one, where the secondary tone slowly modulates the main drive and can push the system past bifurcations, and a fast-modulation one. >>

<< (AA) analysis shows that even a weak secondary tone can profoundly reshape the dynamics, inducing transitions between coexisting attractors that cannot be explained by perturbative treatments of the secondary tone. >>

<< This provides a qualitative yet predictive tool to detect and categorize different types of dynamical phase transitions in two-tone driven nonlinear systems. >>

Soumya S. Kumar, Javier del Pino, et al. Dynamical Phase Transitions Across Slow and Fast Regimes in a Two-Tone Driven Duffing Resonator. arXiv: 2511.01985v1 [cond-mat.mes-hall]. Nov 3, 2025.

https://arxiv.org/abs/2511.01985

 

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

Keywords: gst, attractor, transitions, chaos,  Duffing resonator, bichromatic driving. 

# gst: apropos of shape transitions, midveins regulate the shape formation of drying leaves.

<< ️Dried leaves in nature often exhibit curled and crumpled morphologies, typically attributed to internal strain gradients that produce dome-like shapes. However, the origin of these strain gradients remains poorly understood. Although leaf veins--particularly the midvein--have been suggested to influence shape formation, their mechanical role has not been systematically investigated. >>

<< ️Here, (AA) demonstrate that mechanical constraints imposed by the midvein play a crucial role in generating the diverse morphologies that emerge during leaf drying. Combining numerical simulations and theoretical analysis, (They) show that a uniformly shrinking leaf lamina constrained by a non-shrinking midvein gives rise to two distinct types of configurations: curling-dominated and folding-dominated morphologies. In the curling-dominated regime, both S-curled and C-curled shapes emerge, with C-curled configurations more commonly observed due to their lower elastic energy. In contrast, the folding-dominated regime features folding accompanied by edge waviness. Theoretical modeling reveals a linear relationship between midvein curvature and mismatch strain, consistent with simulation results. >>

<< ️Moreover, (AA) find that the morphological outcome is governed by the ratio of bending stiffnesses between the lamina and the midvein. (They) construct a comprehensive phase diagram for the transitions between different configurations. These findings provide a mechanical framework for understanding shape formation in drying leaves, offering new insights into natural morphing processes and informing the design of bio-inspired morphable structures. >>

Kexin Guo, Yafei Zhang, et al. Midveins regulate the shape formation of drying leaves. arXiv: 2507.01813v1 [cond-mat.soft]. Jul 2, 2025.

https://arxiv.org/abs/2507.01813

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

Keywords: gst, waves, transition, leaf drying, curled and crumpled morphologies, internal strain gradients, dome-like shapes, curling-dominated and folding-dominated morphologies, edge waviness, midvein curvature and mismatch strain, life.

# life: apropos of immigration problems, 'China is going to win the AI race', by Jensen.

<< ️"As I have long said, China is nanoseconds behind America in AI," Nvidia CEO Jensen Huang said in a statement posted on X late on Wednesday. >>

<< ️"A policy that causes America to lose half of the world's AI developers is not beneficial in the long term, it hurts us more," >>

Nvidia's Jensen Huang: 'China is going to win the AI race,' FT reports. Reuters. Nov 6, 2025.

https://www.reuters.com/world/asia-pacific/nvidias-jensen-huang-says-china-will-win-ai-race-with-us-ft-reports-2025-11-05/  Nvidia’s Jensen Huang says China ‘will win’ AI race with US.  https://www.ft.com/content/53295276-ba8d-4ec2-b0de-081e73b3ba43 

Also: life, ai (artificial intell) (bot), in https://www.inkgmr.net/kwrds.html 

Keywords: life, aibot, artificial intelligence.

# gst: a probability space at inception of stochastic process.

<< ️Recently, progress has been made in the theory of turbulence, which provides a framework on how a deterministic process changes to a stochastic one owing to the change in thermodynamic states. It is well known that, in the framework of Newtonian mechanics, motions are dissipative; however, when subjected to periodic motion, a system can produce nondissipative motions intermittently and subject to resonance. It is in resonance that turbulence occurs in fluid flow, solid vibration, thermal transport, etc. In this, the findings from these physical systems are analyzed in the framework of statistics with their own probability space to establish their compliance to the stochastic process. >>

