# life: self-reinforcing cascades: a spreading model for beliefs or products of varying intensity or quality

<< ️Models of how things spread often assume that transmission mechanisms are fixed over time. However, social contagions—the spread of ideas, beliefs, innovations—can lose or gain in momentum as they spread: ideas can get reinforced, beliefs strengthened, products refined. >>

<< ️(AA) study the impacts of such self-reinforcement mechanisms in cascade dynamics. (They) use different mathematical modeling techniques to capture the recursive, yet changing nature of the process. >>

<< ️(AA) find a critical regime with a range of power-law cascade size distributions with nonuniversal scaling exponents. This regime clashes with classic models, where criticality requires fine-tuning at a precise critical point. Self-reinforced cascades produce critical-like behavior over a wide range of parameters, which may help explain the ubiquity of power-law distributions in empirical social data. >>

Laurent Hébert-Dufresne, Juniper Lovato, et al. Self-Reinforcing Cascades: A Spreading Model for Beliefs or Products of Varying Intensity or Quality. Phys. Rev. Lett. 135, 087401. Aug 21, 2025.

https://journals.aps.org/prl/abstract/10.1103/5mph-sws5

Also: behav, random, noise, walk, self-assembly, in https://www.inkgmr.net/kwrds.html 

Keywords: life, behavior, walk, random, random walks, noise, criticality, self-assembly, social contagions, self-reinforced cascades.

# gst: apropos of instabilities, stability of co-annular active and passive confined fluids.

<< ️The translation and shape deformations of a passive viscous Newtonian droplet immersed in an active nematic liquid crystal under circular confinement are analyzed using a linear stability analysis. (AA) focus on the case of a sharply aligned active nematic in the limit of strong elastic relaxation in two dimensions. >>

<< ️Using an active liquid crystal model, (They) employ the Lorentz reciprocal theorem for Stokes flow to study the growth of interfacial perturbations as a result of both active and elastic stresses. >>

<< ️Instabilities are uncovered in both extensile and contractile systems, for which growth rates are calculated and presented in terms of the dimensionless ratios of active, elastic, and capillary stresses, as well as the viscosity ratio between the two fluids. >>

<< ️(AA) also extend (Their) theory to analyze the inverse scenario, namely, the stability of an active nematic droplet surrounded by a passive viscous layer. (Their) results highlight the subtle interplay of capillary, active, elastic, and viscous stresses in governing droplet stability. >>

<< ️The instabilities uncovered here may be relevant to a plethora of biological active systems, from the dynamics of passive droplets in bacterial suspensions to the organization of subcellular compartments inside the cell and the cell nucleus. >>

Tanumoy Dhar, Michael J. Shelley, David Saintillan. Stability of co-annular active and passive confined fluids. Phys. Rev. Fluids 10, 083103. Aug 21, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/m5ck-v2q3

arXiv: 2501.04918v2 [cond-mat.soft]. Jul 25, 2025. 

https://arxiv.org/abs/2501.04918

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

Keywords: gst, drop, droplet, droploid, elasticity, instability, elastic relaxation, interfacial perturbations, capillary, active, elastic, and viscous stresses.

# gst: stationary-state dynamics of interacting phase oscillators in presence of noise and stochastic resetting

<< ️(AA) explore the impact of global resetting on Kuramoto-type models of coupled limit-cycle oscillators with distributed frequencies both in absence and presence of noise. The dynamics comprises repeated interruption of the bare dynamics at random times with simultaneous resetting of phases of all the oscillators to a predefined state. >>

<< ️A key finding is the pivotal role of correlations in shaping the ordering dynamics under resettling. >>

<< ️It would be interesting to consider suitable refinement to the mean-field approximation  invoked in this work in order to have a better match of analytical with simulation results. An immediate extension is to consider resetting only a subset of the degrees of freedom at random times. >>

Anish Acharya, Mrinal Sarkar, Shamik Gupta. Stationary-state dynamics of interacting phase oscillators in presence of noise and stochastic resetting. arXiv: 2504.08510v2 [cond-mat.stat-mech].  https://arxiv.org/abs/2504.08510v2

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

Keywords: gst, coupled limit-cycle oscillators, stationary-state behavior, global resetting, quenched disorder, annealed disorder, random times, noise.

# gst: hidden qu-classical correspondence in chaotic billiards revealed by mutual information.

<< ️Avoided level crossings, commonly associated with quantum chaos, are typically interpreted as signatures of eigenstate hybridization and spatial delocalization, often viewed as ergodic spreading. >>

<< ️(AA) show that, contrary to this expectation, increasing chaos in quantum billiards enhances mutual information between conjugate phase space variables, revealing nontrivial correlations. Using an information-theoretic decomposition of eigenstate entropy, (They) demonstrate that spatial delocalization may coincide with increased mutual information between position and momentum. >>

<< These correlations track classical invariant structures in phase space and persist beyond the semiclassical regime, suggesting a robust information-theoretic manifestation of quantum-classical correspondence. >>

