# gst: avalanche assemblies in arbitrary connection topologies.

<< ️Complex systems are commonly modeled as networks of units that integrate external input and emit brief pulses of activity upon reaching a threshold. Such pulse-coupled interactions can give rise to cascades of activity propagating through the network in the form of avalanches. >>

<< While the statistics of these collective events are known to depend sensitively on network topology, rigorous analytical descriptions are usually restricted to homogeneous networks or mean-field approximations which are limited to particular aspects of generated avalanches like size and duration. >>

<< ️Here (AA) develop a mathematically rigorous theory of avalanche formation in recurrent networks of pulse-coupled units without assuming homogeneity. For arbitrary nonnegative coupling matrices, the framework provides a closed form for the avalanche assembly distribution, which quantifies the probability that a given subset of units is activated during an avalanche. >>

<< This (AA) approach represents a substantial conceptual advance over existing theories allowing analysis of the structure-function relation between network topology and detailed statistics of generated avalanches. This is particularly relevant for the irregular, highly structured, and asymmetric coupling topologies ubiquitous in natural systems, such as brain networks with pronounced columnar, modular, and hierarchical organization. >>

Maik Schünemann, Marc Kesseböhmer, Udo Ernst. Avalanche assemblies in arbitrary connection topologies. Phys. Rev. E 114, 034414. Sep 29, 2026.

https://journals.aps.org/pre/abstract/10.1103/nl7d-16n8

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

Keywords: gst, network, brain, complex systems, collective dynamics, pulse-coupled interactions, threshold cascades of activity, avalanches, avalanche assembly distribution, network topology, columnar- modular- hierarchical organization.

# life: emotions as intrinsic colored noise in biological systems.

<< ️The idea that emotions in biological systems are analogous to intrinsic colored noise (by AA) is advanced and justified. A model describing the dynamics of operation of biological networks under the influence of colored noise is suggested. >>

<< ️The agents of a biological network can be represented either by biological species, such as humans and animals, or by neurons of the brain, or by the nodes of a neural network. Operational actions, or decisions, in a biological noisy network are based not only on the evaluation of utility of alternatives, but also on the agents emotions. The model is probabilistic, with the choice of alternatives characterized by the related probabilities. >>

<< ️At the initial step, the agents make decisions individually and then start exchanging information with each other and imitating the actions of other agents, thus forming a biological network of interacting agents. Numerical simulations are accomplished for a heterogeneous society consisting of three groups of agents, one group possessing long-range memory, the other group, short-range memory, and the third group of super-rational agents acting strictly on the basis of utility, being deprived of emotions. >>

<< ️Dynamics of opinions in different groups can be smooth, oscillatory, or chaotic. Altogether, eight types of operation are found, depending on the dynamics of group decisions. Under strong imitation effect, there appears chaotic motion in the evolution of decision choice. (by AA) it is shown  how the Ellsberg paradox can be resolved and how the exchange of information influences the dynamics of this paradox. >>

V.I.Yukalov, E.P.Yukalova. Emotions as intrinsic colored noise in biological systems. arXiv: 2609.25970v1 [physics.soc-ph]. Sep 22, 2026.

https://arxiv.org/abs/2609.25970

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

Keywords: life, noise, brain, networks, biological noisy network, agents emotions, colored noise, affective operation, long-range memory, short-range memory, games.