<< ️In particular, a systematic alignment of the inception of the stochastic process with the signed measure theory, signed probability space, and stochastic process was investigated. It was found that the oscillatory load from the dissipative state excited the system and resulted in a quasi-periodic probability density function with the negative probability regimes. In addition, the vectorial nature of the random velocity splits the probability density function along both the positive and negative axes with slight asymmetricity. By assuming that a deterministic process has a probability of 1, (AA) can express the inception of a stochastic process, and the subsequent benefit is that a dynamic fractal falls on the probability density function. Moreover, (They) leave some questions of inconsistency between the physical system and the measurement theory for future investigation. >>

Liteng Yang, Yuliang Liu, et al. A Probability Space at Inception of Stochastic Process. arXiv: 2510.20824v1 [nlin.CD]. Oct 8, 2025.

https://arxiv.org/abs/2510.20824

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

Keywords: gst, turbulence, dissipation, intermittency, randomness, transitions.

# gst: long-range resonances in quasiperiodic many-body localization.

<< ️(AA) investigate long-range resonances in quasiperiodic many-body localized (MBL) systems. (..) Contrary to the expectation that the ergodic-MBL transition in quasiperiodic systems should be sharper due to the absence of Griffiths regions, (They) uncover a broad unconventional regime at strong quasiperiodic potential, characterized by fat-tailed distributions of longitudinal correlations at long distance. This reveals the presence of atypical eigenstates with strong long-range correlations in a regime where standard diagnostics indicate stable MBL. >>

<< ️(AA) further identify these anomalous eigenstates as quasi-degenerate pairs of resonant cat states, which exhibit entanglement at long distance. These findings advance the understanding of quasiperiodic MBL and identify density-correlation measurements in ultracold atomic systems as a probe of long-range resonances. >>

Ashirbad Padhan, Jeanne Colbois, et al. Long-range resonances in quasiperiodic many-body localization. arXiv: 2510.24704v1 [cond-mat.dis-nn]. Oct 28, 2025.

https://arxiv.org/abs/2510.24704

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

Keywords: gst, order, disorder, transitions, interplay between disorder and interactions, long-range resonances, strong long-range correlations, many-body localization (MBL), entanglement at long distance, atypical eigenstates.

# gst: emergence of chimeras states in one-dimensional Ising model with long-range diffusion.

<< ️In this work, (AA) examine the conditions for the emergence of chimera-like states in Ising systems. (They) study an Ising chain with periodic boundaries in contact with a thermal bath at temperature T, that induces stochastic changes in spin variables. To capture the non-locality needed for chimera formation, (They) introduce a model setup with non-local diffusion of spin values through the whole system. More precisely, diffusion is modeled through spin-exchange interactions between units up to a distance R, using Kawasaki dynamics. This setup mimics, e.g., neural media, as the brain, in the presence of electrical (diffusive) interactions. >>

<< ️(AA) explored the influence of such non-local dynamics on the emergence of complex spatiotemporal synchronization patterns of activity. Depending on system parameters (They) report here for the first time chimera-like states in the Ising model, characterized by relatively stable moving domains of spins with different local magnetization. (They) analyzed the system at T=0, both analytically and via simulations and computed the system's phase diagram, revealing rich behavior: regions with only chimeras, coexistence of chimeras and stable domains, and metastable chimeras that decay into uniform stable domains. >>

<< ️This study offers fundamental insights into how coherent and incoherent synchronization patterns can arise in complex networked systems as it is, e.g., the brain. >>

Alejandro de Haro García, Joaquín J. Torres. Emergence of Chimeras States in One-dimensional Ising model with Long-Range Diffusion. arXiv: 2510.24903v1 [cond-mat.dis-nn]. Oct 28, 2025. 

https://arxiv.org/abs/2510.24903

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

Keywords: gst, chimera, Ising systems, stochasticity, networks, brain.

# gst: cascade tipping, cascade hopping and indirect tipping in ecological systems.

<< ️Tipping occurs when an abrupt transition is observed in a system's long-term behavior. This study demonstrates tipping in ecological systems using a unidirectional, three-species coupled system, where only the first subsystem experiences a ramp-like parameter drift. Using a model of bacteria, phytoplankton, and fish populations, (AA) explore how environmental changes, coupling strength, and nonlinearity drive sudden transitions.  >>

<< ️This (AA) study identifies three crucial tipping phenomena based on the coupling strength: tipping cascade, cascade hopping, and indirect tipping. While prior research has focused on tipping cascade and cascade hopping, this work introduces indirect tipping as a critical phenomenon, where the tertiary subsystem tips even when both the primary and secondary subsystems do not tip. The results emphasize the vulnerability of coupled systems to minor changes and highlight the necessity of closely observing systems that appear untipped in coupled systems. >>

Ayanava Basak, Syamal Kumar Dana, Nandadulal Bairagi. Cascade tipping, cascade hopping and indirect tipping in ecological systems. Phys. Rev. E 112, 044225. Oct 24, 2025.

https://journals.aps.org/pre/abstract/10.1103/sn5v-xyb5

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

Keywords: gst, transitions, cascade tipping, cascade hopping, indirect tipping.

