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

venerdì 2 maggio 2025

# gst: period-doubling route to chaos in viscoelastic flows

<< Polymer solutions can develop chaotic flows, even at low inertia. This purely elastic turbulence is well studied, but little is known about the transition to chaos. In two-dimensional (2D) channel flow and parallel shear flow, traveling wave solutions involving coherent structures are present for sufficiently large fluid elasticity. >>

AA << numerically study 2D periodic parallel shear flow in viscoelastic fluids, and (They) show that these traveling waves become oscillatory and undergo a series of period-doubling bifurcations en-route to chaos. >>

Jeffrey Nichols, Robert D. Guy, Becca Thomases. Period-doubling route to chaos in viscoelastic Kolmogorov flow. Phys. Rev. Fluids 10, L041301. Apr 17, 2025.

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

Keywords: gst, chaos, waves, traveling waves, elasticity, viscoelastic fluids, turbulence, elastic turbulence, period-doubling bifurcations, transitions

martedì 22 aprile 2025

# gst: strange attractors in complex networks

<< Disorder and noise in physical systems often disrupt spatial and temporal regularity, yet chaotic systems reveal how order can emerge from unpredictable behavior. Complex networks, spatial analogs of chaos, exhibit disordered, non-Euclidean architectures with hidden symmetries, hinting at spontaneous order. Finding low-dimensional embeddings that reveal network patterns and link them to dimensionality that governs universal behavior remains a fundamental open challenge, as it needs to bridge the gap between microscopic disorder and macroscopic regularities. >>

<< Here, the minimal space revealing key network properties is introduced, showing that non-integer dimensions produce chaotic-like attractors. >>

Pablo Villegas. Strange attractors in complex networks. Phys. Rev. E 111, L042301. Apr 15, 2025. 

arXiv: 2504.08629v1 [cond-mat.stat-mech] . Apr 11, 2025.

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

Keywords: gst, disorder, disorder & fluctuations, noise, networks, attractors, self-similarity, chaos 

venerdì 18 aprile 2025

# gst: weird quasiperiodic attractors


AA << consider a class of n-dimensional, n≥2, piecewise linear discontinuous maps that can exhibit a new type of attractor, called a weird quasiperiodic attractor. While the dynamics associated with these attractors may appear chaotic, (They)  prove that chaos cannot occur. The considered class of n-dimensional maps allows for any finite number of partitions, separated by various types of discontinuity sets. The key characteristic, beyond discontinuity, is that all functions defining the map have the same real fixed point. These maps cannot have hyperbolic cycles other than the fixed point itself. >>

Laura Gardini, Davide Radi, et al. Abundance of weird quasiperiodic attractors in piecewise linear discontinuous maps. arXiv: 2504.04778v1 [math.DS]. Apr 7, 2025.

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

Keywords: gst, attractors, weird attractors, chaos


sabato 12 aprile 2025

# gst: chaotic and time-periodic edge states in square duct flow.


AA << analyse the dynamics within the stability boundary between laminar and turbulent square duct flow with the aid of an edge-tracking algorithm. As for the circular pipe, the edge state turns out to be a chaotic attractor within the edge if the flow is not constrained to a symmetric subspace. The chaotic edge state dynamics is characterised by a sequence of alternating quiescent phases and regularly occurring bursting episodes. These latter reflect the different stages of the well-known streak-vortex interaction in near-wall turbulence: the edge states feature most of the time a single streak with a number of flanking quasi-streamwise vortices attached to one of the four surrounding walls. The initially straight streak undergoes the classical linear instability and eventually breaks in an intense bursting event due to the action of the quasi-streamwise vortices. At the same time, the vortices give rise to a new generation of low-speed streaks at one of the neighbouring walls, thereby causing the turbulent activity to `switch' from one wall to the other. >>

<< When restricting the edge dynamics to a single or twofold mirror-symmetric subspace, on the other hand, the outlined bursting and wall-switching episodes become self-recurrent in time. These edge states thus represent the first periodic orbits found in the square duct. In contrast to the chaotic edge states in the non-symmetric case, the imposed symmetries enforce analogue bursting cycles to simultaneously appear at two parallel opposing walls in a mirror-symmetric configuration. Both localisation of the turbulent activity to one or two walls and wall switching are shown to be a common phenomenon in low Reynolds number duct turbulence. (They) therefore argue that the marginally turbulent trajectories transiently visit the identified edge states during these episodes, so that the edge states become actively involved in the turbulent dynamics. >>️

Markus Scherer, Markus Uhlmann, Genta Kawahara. Chaotic and time-periodic edge states in square duct flow. arXiv: 2503.22519v1 [physics.flu-dyn]. Mar 28, 2025️. 

