Translate

Visualizzazione dei post in ordine di data per la query gst. Ordina per pertinenza Mostra tutti i post
Visualizzazione dei post in ordine di data per la query gst. Ordina per pertinenza Mostra tutti i post

mercoledì 18 marzo 2026

# gst: geometry of contraction-induced flows.


<< ️Peristalsis is the driving mechanism behind a broad array of biological and engineered flows. In peristaltic pumping, a wavelike contraction of the tube wall produces local changes in volume which induce flow. Net flow arises due to geometric nonlinearities in the momentum equation, which must be properly captured to compute the flow accurately. >>

<< ️While most previous models focus on radius-imposed peristalsis, they often neglect longitudinal length changes—a natural consequence of radial contraction in elastic materials. In this paper, to capture a more accurate picture of peristaltic pumping, (AA) calculate the flow in an elastic vessel undergoing contractions in the transverse and longitudinal directions simultaneously, keeping the geometric nonlinearities arising in the strain. >>

<< ️(They) demonstrate that transverse and longitudinal contractions induce instantaneous flows at the same order in wall strain but in opposite directions. (They) investigate the influence of the wall's Poisson ratio on the flow profile. Incompressible walls suppress flow by minimizing local volume changes, whereas auxetic walls enhance flow. For radius-imposed peristaltic waves, wall incompressibility reduces both reflux and particle trapping. In contrast, length-imposed waves typically generate backflow, although trapping can still occur at large amplitudes for some Poisson ratios. >>

Aaron Winn, Eleni Katifori. Geometry of contraction-induced flows. Phys. Rev. Fluids 11, 033101. Mar 12, 2026.

arXiv: 2510.24016v1 [physics.flu-dyn]. Oct 28, 2025.

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

Keywords: gst, waves, elasticity, networks, peristalsis, peristaltic pumping, peristaltic waves, wavelike contractions, transverse and longitudinal contractions, longitudinal length changes, instantaneous flows, auxetic walls, backflows.

martedì 17 marzo 2026

# gst: from fluttering to drifting: inertialess sedimentation of an achiral particle.


<< ️There has been much recent interest in the chiral motion of achiral particles that sediment in a viscous fluid in a regime where inertial effects can be neglected. This occurs in a broad range of applications such as those involving biological objects like algae, ultrathin graphene flakes, or colloidal suspensions. It is known that particles with two planes of symmetry can be categorized as “settlers,” “drifters,” or “flutterers,” where the latter sediment along chiral trajectories despite their achiral shapes. >>

<< ️Previous work investigated the sedimentation of circular disks bent into a U-shape and identified them as “flutterers.” In this work (AA) analyze the change in behavior of such particles when (They) break one of their symmetries by pinching the disks isometrically along their axis, a shape change that can arise during the sedimentation of thin elastic sheets. The “fluttering” behavior is found to be robust to such shape changes, with the trajectories now evolving toward helical paths. However, the behavior changes when the degree of pinching becomes too strong, at which point the particles become “drifters” which sediment steadily without rotation. >>

<< ️(AA) establish criteria for the transition between the two types of behavior and confirm (Their) predictions in experiments. Finally, (AA) discuss the implications of (Their) observations for the dispersion of dilute suspensions made of such particles. >>

Christian Vaquero-Stainer, Tymoteusz Miara, Anne Juel, et al. From fluttering to drifting: Inertialess sedimentation of an achiral particle. Phys. Rev. Fluids 11, 034102. March 10, 2026.