# gst: coupling an elastic string to an active bath: the emergence of inverse damping.

<< ️The interaction between continuous media and particles is a central topic in much of modern physics, and this (AA) paper specifically addresses the transfer of persistence and activity between particles and waves. Indeed, setting up a nonequilibrium dynamics of continuous (field) degrees of freedom requires understanding how that arises from coupling with active matter degrees of freedom. >>

<< ️Within that program, (AA) have studied a system of fast-moving, overdamped, run-and-tumble particles moving on and interacting with a slower string modeled as a scalar Klein-Gordon field. Using time scale separation and weak coupling, (They) have derived an effective fluctuation dynamics for the field after integrating out the active bath. Akin to Landau (inverse) damping, the particles induce friction on the scalar field given by an explicit time correlation for bath observables. >>

<< ️Depending on the level of activity and persistence of the active particles (and their velocity distribution), this friction can be negative, leading to instability. This emergence of negative (linear) friction for an elastic string extends previous results where the probe is a slow inertial particle in an active medium, (..), except that the acceleration (creating transverse waves) is orthogonal to the active motion. >>

Aaron Beyen, Christian Maes, Ji-Hui Pei. Coupling an elastic string to an active bath: The emergence of inverse damping. arXiv: 2505.18665v2 [cond-mat.stat-mech]. Sep 1, 2025.

https://arxiv.org/abs/2505.18665

Phys. Rev. E 112, L042103. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/g1zm-23sq

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

Keywords: gst, particles, run-and-tumble particles, waves, elasticity, elastic strings, wave-particle interactions.

# gst: cascade crack in chain of beads.

<< ️(AA) consider a homogeneous chain of spheres linked by liquid bridges under tension. The rupture of a single liquid bridge leads to a fragmentation cascade driven by the inverse relation between the capillary force and the sphere distances. The initial length of the liquid bridges determines the number and size of the fragments and the velocity of the fragmentation front. >>

Meysam Bagheri, Thorsten Pöschel. Cascade Crack in Chain of Beads. arXiv: 2508.01288v1 [cond-mat.soft]. Aug 2, 2025.

https://arxiv.org/abs/2508.01288

Phys. Rev. E 112, 045414. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/hzs3-8ffk

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

Keywords: gst, crack, fracture, fragmentation cascade.

# gst: transition to chaos with conical billiards.

<< ️In this paper, (AA) introduced and extensively investigated dynamical billiards on the surface of a cone with a tilted base. Upon varying the cone angle β, corresponding to a deficit angle 

2πχ = 2π(1 − sin(β)), and tilt angle γ, (They) identified three distinct types of trajectories with associated Poincaré map for conical billiards: rim, hourglass, and mixed. >>

<< ️Region I, where Poincaré space consists of rim, hourglass, and mixed trajectories; Region IIB, where Poincaré space consists of only hourglass and mixed trajectories; and Region IIA, in which (They) find choices of γ and χ for which almost all trajectories are strongly mixing. (..) (AA) also developed a scheme for identifying strongly mixing trajectories. >>

<< ️Furthermore, (They) were able to show that a dynamical billiard on a surface with exclusively convex and positive Gaussian curvature in three dimensions can still exhibit ergodic behavior in certain parameter regimes. >>

<< ️A particularly intriguing feature of this system is that by tuning χ and γ, nearly all points in (θ,ϕ) Poincaré space describing conical line segments in between bounces can be placed at the edge between chaotic and integrable dynamics. Thus this work highlights the potential of conical billiards as a model system for exploring intriguing problems inspired by neural networks at the “edge of chaos”. >>

Lara Braverman, David R. Nelson. Transition to chaos with conical billiards. arXiv: 2508.02786v1 [nlin.CD]. Aug 4, 2025. 

https://arxiv.org/abs/2508.02786

Phys. Rev. E 112, 044221. Oct 21, 2025.

