# gst: cascade tipping, cascade hopping and indirect tipping in ecological systems.

<< ️Tipping occurs when an abrupt transition is observed in a system's long-term behavior. This study demonstrates tipping in ecological systems using a unidirectional, three-species coupled system, where only the first subsystem experiences a ramp-like parameter drift. Using a model of bacteria, phytoplankton, and fish populations, (AA) explore how environmental changes, coupling strength, and nonlinearity drive sudden transitions.  >>

<< ️This (AA) study identifies three crucial tipping phenomena based on the coupling strength: tipping cascade, cascade hopping, and indirect tipping. While prior research has focused on tipping cascade and cascade hopping, this work introduces indirect tipping as a critical phenomenon, where the tertiary subsystem tips even when both the primary and secondary subsystems do not tip. The results emphasize the vulnerability of coupled systems to minor changes and highlight the necessity of closely observing systems that appear untipped in coupled systems. >>

Ayanava Basak, Syamal Kumar Dana, Nandadulal Bairagi. Cascade tipping, cascade hopping and indirect tipping in ecological systems. Phys. Rev. E 112, 044225. Oct 24, 2025.

https://journals.aps.org/pre/abstract/10.1103/sn5v-xyb5

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

Keywords: gst, transitions, cascade tipping, cascade hopping, indirect tipping.

# gst: coupling an elastic string to an active bath: the emergence of inverse damping.

<< ️The interaction between continuous media and particles is a central topic in much of modern physics, and this (AA) paper specifically addresses the transfer of persistence and activity between particles and waves. Indeed, setting up a nonequilibrium dynamics of continuous (field) degrees of freedom requires understanding how that arises from coupling with active matter degrees of freedom. >>

<< ️Within that program, (AA) have studied a system of fast-moving, overdamped, run-and-tumble particles moving on and interacting with a slower string modeled as a scalar Klein-Gordon field. Using time scale separation and weak coupling, (They) have derived an effective fluctuation dynamics for the field after integrating out the active bath. Akin to Landau (inverse) damping, the particles induce friction on the scalar field given by an explicit time correlation for bath observables. >>

<< ️Depending on the level of activity and persistence of the active particles (and their velocity distribution), this friction can be negative, leading to instability. This emergence of negative (linear) friction for an elastic string extends previous results where the probe is a slow inertial particle in an active medium, (..), except that the acceleration (creating transverse waves) is orthogonal to the active motion. >>

Aaron Beyen, Christian Maes, Ji-Hui Pei. Coupling an elastic string to an active bath: The emergence of inverse damping. arXiv: 2505.18665v2 [cond-mat.stat-mech]. Sep 1, 2025.

https://arxiv.org/abs/2505.18665

Phys. Rev. E 112, L042103. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/g1zm-23sq

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

Keywords: gst, particles, run-and-tumble particles, waves, elasticity, elastic strings, wave-particle interactions.

# gst: cascade crack in chain of beads.

<< ️(AA) consider a homogeneous chain of spheres linked by liquid bridges under tension. The rupture of a single liquid bridge leads to a fragmentation cascade driven by the inverse relation between the capillary force and the sphere distances. The initial length of the liquid bridges determines the number and size of the fragments and the velocity of the fragmentation front. >>

Meysam Bagheri, Thorsten Pöschel. Cascade Crack in Chain of Beads. arXiv: 2508.01288v1 [cond-mat.soft]. Aug 2, 2025.

https://arxiv.org/abs/2508.01288

Phys. Rev. E 112, 045414. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/hzs3-8ffk

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

Keywords: gst, crack, fracture, fragmentation cascade.