Keywords: gst, behaviors, particles, achiral particles, settlers, drifters, flutterers.

sabato 14 marzo 2026

# gst: prolate and oblate nematic shells under equal and hybrid alignments.

<< ️Using the Landau–de Gennes free-energy formalism with the fast inertial relaxation engine relaxation method, (AA) investigate the role of geometry and anchoring conditions in nematic liquid crystal shells. Both prolate and oblate geometries are explored for four distinct anchoring configurations: degenerate planar on both surfaces, homeotropic on both surfaces, and hybrid cases with planar-homeotropic and homeotropic-planar alignments. (Their) simulations reveal a rich variety of topological defect arrangements, including bipolar configurations with boojums; tetrahedral patterns featuring disclination lines, boojums, and hedgehogs; Saturn-ring structures; and twisted director fields in the equatorial plane. >>

<< ️Detailed energy analyses demonstrate that elastic distortions—splay, bend, and twist—are strongly influenced by parameters such as inner and outer radii, shell thickness, and aspect ratio, which in turn dictate the stabilization of specific defect structures. ️These findings provide insights into the curvature-driven mechanisms that control the formation of defects in nematic shells. >>

F. C. Cruz, E. K. Lenzi, Q. Li, et al. Prolate and oblate nematic shells under equal and hybrid alignments. Phys. Rev. E 113, 035403. Mar 4, 2026.

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

Keywords: gst, spheroids, elasticity, nematic liquid crystal shells, prolate and oblate geometries, topological defects, elastic distortions, curvature-driven mechanisms.

venerdì 13 marzo 2026

# gst: predicting oscillations in complex networks with delayed feedback.


<< ️Oscillatory dynamics are common features of complex networks, often playing essential roles in regulating function. Across scales from gene regulatory networks to ecosystems, delayed feedback mechanisms are key drivers of system-scale oscillations. >> 

<< ️The analysis and prediction of such dynamics are highly challenging, however, due to the combination of high-dimensionality, non-linearity and delay. Here, (AA) systematically investigate how structural complexity and delayed feedback jointly induce oscillatory dynamics in complex systems, and introduce an analytic framework comprising theoretical dimension reduction and data-driven prediction. >>

<< ️(They) reveal that oscillations emerge from the interplay of structural complexity and delay, with reduced models uncovering their critical thresholds and showing that greater connectivity lowers the delay required for their onset. (Their) theory is empirically tested in an experiment on a programmable electronic circuit, where oscillations are observed once structural complexity and feedback delay exceeded the critical thresholds predicted by our theory. >>

<< ️Finally, (They) deploy a reservoir computing pipeline to accurately predict the onset of oscillations directly from timeseries data. (AA) findings deepen understanding of oscillatory regulation and offer new avenues for predicting dynamics in complex networks. >>

Shijie Liu, Jinliang Han, Jianming Liu, et al. Predicting oscillations in complex networks with delayed feedback. arXiv: 2603.04251v2 [cond-mat.dis-nn]. Mar 4, 2026.


Keywords: gst, networks, oscillatory dynamics, oscillatory regulations, system-scale oscillations, delay, delayed feedback mechanisms, criticality, critical thresholds.

mercoledì 11 marzo 2026

# gst: localization of information driven by stochastic resetting.


<< ️The dynamics of extended many-body systems are generically chaotic. Classically, a hallmark of chaos is the exponential sensitivity to initial conditions captured by positive Lyapunov exponents. Supplementing chaotic dynamics with stochastic resetting drives a sharp dynamical phase transition: (AA) show that the Lyapunov spectrum, i.e., the complete set of Lyapunov exponents, abruptly collapses to zero above a critical resetting rate. >>

<< ️At criticality, (They) find a sudden loss of analyticity of the velocity-dependent Lyapunov exponent, which (They) relate to the transition from ballistic scrambling of information to an arrested regime where information becomes exponentially localized over a characteristic length diverging at criticality with an exponent 𝜈=1/2 and a dynamical exponent 𝑧=2. (They) illustrate (Their) analytical results on generic chaotic dynamics by numerical simulations of coupled map lattices. >>

Camille Aron, Manas Kulkarni. Localization of information driven by stochastic resetting. Phys. Rev. E 113, L022101. Feb 23, 2026.

arXiv:2510.07394v2 [cond-mat.stat-mech]. Feb 24, 2026.