https://journals.aps.org/pre/abstract/10.1103/18f7-sqhz

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

Keywords: gst, billiards, conical billiard, chaos, transitions, neural networks

# aibot: Tensor Logic, a hypothesis for the next step in artificial intelligence.

<< ️Progress in AI is hindered by the lack of a programming language with all the requisite features. Libraries like PyTorch and TensorFlow provide automatic differentiation and efficient GPU implementation, but are additions to Python, which was never intended for AI. Their lack of support for automated reasoning and knowledge acquisition has led to a long and costly series of hacky attempts to tack them on. >>

<< ️On the other hand, AI languages like LISP and Prolog lack scalability and support for learning. This (AA) paper proposes tensor logic, a language that solves these problems by unifying neural and symbolic AI at a fundamental level. The sole construct in tensor logic is the tensor equation, based on the observation that logical rules and Einstein summation are essentially the same operation, and all else can be reduced to them. (AA) show how to elegantly implement key forms of neural, symbolic and statistical AI in tensor logic, including transformers, formal reasoning, kernel machines and graphical models. >>

<< ️Most importantly, tensor logic makes new directions possible, such as sound reasoning in embedding space. This combines the scalability and learnability of neural networks with the reliability and transparency of symbolic reasoning, and is potentially a basis for the wider adoption of AI. >>

Pedro Domingos. Tensor Logic: The Language of AI. arXiv: 2510.12269v3 [cs.AI]. Oct 16, 2025.

https://arxiv.org/abs/2510.12269

Also: Millie Marconi. 20ott25 https://x.com/Yesterday_work_/status/1980265546068402492 repost tgn0s937k https://x.com/tgn0s937k30472

Also: ai (artificial intell) (bot), analogy, in https://www.inkgmr.net/kwrds.html 

Keywords: ai, aibot, artificial intelligence, tensor logic, unifying neural- symbolic- statistical- AI.

# gst: gigantic dynamical spreading and anomalous diffusion of jerky active particles.

<< ️Jerky active particles are Brownian self-propelled particles which are dominated by “jerk,” the change in acceleration. They represent a generalization of inertial active particles. In order to describe jerky active particles, a linear jerk equation of motion which involves a third-order derivative in time, Stokes friction, and a spring force (AA) combined with activity modeled by an active Ornstein-Uhlenbeck process. This equation of motion (They) solved analytically and the associated mean-square displacement (MSD) is extracted as a function of time. >>

<< ️For small damping and small spring constants, the MSD shows an enormous superballistic spreading with different scaling regimes characterized by anomalous high dynamical exponents 6, 5, 4, or 3 arising from a competition among jerk, inertia, and activity. When exposed to a harmonic potential, the gigantic spreading tendency induced by jerk gives rise to an enormous increase of the kinetic temperature and even to a sharp localization-delocalization transition, i.e., a jerky particle can escape from harmonic confinement. >>

<< ️The transition can be either first or second order as a function of jerkiness. Finally (AA)  shown that self-propelled jerky particles governed by the basic equation of motion can be realized experimentally both in feedback-controlled macroscopic particles and in active colloids governed by friction with memory. >>

Hartmut Löwen. Gigantic dynamical spreading and anomalous diffusion of jerky active particles. Phys. Rev. E 112, 045412. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/976t-qry7

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

Keywords: gst, particles, colloids, self-propelled particles, active Brownian particles, Jerky active particles, jerkiness, transitions, superballistic spreading, escape.

# gst: triadic percolation on multilayer networks.

<< ️Triadic interactions are special types of higher-order interactions that occur when regulator nodes modulate the interactions between other two or more nodes. In presence of triadic interactions, a percolation process occurring on a single-layer network becomes a fully-fledged dynamical system, characterized by period-doubling and a route to chaos. >>

<< ️Here, (AA) generalize the model to multilayer networks and name it as the multilayer triadic percolation (MTP) model. (They) find a much richer dynamical behavior of the MTP model than its single-layer counterpart. MTP displays a Neimark-Sacker bifurcation, leading to oscillations of arbitrarily large period or pseudo-periodic oscillations. >>

<< Moreover, MTP admits period-two oscillations without negative regulatory interactions, whereas single-layer systems only display discontinuous hybrid transitions.  >> 

Hanlin Sun, Filippo Radicchi, Ginestra Bianconi. Triadic percolation on multilayer networks. arXiv: 2510.09341v1 [nlin.AO]. Oct 10, 2025.

https://arxiv.org/abs/2510.09341

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

Keywords: gst, network, chaos, 

percolation, multilayer triadic 

percolation, higher-order 

interactions, triadic interactions.

