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martedì 11 novembre 2025

# 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.

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

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

lunedì 10 novembre 2025

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

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

sabato 8 novembre 2025

# 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.

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.

venerdì 7 novembre 2025

# 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.

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

Keywords: life, aibot, artificial intelligence.

giovedì 6 novembre 2025

# 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.

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

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

mercoledì 5 novembre 2025

# 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.

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.

lunedì 3 novembre 2025

# 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. 

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

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