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

Keywords: gst, chaos, transition, collapse, randomness, stochasticity, stochastic resetting, phase transition, criticality, critical resetting rate, ballistic scrambling of information.

sabato 7 marzo 2026

# brain: collective dynamics in spiking neural networks beyond Dale's principle.


<< ️Dale's Principle has historically guided neuroscience research as a valuable rule of thumb, namely that all synapses on each neuron release the same set of neurotransmitters. Most existing Spiking Neuron Network models share this dichotomous assumption that neurons are either excitatory or inhibitory; however, recent experimental evidence points towards co-release mechanisms that violate this assumption. >>

<< ️Here, (AA) introduce a minimal model of "Bilingual" neurons violating Dale's principle that can exert both excitatory and inhibitory effects. (They) identify parameter regimes in which this architecture exhibits transitions between synchronous and asynchronous dynamics that differ quantitatively from those observed in a matched monolingual control architecture. >>

<< ️(AA) report distinct information-processing signatures both at the level of neurons and higher-order interactions between them near the phase transitions. These (AA) results suggest that the population of neurons violating Dale's principle may provide an alternative mechanism for regulating large-scale oscillatory activity in neural circuits. >>

Ross Ah-Weng, Hardik Rajpal. Collective Dynamics in Spiking Neural Networks Beyond Dale's Principle. arXiv: 2602.23202v1 [q-bio.NC]. Feb 26, 2026.

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

Keywords: gst, brain, neuro, networks, transitions, neural circuits, spiking neuron networks, excitatory and inhibitory effects, Dale's principle, Henry Hallett Dale, bilingual neurons, transitions between synchronous and asynchronous dynamics.

giovedì 5 marzo 2026

# gst: multi-ring necklace vortex solitons in Kerr nonlinear media with azimuthally modulated Bessel potentials.


<< ️(AA) address the existence, stability, and dynamics of single-ring and multi-ring vorticity-carrying necklace solitons under the action of the Kerr nonlinearity and a Bessel-lattice potential modulated in the azimuthal direction. The model may be realized in the spatial domain for bulk optical waveguides, the spatiotemporal domain for optical cavities, and for effectively two-dimensional Bose-Einstein condensates. The setup supports single- and multi-ring necklace vortex patterns, including monopoles, dipoles, tripoles, quadrupoles, pentapoles, sextupoles, octupoles, and 12-poles. >>

<< ️In contrast with the inherent instability of conventional vortex beams with high topological charges (winding numbers), vortex necklace-shaped solitons with large winding numbers are found to be stable in the present setup. In particular, octupoles exhibit stable breathing dynamics, and 12-pole necklaces with high winding numbers may be stable. >>

<< ️These (AA) findings provide a new way for generating stable vortex necklaces, offering a vast potential for manipulations of complex spatiotemporal light fields. >>

Ruolan Zhao, Jing Chen, Boris A. Malomed, et al. Multi-ring necklace vortex solitons in Kerr nonlinear media with azimuthally modulated Bessel potentials. arXiv: 2602.18703v1 [physics.optics]. Feb 21, 2026.

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

Keywords: gst, vortex, solitons, vortex necklace-shaped solitons, single-ring vorticity, multi-ring vorticity, stable vortex necklace, transitions.

mercoledì 4 marzo 2026

# gst: superflows around corners.


<< ️(AA) investigate analytically and numerically the dynamics of a two-dimensional superflow governed by the Gross-Pitaevskii equation passing over finite-size rectangular obstacles: an impenetrable wall and an impenetrable rectangular well. Extending classical studies of vortex nucleation around smooth obstacles, (They) focus on the role of sharp corners in determining the onset of vortex nucleation. Using a combination of analytical techniques based on the Schwarz-Christoffel methods for potential flow and on numerical simulations, (They) show that local velocity amplification near sharp corners crucially controls the critical flow velocity for vortex nucleation. >>

<< ️For both wall and well configurations, (They) identify analytically and theoretically the critical velocities as a function of the obstacle width and its height or depth, finding an excellent agreement between the theory and (Their) numerical simulations. (Their) results provide a simple framework for understanding superflow stability past finite-size obstacles with sharp features and are directly relevant to experimentally realizable configurations in atomic Bose-Einstein condensates and related superfluid systems. >>

Thomas Frisch, Christophe Josserand, Sergio Rica. Superflows around corners. arXiv: 2602.18876v1 [cond-mat.quant-gas]. Feb 21, 2026.