# gst: transition to chaos with conical billiards.

<< ️In this paper, (AA) introduced and extensively investigated dynamical billiards on the surface of a cone with a tilted base. Upon varying the cone angle β, corresponding to a deficit angle 

2πχ = 2π(1 − sin(β)), and tilt angle γ, (They) identified three distinct types of trajectories with associated Poincaré map for conical billiards: rim, hourglass, and mixed. >>

<< ️Region I, where Poincaré space consists of rim, hourglass, and mixed trajectories; Region IIB, where Poincaré space consists of only hourglass and mixed trajectories; and Region IIA, in which (They) find choices of γ and χ for which almost all trajectories are strongly mixing. (..) (AA) also developed a scheme for identifying strongly mixing trajectories. >>

<< ️Furthermore, (They) were able to show that a dynamical billiard on a surface with exclusively convex and positive Gaussian curvature in three dimensions can still exhibit ergodic behavior in certain parameter regimes. >>

<< ️A particularly intriguing feature of this system is that by tuning χ and γ, nearly all points in (θ,ϕ) Poincaré space describing conical line segments in between bounces can be placed at the edge between chaotic and integrable dynamics. Thus this work highlights the potential of conical billiards as a model system for exploring intriguing problems inspired by neural networks at the “edge of chaos”. >>

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

Phys. Rev. E 112, 044221. Oct 21, 2025.

https://journals.aps.org/pre/abstract/10.1103/18f7-sqhz

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

Keywords: gst, billiards, conical billiard, chaos, transitions, neural networks

# aibot: Tensor Logic, a hypothesis for the next step in artificial intelligence.

<< ️Progress in AI is hindered by the lack of a programming language with all the requisite features. Libraries like PyTorch and TensorFlow provide automatic differentiation and efficient GPU implementation, but are additions to Python, which was never intended for AI. Their lack of support for automated reasoning and knowledge acquisition has led to a long and costly series of hacky attempts to tack them on. >>

<< ️On the other hand, AI languages like LISP and Prolog lack scalability and support for learning. This (AA) paper proposes tensor logic, a language that solves these problems by unifying neural and symbolic AI at a fundamental level. The sole construct in tensor logic is the tensor equation, based on the observation that logical rules and Einstein summation are essentially the same operation, and all else can be reduced to them. (AA) show how to elegantly implement key forms of neural, symbolic and statistical AI in tensor logic, including transformers, formal reasoning, kernel machines and graphical models. >>

<< ️Most importantly, tensor logic makes new directions possible, such as sound reasoning in embedding space. This combines the scalability and learnability of neural networks with the reliability and transparency of symbolic reasoning, and is potentially a basis for the wider adoption of AI. >>

Pedro Domingos. Tensor Logic: The Language of AI. arXiv: 2510.12269v3 [cs.AI]. Oct 16, 2025.

https://arxiv.org/abs/2510.12269

Also: Millie Marconi. 20ott25 https://x.com/Yesterday_work_/status/1980265546068402492 repost tgn0s937k https://x.com/tgn0s937k30472

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

Keywords: ai, aibot, artificial intelligence, tensor logic, unifying neural- symbolic- statistical- AI.

# gst: gigantic dynamical spreading and anomalous diffusion of jerky active particles.

<< ️Jerky active particles are Brownian self-propelled particles which are dominated by “jerk,” the change in acceleration. They represent a generalization of inertial active particles. In order to describe jerky active particles, a linear jerk equation of motion which involves a third-order derivative in time, Stokes friction, and a spring force (AA) combined with activity modeled by an active Ornstein-Uhlenbeck process. This equation of motion (They) solved analytically and the associated mean-square displacement (MSD) is extracted as a function of time. >>

<< ️For small damping and small spring constants, the MSD shows an enormous superballistic spreading with different scaling regimes characterized by anomalous high dynamical exponents 6, 5, 4, or 3 arising from a competition among jerk, inertia, and activity. When exposed to a harmonic potential, the gigantic spreading tendency induced by jerk gives rise to an enormous increase of the kinetic temperature and even to a sharp localization-delocalization transition, i.e., a jerky particle can escape from harmonic confinement. >>

<< ️The transition can be either first or second order as a function of jerkiness. Finally (AA)  shown that self-propelled jerky particles governed by the basic equation of motion can be realized experimentally both in feedback-controlled macroscopic particles and in active colloids governed by friction with memory. >>

Hartmut Löwen. Gigantic dynamical spreading and anomalous diffusion of jerky active particles. Phys. Rev. E 112, 045412. Oct 17, 2025.

https://journals.aps.org/pre/abstract/10.1103/976t-qry7

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

Keywords: gst, particles, colloids, self-propelled particles, active Brownian particles, Jerky active particles, jerkiness, transitions, superballistic spreading, escape.