# gst: apropos of waves that escape trapping; on internal wave whispering gallery modes in channels and critical-slope wave attractors.

<< ️Internal waves are an important feature of stratified fluids, both in oceanic and lake basins and in other settings. Many works have been published on the generic feature of internal wave trapping onto planar wave attractors and super-attractors in 2D & 3D and the exceptional class of standing global internal wave modes. >>

<< ️However, most of these works did not deal with waves that escape trapping. By using continuous symmetries (AA) analytically prove the existence of internal wave Whispering Gallery Modes (WGMs), internal waves that propagate continuously without getting trapped by attractors. WGMs neutral stability with respect to different perturbations enable whispering gallery beams, a continuum of rays propagating together coherently. The systems' continuous symmetries also enable projection onto 2D planes that yield effective 2D billiards preserving the original dynamics. >>

<< ️By examining rays deviating from these WGMs in parabolic channels (They) discover a new type of wave attractor which is located along the channel instead of across it as in previous works. This new wave attractor leads to a re-understanding of WGMs as sitting at the border between the two basins of attraction. >>

<< ️Finally, both critical-slope wave attractors and whispering gallery beams are used to propose explanations for along-channel energy fluxes in submarine canyons and tidal energy intensification near critical slopes. >>

Nimrod Bratspiess, Eyal Heifetz, Leo R. M. Maas. On internal wave whispering gallery modes in channels and critical-slope wave attractors. arXiv: 2510.07218v1 [physics.flu-dyn]. Oct 8, 2025.

https://arxiv.org/abs/2510.07218

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

Keywords: gst, waves, internal waves, internal wave whispering gallery modes (WGMs), wave attractors, basins of attraction, billiards.

# gst: apropos of stochastic resetting, abrupt transitions in the optimization of diffusion with distributed resetting.

<< ️Brownian diffusion subject to stochastic resetting to a fixed position has been widely studied for applications to random search processes. In an unbounded domain, the mean first-passage time at a target site can be minimized for a convenient choice of the resetting rate. >>

<< ️Here (AA) study this optimization problem in one dimension when resetting occurs to random positions, chosen from a probability density function with compact support that does not include the target. Depending on the shape of this distribution, the optimal resetting rate either varies smoothly with the mean distance to the target, as in single-site resetting, or exhibits a discontinuity caused by the presence of a second local minimum in the mean first-passage time. These two regimes are separated by a critical line containing a singular point that (They) characterize through a Ginzburg-Landau theory. >>

<< ️To quantify how useful is a given resetting point for the search, (AA) calculate the probability density function of the last resetting position before absorption. The discontinuous transition separates two markedly different optimal strategies: one with a small resetting rate where the last path before absorption starts from a rather distant but likely position, while the other strategy has a large resetting rate, favoring last paths starting from not-so-likely points but which are closer to the target. >>

Pedro Julián-Salgado, Leonardo Dagdug, Denis Boyer. Abrupt transitions in the optimization of diffusion with distributed resetting. Phys. Rev. E 112, 044110. Oct 6, 2025.

https://journals.aps.org/pre/abstract/10.1103/b15f-47qw

arXiv: 2507.14483v2 [cond-mat.stat-mech]. Oct 7, 2025.

https://arxiv.org/abs/2507.14483

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

Keywords: gst, randomness, transitions, stochastic resetting, small-- large resetting rate.

# gst: effects of inertia on the asynchronous state of a disordered Kuramoto model.

<< ️(AA) investigate the role of inertia in the asynchronous state of a disordered Kuramoto model. (They) extend an iterative simulation scheme to the case of the Kuramoto model with inertia in order to determine the self-consistent fluctuation statistics, specifically, the power spectra of network noise and single oscillators. >>

<< ️Comparison with network simulations demonstrates that this works well whenever the system is in an asynchronous state. >>

 

 << ️(AA) also find an unexpected effect when varying the degree of inertia: the correlation time of the oscillators becomes minimal at an intermediate mass of the oscillators; correspondingly, the power spectra appear flatter and thus more similar to white noise around the same value of mass. (They) also find a similar effect for the Lyapunov spectra of the oscillators when the mass is varied. >>

Yagmur Kati, Ralf Toenjes, Benjamin Lindner. Effects of inertia on the asynchronous state of a disordered Kuramoto model. Phys. Rev. E 112, 044301. Oct 6, 2025.

https://journals.aps.org/pre/abstract/10.1103/xt4m-bkp8

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

Keywords: gst, networks, noise, order, disorder, fluctuations, inertia, asynchronous states, transitions, Kuramoto model.