Keywords: gst, vorticity, vortex nucleation, two-dimensional superflow, superflow stability, smooth obstacles, sharp corners. 

lunedì 2 marzo 2026

# gst: a phase description of mutually coupled chaotic oscillators.


<< ️The synchronization of rhythms is ubiquitous in both natural and engineered systems, and the demand for data-driven analysis is growing. When rhythms arise from limit cycles, phase reduction theory shows that their dynamics are universally modeled as coupled phase oscillators under weak coupling. This simple representation enables direct inference of inter-rhythm coupling functions from measured time-series data. >>

<< ️However, strongly rhythmic chaos can masquerade as noisy limit cycles. In such cases, standard estimators still return plausible coupling functions even though a phase-oscillator model lacks a priori justification. >>

<< ️(AA) therefore extend the phase description to the chaotic oscillators. Specifically, (They) derive a closed equation for the phase difference by defining the phase on a Poincaré section and averaging the phase dynamics over invariant measures of the induced return maps. Numerically, the derived theoretical functions are in close agreement with those inferred from time-series data. Consequently, (Their) results justify the applicability of phase description to coupled chaotic oscillators and show that data-driven coupling functions retain clear dynamical meaning in the absence of limit cycles. >>

Haruma Furukawa, Takashi Imai, Toshio Aoyagi. A Phase Description of Mutually Coupled Chaotic Oscillators. arXiv: 2602.17519v1 [nlin.CD]. Feb 19, 2026.

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

Keywords: gst, chaos, synchronization of rhythms, limit cycles, noisy limit cycles, coupled phase oscillators, transitions.

sabato 28 febbraio 2026

# gst: spatiotemporal noise stabilizes unbounded diversity in strongly-competitive communities.


<< ️Classical ecological models predict that large, diverse communities should be unstable, presenting a central challenge to explaining the stable biodiversity seen in nature. (AA) revisit this long-standing problem by extending the generalized Lotka-Volterra model to include both spatial structure and environmental fluctuations across space and time.  >>

<< ️(They) find that neither space nor environmental noise alone can resolve the tension between diversity and stability, but that their combined effects permit arbitrarily many species to stably coexist despite strongly disordered competitive interactions. (They) analytically characterize the noise-induced transition to coexistence, showing that spatiotemporal noise drives an anomalous scaling of abundance fluctuations, known empirically as Taylor's law. >>

<< ️At the community level, this manifests as an effective sublinear self-inhibition that renders the community stable and asymptotically neutral in the high-diversity limit. Spatiotemporal noise thus provides a novel resolution to the diversity-stability paradox and a generic mechanism by which complex communities can persist. >>

Amer Al-Hiyasat, Daniel W. Swartz, Jeff Gore, et al. Spatiotemporal noise stabilizes unbounded diversity in strongly-competitive communities. arXiv: 2602.13423v1 [q-bio.PE]. Feb 13, 2026.

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

Keywords: gst, noise, spatiotemporal noise, disorder, transition, noise-induced transition, disordered competitive interactions, spatial structure and environmental fluctuations.

mercoledì 25 febbraio 2026

# gst: dynamics of perturbed elliptical billiard tables.


<< ️Dynamical billiards consist of a particle on a two-dimensional table, bouncing elastically off a boundary curve. The state of the system is given by two numbers: one describing the location along the curve where the bounce occurs, and another describing the incoming angle of the bounce. Successive bounces define a two-dimensional area preserving map, and iterating this map gives a dynamical system first studied by Birkhoff. >>

<< ️One of the simplest smooth table shapes is that of an ellipse, in which case the dynamics of the billiard map is completely integrable. The longstanding Birkhoff conjecture is that elliptical tables are the only smooth convex table for which complete integrability occurs. >>

<< ️In this spirit, (AA) present an implicit real analytic method for iterating billiard maps on perturbed elliptical tables. This method allows (They) to compute local stable and unstable manifolds of periodic orbits using the parameterization method. Globalizing these local manifolds numerically provides insight into the dynamics of the table. >>

Patrick Bishop, Summer Chenoweth, Emmanuel Fleurantin, et al. Dynamics of perturbed elliptical billiard tables. arXiv: 2602.15272v1 [math.DS]. Feb 17, 2026.