# gst: topological phase transition driven by structural defects.

<< ️Structural defects, such as disclinations and dislocations, destroy the long-range crystalline order as they proliferate. In this work, (AA) continuously drive a system from a crystalline state on a decorated honeycomb lattice to a hyperuniform amorphous state, by consecutively introducing Stone-Wales (SW) defects, which can be viewed as dipoles of dislocations. >>

<< ️Using a topological Weaire-Thorpe Hamiltonian model to describe electrons in this system, (AA) demonstrate that SW defects can cause pseudo-band inversions and, correspondingly, a reversal of the Chern number. Using adiabatic arguments and a computationally efficient spillage indicator, (They) predict the topological phase diagram of the amorphous state from the crystalline one. (They) explain the nature of the pseudo-band inversion through the renormalization of the hopping in an effective Hamiltonian based on a single SW defect. >>

Andrii Syrota, Andrej Mesaros, Pascal Simon. Topological phase transition driven by structural defects. arXiv: 2609.26586v1 [cond-mat.dis-nn]. Sep 22, 2026. 

https://arxiv.org/abs/2609.26586

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

Keywords: gst, defect, order, disorder, transitions, structural defects, 

disclinations, dislocations, dipoles of dislocations, amorphous states, pseudo-band inversions.

# gst: disorder-promoted stability.

<< Previous studies of network dynamics have suggested that heterogeneity among nodes inhibits stability, at odds with the ubiquity of inherently heterogeneous natural and engineered systems. >>

<< ️Here, (AA) show that this conclusion arises from model reductions introduced for mathematical tractability and breaks down when nodal dynamics are higher-dimensional, yielding non-Hermitian Jacobians. In such systems, including neural, power-grid, and material networks, nodal heterogeneity can instead enhance stability, even when parameters are randomly disordered. >>

<< ️Non-Hermiticity also underlies the stabilizing effects of network heterogeneity, which can arise even in one-dimensional nodal dynamics through nonreciprocal interactions, as shown for ecological networks. >>

<< ️(AA) framework reveals disorder not as a liability but as a general resource for stabilizing complex systems. >>

Arthur N.Montanari, Pietro Zanin, Adilson E.Motter. Disorder-promoted stability. arXiv: 2609.25226v1 [cond-mat.dis-nn]. Sep 21, 2026.

https://arxiv.org/abs/2609.25226

Science. 393: 6817, 1241-1249. Sep 17, 2026. DOI: 10.1126/science.aeg3946.

https://www.science.org/doi/10.1126/science.aeg3946

Also: noise, disorder, network, game, poetry, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, noise, disorder, networks.

# gst: mixing, anisotropy, and Lagrangian dispersion in Rayleigh-Taylor turbulence under variable acceleration.

<< ️This (AA) study investigates miscible Rayleigh-Taylor (RT) turbulence subjected to gravity removal or reversal at different stages of its development, using high-resolution numerical simulations and Lagrangian passive-particle tracking. The state of the mixing layer at the switching time, particularly its thickness and turbulent intensity, is shown to control the subsequent evolution. >>

<< ️Gravity reversal transforms the unstable RT layer into a weakly turbulent, stably stratified flow with a thick mixed region. The vertical mass flux and kinetic-energy anisotropy exhibit decaying oscillations whose characteristic period increases with the mixing-layer thickness at reversal and is described by the Brunt-Väisälä frequency. >>

<< ️In contrast, gravity removal eliminates further buoyancy production without imposing a restoring force, allowing the mixing layer to continue broadening through inertial coasting while retaining the large-scale structure inherited from the preceding RT stage. The Lagrangian analysis distinguishes absolute material transport from relative turbulent stirring. >>

<< ️After gravity removal, the vertical velocity correlation remains positive over a comparatively long interval, sustaining both single-particle displacement and particle-pair separation. Gravity reversal instead drives the correlation through zero and induces particle oscillations consistent with the Brunt-Väisälä timescale, thereby suppressing both absolute transport and the relative stretching of initially neighboring particles. >>

<< ️These (AA) results show that the postswitch dynamics are governed jointly by the flow state at the switching time and by whether the modified forcing preserves or actively destroys vertical velocity memory. >>

Dongxiao Zhao, Gaojin Li. Mixing, anisotropy, and Lagrangian dispersion in Rayleigh-Taylor turbulence under variable acceleration. Phys. Rev. Fluids 11, 093903. Sep 18, 2026.