# gst: predicting the response of structurally altered and asymmetrical networks.

<< ️(AA) investigate how the response of coupled dynamical systems is modified due to a structural alteration of the interaction. >>

<< ️The majority of the literature focuses on additive perturbations and symmetrical interaction networks. Here, (They) consider the challenging problem of multiplicative structural alterations and asymmetrical interaction coupling. >>

<< ️(AA) introduce a framework to approximate the averaged response at each network node for general structural alterations, including non-normal and asymmetrical ones. (Their) findings indicate that both the asymmetry and non-normality of the structural alterations impact the global and local responses at different orders in time. (They) propose a set of matrices to identify the nodes whose response is affected the most by the structural alteration. >>

Melvyn Tyloo. Predicting the response of structurally altered and asymmetrical networks. Phys. Rev. E 112, L042301. Oct 10, 2025. 

https://journals.aps.org/pre/abstract/10.1103/3s3d-qr4l

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

Keywords: gst, networks, disorder & fluctuations, transitions.

# gst: why and when merging surface nanobubbles jump.

<< Gas bubble accumulation on substrates reduces the efficiency of many physicochemical processes, such as water electrolysis. For microbubbles, where buoyancy is negligible, coalescence-induced jumping driven by the release of surface energy provides an efficient pathway for their early detachment. >>

<< At the nanoscale, however, gas compressibility breaks volume conservation during coalescence, suppressing surface energy release and seemingly disabling this detachment route. >>

<< Using molecular dynamics simulations, continuum numerical simulations, and theoretical analysis, (AA) show that surface nanobubbles with sufficiently large contact angles can nevertheless detach after coalescence. In this regime, detachment is powered by the release of pressure energy associated with nanobubble volume expansion. This (AA) finding thus establishes a unified driving mechanism for coalescence-induced bubble detachment across all length scales. >>

Yixin Zhang, Xiangyu Zhang, Detlef Lohse. Why and when merging surface nanobubbles jump. arXiv: 2509.22934v1 [cond-mat.soft]. Sep 26, 2025.

https://arxiv.org/abs/2509.22934

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

Keywords: gst, bubbles, surface nanobubbles, surface energy release, coalescence, coalescence-induced jumping, coalescence-induced bubble detachment.

# gst: random trajectories in bounded domains

<< ️Can we deduce the total length of a random trajectory by observing only its local path segments within a confined domain? Surprisingly, the answer is yes—for curves randomly placed and oriented in space, whether stochastic or deterministic; generated by ballistic or diffusive dynamics; possibly interrupted by stopping or branching; and in two or more dimensions. More precisely, the mean total length ⟨𝐿⟩ relates to the mean in-domain path length ⟨ℓ⟩ and the mean chord length of the domain ⟨𝜎⟩ via the following simple and universal relation:

              1/⟨ℓ⟩ = 1/⟨𝐿⟩ + 1/⟨𝜎⟩

Here, ⟨𝜎⟩ is a purely geometric quantity, dependent only on the volume-to-surface ratio of the domain. Derived solely from the kinematic formula of integral geometry, the result is independent of step-length statistics, memory, absorption, and branching, making it equally relevant to photons in turbid tissue, active bacteria in microchannels, cosmic rays in molecular clouds, or neutron chains in nuclear reactors. Monte Carlo simulations spanning straight needles, Y shapes, and isotropic random walks in two and and three dimensions confirm the universality and demonstrate how a local measurement of ⟨ℓ⟩ yields ⟨𝐿⟩ without ever tracking the full trajectory. >>

T. Binzoni, E. Dumonteil, A. Mazzolo. Universal property of random trajectories in bounded domains. Phys. Rev. E 112, 044105. Oct 3, 2025.

https://journals.aps.org/pre/abstract/10.1103/dng6-9519

arXiv: 2011.06343v3 [math-ph]. May 16, 2025. 

https://arxiv.org/abs/2011.06343

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

Also: voli a casaccio (quasi-stochastic poetry). Oct 01, 2006.

https://inkpi.blogspot.com/2006/10/2066-voli-casaccio.html

Keywords: gst, randomness, random trajectories,  walk, random walk, bounded domains.