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

Keywords: gst, billiard, particles, bouncing, elasticity, perturbed elliptical table.

lunedì 23 febbraio 2026

# gst: steady states in a model of opposing local and nonlocal hops.

<< ️(AA) study a one-dimensional lattice model of particles following hard-core exclusion and performing opposing local and nonlocal moves with probability 𝑝 and 1−𝑝, respectively. (Their) model shows the interesting feature that the direction of the particle current can be switched by simply changing the density 𝜌 of particles on the lattice. (They) study the dependence of current on 𝑝 as well as 𝜌 and present the separation of positive and negative current regions on a 𝑝−𝜌 plane. >>

<< ️Further, (They) study the effect of disorder on this model by introducing a single site with valvelike dynamics. The site allows only unidirectional, local outward motion with rate 𝑟. The interplay of the disorder strength 𝑟, particle density 𝜌, and probability 𝑝 leads to a rich possibility with four different kinds of shock phases in the steady state. >>

<< ️(They) study the shock densities using Monte Carlo simulations and mean field calculations. While (Their) mean field treatment describes the numerical results quite well qualitatively, (AA) see certain quantitative deviations. (They) try to understand these deviations using measures of correlation in the system and provide heuristic arguments for the mismatch. >>

Ankur Mishra, Apoorva Nagar. Steady states in a model of opposing local and nonlocal hops. Phys. Rev. E 113, 024113. Feb 10, 2026.

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

Keywords: gst, particles, disorder, phase transitions, shock phases, valvelike dynamics.

sabato 21 febbraio 2026

# gst: phase-controlled elastic, inelastic, and coalescent collisions of two-dimensional flat-top solitons.

<< ️(AA) investigate elastic, inelastic, and coalescent collisions between two-dimensional flat-top solitons supported by the cubic-quintic nonlinear Schrödinger equation. Numerical simulations reveal distinct collision regimes ranging from nearly elastic scattering to strongly inelastic interactions leading to long-lived merged states. >>

<< ️(They) demonstrate that the transition between these regimes is primarily controlled by the relative phase of the solitons at the collision point, with out-of-phase collisions suppressing overlap and in-phase collisions promoting strong interaction. >>

<< ️Kinetic-energy diagnostics are introduced to quantitatively characterize collision outcomes and to identify phase- and separation-dependent windows of elasticity. To interpret the observed dynamics, (They) extract effective phase-dependent interaction potentials from collision trajectories, providing a mechanical picture of attraction and repulsion between flat-top solitons. The stability of merged states formed after strongly inelastic collisions is explained by their lower energetic cost, arising from interfacial energetics, where a balance between internal pressure and edge tension plays a central role. A variational analysis based on direct energy minimization supports this picture by revealing robust energetic minima associated with stationary two-dimensional flat-top solitons. >>

M. O. D. Alotaibi, Y. O. A. Abughnheim, L. Al Sakkaf, et al. Phase-controlled elastic, inelastic, and coalescent collisions of two-dimensional flat-top solitons. arXiv: 2602.07762v1 [nlin.PS]. Feb 8, 2026.

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

Keywords: gst, soliton, transitions, elastic, inelastic, and coalescent collisions, elastic scattering interactions, strongly inelastic interactions, long-lived merged states, attraction, repulsion, internal pressure, edge tension.