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

Keywords: gst, turbulence, duct turbulence, chaos, chaotic edge states, vortex, instability, wall-switching episodes, bursting cycles 

martedì 1 aprile 2025

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


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

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

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

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

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

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

lunedì 31 marzo 2025

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


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

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

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

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

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

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

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

sabato 29 marzo 2025

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

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

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

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

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

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

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

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

sabato 8 marzo 2025

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

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

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

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

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

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


sabato 22 febbraio 2025

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

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

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

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

Their << findings indicate that quasi-periodic leapfrogging and chaotic interactions generally occur when the three vortex pairs have similar strengths and initial sizes. Conversely, discrepancies in these parameters cause the system to disintegrate into two subsystems: a single propagating vortex pair and two periodically leapfrogging pairs. >>️
Christiana Mavroyiakoumou, Wenzheng Shi. Order and Chaos in Systems of Coaxial Vortex Pairs. arXiv: 2502.07002v1 [physics.flu-dyn]. Feb 10, 2025. ️

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

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


mercoledì 19 febbraio 2025

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


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

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

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

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

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

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

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


mercoledì 12 febbraio 2025

# gst: chaotic billiards inside mixed curvatures


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

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

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

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

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

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

Keywords: gst, billiard, chaos


mercoledì 5 febbraio 2025

# gst: discontinuous transitions to active nematic turbulence.


<< Active fluids exhibit chaotic flows at low Reynolds number known as active turbulence. Whereas the statistical properties of the chaotic flows are increasingly well understood, the nature of the transition from laminar to turbulent flows as activity increases remains unclear. Here, through simulations of a minimal model of unbounded active nematics, (AA) find that the transition to active turbulence is discontinuous. (They) show that the transition features a jump in the mean-squared velocity, as well as bistability and hysteresis between laminar and chaotic flows. >>

<< From distributions of finite-time Lyapunov exponents, (AA) identify the transition at a value A∗≈4900 of the dimensionless activity number. Below the transition to chaos, (They) find subcritical bifurcations that feature bistability of different laminar patterns. These bifurcations give rise to oscillations and to chaotic transients, which become very long close to the transition to turbulence. Overall, (Their) findings contrast with the continuous transition to turbulence in channel confinement, where turbulent puffs emerge within a laminar background. >>

AA << propose that, without confinement, the long-range hydrodynamic interactions of Stokes flow suppress the spatial coexistence of different flow states, and thus render the transition discontinuous. >>️

Malcolm Hillebrand, Ricard Alert. Discontinuous Transition to Active Nematic Turbulence. arXiv: 2501.06085v1 [cond-mat.soft]. Jan 10, 2025.

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

Keywords: gst, chaos, transition, turbulence, jumps, active nematics


lunedì 3 febbraio 2025

# gst: limit cycles and chaos in planar hybrid systems.

<< The main inspiration of (this AA) work is the paper of Llibre and Teixeira (Nonlinear Dyn. 91, No. 1, 249-255, 2018) about Filippov systems formed by two linear centers and having x = 0 as discontinuity line. One of the main conclusions of the paper is that such systems cannot have limit cycles. Actually, either it does not have periodic orbits or every orbit is periodic. Therefore, its dynamics is relatively simple. Inspired by this work and the raising notion of hybrid systems, (AA) wondered what could happen if we allow jumps on the discontinuity line. As a result, (They) discovered not only that limit cycles are allowed with arbitrarily small “perturbations” in the jump, (..), but also that such systems allow chaotic dynamics. Therefore, (AA) conclude that hybrid systems with simple formulation can have rich dynamics. (They) also observe that a complete characterization of the dynamics of X ∈ Xn depends on the characterization of its first return map, which is a piecewise polynomial map on the real line. This, together with the fact that the systems studied here are a generalization of the Filippov systems (..), illustrates that hybrid systems can be seen as a three-fold bridge connecting continuous, piecewise continuous and discrete dynamical systems. >>️

Jaume Llibre, Paulo Santana. Limit cycles and chaos in planar hybrid systems. arXiv: 2407.05151v2 [math.DS]. Oct 1, 2024. 