https://journals.aps.org/prfluids/abstract/10.1103/r4vw-jkyc

Also: Dongxiao Zhao, Gaojin Li. Evolution of Rayleigh-Taylor turbulence under vorticity and strain-rate control. arXiv: 2506.07012v1 [physics.flu-dyn]. Jun 8, 2025.

https://arxiv.org/abs/2506.07012

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

Keywords: gst, particles, turbulence, Lagrangian dispersion, Rayleigh-Taylor turbulence, anisotropy, reversal, buoyancy, inertial coasting, particle-pair separation, particle oscillations, vertical velocity memory, Rayleigh-Taylor instability, turbulent mixing.

# gst: rupture dynamics of dense granular films; from liquidlike bursting to solidlike fracturing.

<< ️(AA) investigate the bursting dynamics of dense granular films punctured at imposed controlled liquid pressure. Using high-speed imaging, (They) reveal a two-stage opening process.️ At early times, the hole expands in a liquidlike manner with a nearly circular shape and a constant velocity, though significantly lower than the Taylor-Culick speed. This velocity is modeled by a balance between surface tension and effective surface viscosity, which depends on particle size and liquid depression. >>

<< ️(AA) show that as liquid pressure decreases, the initial opening slows down progressively until it ultimately reaches a jamming state. As the opening progresses, the film undergoes a transition to a solidlike regime, where faceting occurs due to fracture propagation within the granular skeleton. >>

<< ️(AA) show that the characteristic fracture size follows a 𝑡3/4 scaling, consistent with a balance between surface energy release and viscous dissipation induced by liquid redistribution within the 2D granular network. ️These findings advance (Their) understanding of the mechanics of granular films and their transition between fluidlike and solidlike behaviors. >>

Paul Gauthier, Nabil Retailleau, Yacine Khidas, et al. Rupture dynamics of dense granular films: From liquidlike bursting to solidlike fracturing. Phys. Rev. Fluids 11, 094301. Sep 8, 2026.

https://journals.aps.org/prfluids/abstract/10.1103/c9bz-d2yg

Also: particle, fracture, crack, drop, droplet, droploid, bubble, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, particles, fracture, crack, drops, droplets, droploids, bubbles, transitions, fluid-particle interactions, granular fluids, granular films, granular network, bursting dynamics, surface tension, surface viscosity, viscous dissipations, jamming states, surface energy.

# gst: odd slip at chiral active surfaces.

<< ️Odd slip at solid-liquid interfaces, characterized by a velocity component perpendicular to the applied shear stress, introduces a novel class of odd transport phenomena with transverse momentum transfer at boundaries, distinct from odd viscosity, odd elasticity, or odd diffusivity. This effect arises on chiral active surfaces with persistent energy input and defined handedness, such as carpets of rotating biological or synthetic cilia with flexible anchoring. Although odd slip itself is dissipationless, its maintenance comes at an energetic cost, which we estimate from the microscopic model. With respect to its orientation dependence, odd slip can be classified as pseudo-scalar or pseudo-vectorial. >>

<< ️(AA) use a perturbative expansion to determine the resistance tensors of problems with different levels of broken symmetries. They reveal how the surface chirality and body asymmetry together violate the Onsager symmetry, but uphold the Onsager-Casimir reciprocity. Strikingly, suspensions of particles with odd slip embedded in a conventional Newtonian bulk fluid exhibit odd viscosity, providing a new minimal mechanism for its emergence beyond current microscopic models. >>

Yuto Hosaka, Andrej Vilfan. Odd slip at chiral active surfaces. arXiv: 2609.17005v2 [cond-mat.soft]. Sep 16, 2026. 

https://arxiv.org/abs/2609.17005

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

Keywords: gst, particles, solid-liquid interfaces, chiral active surfaces, surface chirality, parity-violating phenomena, shear stress, odd viscosity, odd diffusivity, odd elasticity, odd slip, broken symmetries.