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.

mercoledì 18 febbraio 2026

# gst: dynamics of small bubbles in turbulence in non-dilute conditions.


<< Turbulent flows laden with small bubbles are ubiquitous in many natural and industrial environments. From the point of view of numerical modeling, to be able to handle a very large number of small bubbles in direct numerical simulations, one traditionally relies on the one-way coupling paradigm. There, bubbles are passively advected and are noninteracting, implicitly assuming dilute conditions. >>

<< Here, (AA) study bubbles that are four-way coupled, where both the feedback on the fluid and excluded-volume interactions between bubbles are taken into account. (They) find that, while the back reaction from the bubble phase onto the fluid phase remains energetically small under most circumstances, the excluded-volume interactions between bubbles can have a significant influence on the Lagrangian statistics of the bubble dynamics. (They) show that as the volume fraction of bubbles increases, the preferential concentration of bubbles in filamentary high-vorticity regions decreases as these strong vortical structures get filled up; this happens at a volume fraction of around one percent for Re𝜆=𝒪⁡(10^2). >>

<< (AA) furthermore study the influence on the Lagrangian velocity-structure function as well as pair dispersion, and find that, while the mean dispersive behavior remains close to that obtained from one-way coupling simulations, some evident signatures of bubble collisions can be retrieved from the structure functions and the distribution of the dispersion, even at very small volume fractions. >>

Xander M. de Wit, Hessel J. Adelerhof, André Freitas, et al. Dynamics of small bubbles in turbulence in non-dilute conditions. Phys. Rev. Fluids 11, 024602. Feb 5, 2026.

arXiv: 2510.03968v2 [physics.flu-dyn]. Jan 29, 2026.

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

Keywords: gst, bubble, bubble dynamics, bubble collisions, turbulence, one-way coupling, four-way coupling.

sabato 14 febbraio 2026

# gst: spatial self-organization driven by temporal noise.

<< ️The counterintuitive emergence of order from noise is a central phenomenon in science, ranging from pattern formation and synchronization to order-by-disorder in frustrated systems. While large-scale spatial self-organization induced by local spatial noise is well studied, whether temporal noise can also drive such organization remains an open question. >>

<< ️Here, by studying interacting particle systems, (AA) show that temporally correlated noise can lead to a self-organized state with suppressed long-range density fluctuations, or hyperuniformity. Further, (They) develop a fluctuating hydrodynamic theory that quantitatively explains the origin of this phenomenon. >>

<< ️Finally, by casting the dynamics as a stochastic optimization problem, (They) show that temporal correlations lead to better solutions, akin to perturbed gradient descent in neural networks -- where noise is injected during training to escape poor minima. This reveals a striking correspondence between perturbed gradient descent dynamics on the energy landscapes of particle systems and the loss landscapes of neural networks. >>

Satyam Anand, Guanming Zhang, Stefano Martiniani. Spatial self-organization driven by temporal noise. arXiv: 2601.23098v1 [cond-mat.soft]. Jan 30, 2026.

Also: self-assembly, noise, order, disorder, disorder & fluctuations, particle, escape, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, self-assembly, noise, order, disorder, disorder & fluctuations, particles, networks, neural networks, spatial noise, temporal noise, noise-driven self-organization.

martedì 10 febbraio 2026

# gst: rising bubbles draw surface patterns.


<< ️Small bubbles rising in a chain can self-organize into regular patterns upon reaching a liquid's free surface. This phenomenon is investigated (by AA) through direct numerical simulations. By varying the bubble release period, distinct branching patterns characterized by different numbers of arms are observed. These macroscopic patterns are found to stem from localized interactions between the bubbles, the free surface, and the surrounding liquid flow. >>

<< A heuristic model is proposed that quantitatively relates the number of arms to the bubble release period and predicts the probability of observing specific arm counts. This (AA) study provides insights into broader nonlinear pattern formation and self-organization phenomena. >>

Dabao Li, Lang Qin, Zhigang Zuo, et al. Rising bubbles draw surface patterns: A numerical study. Phys. Rev. Fluids 11, 023602. Feb 6, 2026.

arXiv: 2509.01315v2 [physics.flu-dyn]. Jan 27, 2026.

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

Keywords: gst, bubble, self-assembly, branching patterns.

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.