Kyu-Won Park, Soojoon Lee, Kabgyun Jeong. Hidden quantum-classical correspondence in chaotic billiards revealed by mutual information. Phys. Rev. E 112, 024209. Aug 13, 2025.

https://journals.aps.org/pre/abstract/10.1103/qpxx-csdj

arXiv:2505.08205v1 [nlin.CD]. May 13, 2025.

https://arxiv.org/abs/2505.08205

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

Keywords: gst, billiard, chaos, qu-chaos, waves, quantum-to-classical transition

# gst: extreme event precursor prediction in turbulence.

<< ️(AA) present a general framework to predict precursors to extreme events in turbulent dynamical systems. The approach combines phase-space reconstruction techniques with recurrence matrices and convolutional neural networks (CNN) to identify precursors to extreme events. >>

<< ️(They) evaluate the framework across three distinct testbed systems: a triad turbulent interaction model, a prototype stochastic anisotropic turbulent flow, and the Kolmogorov flow. This method offers three key advantages: (1) a threshold-free classification strategy that eliminates subjective parameter tuning, (2) efficient training using only O (100) recurrence matrices, and (3) ability to generalize to unseen systems. >>

<< ️The results demonstrate robust predictive performance across all test systems: 96% detection rate for the triad model with a mean lead time of 1.8 time units, 96% for the anisotropic turbulent flow with a mean lead time of 6.1 time units, and 93% for the Kolmogorov flow with a mean lead time of 22.7 units. >> 

Rahul Agarwal, Mustafa A. Mohamad. Extreme Event Precursor Prediction in Turbulent Dynamical Systems via CNN-Augmented Recurrence Analysis. arXiv: 2508.04301v1 [cs.CE]. Aug 6, 2025.

https://arxiv.org/abs/2508.04301

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

Keywords: gst, turbulence, chaos, extreme events, convolutional neural networks (CNN).

# gst: transition to chaos with conical billiards.

<< ️(AA) adapt ideas from geometrical optics and classical billiard dynamics to consider particle trajectories with constant velocity on a cone with specular reflections off an elliptical boundary formed by the intersection with a tilted plane, with tilt angle γ. >>

<< ️(They) explore the dynamics as a function of γ and the cone deficit angle χ that controls the sharpness of the apex, where a point source of positive Gaussian curvature is concentrated. >>

<< ️(AA) find regions of the (γ,χ) plane where, depending on the initial conditions, either (A) the trajectories sample the entire cone base and avoid the apex region; (B) sample only a portion of the base region while again avoiding the apex; or (C) sample the entire cone surface much more uniformly, suggestive of ergodicity. >>

<< ️The special case of an untilted cone displays only type A trajectories which form a ring caustic at the distance of closest approach to the apex. However, (They) observe an intricate transition to chaotic dynamics dominated by Type (C) trajectories for sufficiently large χ and γ. A Poincaré map that summarizes trajectories decomposed into the geodesic segments interrupted by specular reflections provides a powerful method for visualizing the transition to chaos. (AA) then analyze the similarities and differences of the path to chaos for conical billiards with other area-preserving conservative maps. >>

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

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

Keywords: gst, billiard, particles, transitions, chaos. 

# drugs: Parrondo's paradox in tumor ecosystems; adaptive therapy strategies to delay the development of drug resistance.

<< ️Maximum tolerated dose (MTD) and low-dose metronomic (LDM) schedules are widely used clinical strategies in cancer chemotherapy despite the fact that both approaches have inherent limitations. MTD often leads to drug resistance in tumors, whereas LDM usually results in the predominance of drug-sensitive or drug-resistant cancer cells, depending on the specific dose applied. >>

<< ️To circumvent these unfavorable outcomes, (AA) propose in (Their) work a promising adaptive therapy strategy that alternates MTD and LDM schemes across the treatment cycles. By studying a three-component tumor system with replicator equations, (They) find that alternate administration of MTD and LDM at different lengths of the treatment cycle can significantly delay the development of drug-resistant phenotypes compared to when the two schemes are operated separately. >>

<< ️This outcome recapitulates the weak form of the Parrondo's paradox, where appropriate combinations of two individually suboptimal strategies can produce an even more superior outcome (a more favorable therapeutic effect in (this) case). (AA) also validate the feasibility of the proposed adaptive therapy strategy in spatially distributed tumor ecosystems by implementing agent-based simulations. (Their) findings offer potential clues to the challenges in state-of-the-art adaptive therapy methods, which often require precise regulation of drug dose and timing based on the proportions of drug-sensitive and drug-resistant cancer cells within a tumor. >>

De-Ming Liu, Yi-Yang Liu, et al. Parrondo's paradox in tumor ecosystems: Adaptive therapy strategies to delay the development of drug resistance. Phys. Rev. E 112, 024404. Aug 6, 2025.

https://journals.aps.org/pre/abstract/10.1103/xjh4-mfvx

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

Keywords: drugs, pharma, Parrondo's paradox, game, cancer, tumors, cancer chemotherapy, maximum tolerated dose (MTD), low-dose metronomic (LDM), drug resistance, drug sensitivity, adaptive therapy strategy.