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

Keywords: gst, limit cycles, chaos, transitions, small perturbations, jumps  


sabato 1 febbraio 2025

# gst: instability, shocks, and competition interfaces in the Brownian last-passage percolation model


<<  For stochastic Hamilton-Jacobi (SHJ) equations, instability points are the space-time locations where two eternal solutions with the same asymptotic velocity differ. Another crucial structure in such equations is shocks, which are the space-time locations where the velocity field is discontinuous. >>

AA << provide a detailed analysis of the structure and relationships between shocks, instability, and competition interfaces in the Brownian last-passage percolation model, which serves as a prototype of a semi-discrete inviscid stochastic HJ equation in one space dimension. >>

AA << show that the shock trees of the two unstable eternal solutions differ within the instability region and align outside of it. Furthermore, (They) demonstrate that one can reconstruct a skeleton of the instability region from these two shock trees. >>️

Firas Rassoul-Agha, Mikhail Sweeney. Shocks and instability in Brownian last-passage percolation. arXiv:  2407.07866v2 [math.PR]. Oct 18, 2024. 

Also: Brownian last-passage percolation (LPP) model. In: S. GANGULY,  A. HAMMOND. Stability and chaos in dynamical last passage percolation. Jun 7, 2024. 

Keywords: gst, instability, shock, competition, chaos, percolation


giovedì 16 gennaio 2025

# gst: chaotic dynamics creates and destroys branched flow.

<< The phenomenon of branched flow, visualized as a chaotic arborescent pattern of propagating particles, waves, or rays, has been identified in disparate physical systems ranging from electrons to tsunamis, with periodic systems only recently being added to this list. >>

Here, AA << explore the laws governing the evolution of the branches in periodic potentials. On one hand, (They) observe that branch formation follows a similar pattern in all nonintegrable potentials, no matter whether the potentials are periodic or completely irregular. Chaotic dynamics ultimately drives the birth of the branches. >>

<< On the other hand, (AA) results reveal that for periodic potentials the decay of the branches exhibits new characteristics due to the presence of infinitely stable branches known as superwires. Again, the interplay between branched flow and superwires is deeply connected to Hamiltonian chaos. >>

Alexandre Wagemakers, Aleksi Hartikainen, et al. Chaotic dynamics creates and destroys branched flow. Phys. Rev. E 111, 014214. Jan 7, 2025.
arXiv: 2406.12922v2 [nlin.PS]. 

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

Keywords: gst, chaos, waves, branched flows, superwires, transitions


venerdì 27 dicembre 2024

# gst: chimera states in a system of stationary and flying-through deterministic particles with an internal degree of freedom.

<< This work greatly extends (AA)  understanding of the dynamics of flying-through oscillators in media with nonlocal interaction. >>

<< Let’s describe the results obtained. First, it was shown that, depending on the number of potential wells, particles can be stationary, flying-through, or split into two subensembles of stationary and flying-through particles.  Secondly, it has been demonstrated that in the case of stationary arrangement of particles, the fully synchronous regime can become unstable due to the inhomogeneity of particle distribution between potential wells. In a partially synchronous cluster, phase incoherent elements can be located within the same potential well. Third, when stationary and flying-through elements coexist, chimera regimes are realized at each subensemble and further coexist with each other. This means that, despite the nonlocal nature of the interaction between elements of the medium, what is important for structure formation is a relatively stable mutual arrangement of particles relative to each other, which leads to a chimera state in each of the subensemble. >>️

Maxim I. Bolotov, Lev A. Smirnov, et al. Chimera states in a system of stationary and flying-through deterministic particles with an internal degree of freedom. arXiv: 2412.05044v1 [nlin.CD]. Dec 6, 2024.

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

Keywords: gst, chimera, chaos

lunedì 23 dicembre 2024

# gst: apropos of interweavings, linking dispersion and stirring in randomly braiding flows.

     Fig. 5 (a)

<< Many random flows, including 2D unsteady and stagnation-free 3D steady flows, exhibit non-trivial braiding of pathlines as they evolve in time or space. (AA) show that these random flows belong to a pathline braiding 'universality class' that quantitatively links dispersion and chaotic stirring, meaning that the Lyapunov exponent can be estimated from the purely advective transverse dispersivity. (AA) verify this quantitative link for both unsteady 2D and steady 3D random flows. This result uncovers a deep connection between transport and mixing over a broad class of random flows. >>️

Daniel R. Lester, Michael G. Trefry, Guy Metcalfe. Linking Dispersion and Stirring in Randomly Braiding Flows. arXiv: 2412.05407v1 [physics.flu-dyn]. Dec 6, 2024.

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

Keywords: gst, random, random flows, randomly braiding flows, chaos


sabato 14 dicembre 2024

# gst: self-organized chimera states in pulse-coupled oscillator systems.

<< Coupled oscillator systems can lead to states in which synchrony and chaos coexist. These states are called “chimera states.” >>
AA << study a variation of a pulse-coupled oscillator (PCO) model that has been shown to produce chimera states, demonstrate that it reproduces several of the expected chimera properties, like the formation of multiple heads and the ability to control the natural drift that Kuramoto's chimera states experience in a ring, and explain how chimera states emerge. >>️

<< Three notable aspects of chimeras in our PCO networks (with time-discrete coupling) are the absence of firing events from the tail (which still almost synchronize their phases), the reliable onset of the phenomenon from virtually any initial configuration, and the lack of a superimposed structure (e.g., artificially splitting the population into subgroups) and thus the self-organized nature of the phenomenon. >>️

Arke Vogell, Udo Schilcher, et al. Chimera states in pulse-coupled oscillator systems. Phys. Rev. E 110, 054214. Nov 26, 2024.

Also: chimera, self-assembly, chaos, network,  in https://www.inkgmr.net/kwrds.html 

Keywords: gst, chimera, self-assembly, chaos, network 


venerdì 13 dicembre 2024

# game: balance exploration and exploitation, making decisions cooperatively without sharing information.


<< Multiagent reinforcement learning (MARL) studies crucial principles that are applicable to a variety of fields, including wireless networking and autonomous driving. (AA) propose a photonic-based decision-making algorithm to address one of the most fundamental problems in MARL, called the competitive multiarmed bandit (CMAB) problem. >>

AA << demonstrate that chaotic oscillations and cluster synchronization of optically coupled lasers, along with (their) proposed decentralized coupling adjustment, efficiently balance exploration and exploitation while facilitating cooperative decision making without explicitly sharing information among agents. >>

AA << study demonstrates how decentralized reinforcement learning can be achieved by exploiting complex physical processes controlled by simple algorithms. >>

Shun Kotoku, Takatomo Mihana, et al. Decentralized multiagent reinforcement learning algorithm using a cluster-synchronized laser network. Phys. Rev. E 110, 064212. Dec 11, 2024.


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

Keywords: game, cooperation, chaos, exploration, exploitation, ai, artificial intelligence, MARL, CMAB.


venerdì 22 novembre 2024

# gst: protected chaos in a topological lattice.

<< The erratic nature of chaotic behavior is thought to erode the stability of periodic behavior, including topological oscillations. However, (AA) discover that in the presence of chaos, non-trivial topology not only endures but also provides robust protection to chaotic dynamics within a topological lattice hosting non-linear oscillators. >>

<< Despite the difficulty in defining topological invariants in non-linear settings, non-trivial topological robustness still persists in the parametric state of chaotic boundary oscillations. (AA) demonstrate this interplay between chaos and topology by incorporating chaotic Chua's circuits into a topological Su-Schrieffer-Heeger (SSH) circuit. >>

<< By extrapolating from the linear limit to deep into the non-linear regime, (AA) find that distinctive correlations in the bulk and edge scroll dynamics effectively capture the topological origin of the protected chaos. (Their)  findings suggest that topologically protected chaos can be robustly achieved across a broad spectrum of periodically-driven systems, thereby offering new avenues for the design of resilient and adaptable non-linear networks. >>️

Haydar Sahin, Hakan Akgün, et al. Protected chaos in a topological lattice. arXiv: 2411.07522v1 [cond-mat.mes-hall]. Nov 12, 2024.

Also: chaos, random, instability, transition, network, ai (artificial intell), in https://www.inkgmr.net/kwrds.html 

Keywords: gst, chaos, random,  instability, transition, network, AI, Artificial Intelligence