# gst: triadic percolation on multilayer networks.

<< ️Triadic interactions are special types of higher-order interactions that occur when regulator nodes modulate the interactions between other two or more nodes. In presence of triadic interactions, a percolation process occurring on a single-layer network becomes a fully-fledged dynamical system, characterized by period-doubling and a route to chaos. >>

<< ️Here, (AA) generalize the model to multilayer networks and name it as the multilayer triadic percolation (MTP) model. (They) find a much richer dynamical behavior of the MTP model than its single-layer counterpart. MTP displays a Neimark-Sacker bifurcation, leading to oscillations of arbitrarily large period or pseudo-periodic oscillations. >>

<< Moreover, MTP admits period-two oscillations without negative regulatory interactions, whereas single-layer systems only display discontinuous hybrid transitions.  >> 

Hanlin Sun, Filippo Radicchi, Ginestra Bianconi. Triadic percolation on multilayer networks. arXiv: 2510.09341v1 [nlin.AO]. Oct 10, 2025.

https://arxiv.org/abs/2510.09341

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

Keywords: gst, network, chaos, 

percolation, multilayer triadic 

percolation, higher-order 

interactions, triadic interactions.

# gst: apropos of waves that escape trapping; on internal wave whispering gallery modes in channels and critical-slope wave attractors.

<< ️Internal waves are an important feature of stratified fluids, both in oceanic and lake basins and in other settings. Many works have been published on the generic feature of internal wave trapping onto planar wave attractors and super-attractors in 2D & 3D and the exceptional class of standing global internal wave modes. >>

<< ️However, most of these works did not deal with waves that escape trapping. By using continuous symmetries (AA) analytically prove the existence of internal wave Whispering Gallery Modes (WGMs), internal waves that propagate continuously without getting trapped by attractors. WGMs neutral stability with respect to different perturbations enable whispering gallery beams, a continuum of rays propagating together coherently. The systems' continuous symmetries also enable projection onto 2D planes that yield effective 2D billiards preserving the original dynamics. >>

<< ️By examining rays deviating from these WGMs in parabolic channels (They) discover a new type of wave attractor which is located along the channel instead of across it as in previous works. This new wave attractor leads to a re-understanding of WGMs as sitting at the border between the two basins of attraction. >>

<< ️Finally, both critical-slope wave attractors and whispering gallery beams are used to propose explanations for along-channel energy fluxes in submarine canyons and tidal energy intensification near critical slopes. >>

Nimrod Bratspiess, Eyal Heifetz, Leo R. M. Maas. On internal wave whispering gallery modes in channels and critical-slope wave attractors. arXiv: 2510.07218v1 [physics.flu-dyn]. Oct 8, 2025.

https://arxiv.org/abs/2510.07218

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

Keywords: gst, waves, internal waves, internal wave whispering gallery modes (WGMs), wave attractors, basins of attraction, billiards.

# gst: apropos of stochastic resetting, abrupt transitions in the optimization of diffusion with distributed resetting.

<< ️Brownian diffusion subject to stochastic resetting to a fixed position has been widely studied for applications to random search processes. In an unbounded domain, the mean first-passage time at a target site can be minimized for a convenient choice of the resetting rate. >>

<< ️Here (AA) study this optimization problem in one dimension when resetting occurs to random positions, chosen from a probability density function with compact support that does not include the target. Depending on the shape of this distribution, the optimal resetting rate either varies smoothly with the mean distance to the target, as in single-site resetting, or exhibits a discontinuity caused by the presence of a second local minimum in the mean first-passage time. These two regimes are separated by a critical line containing a singular point that (They) characterize through a Ginzburg-Landau theory. >>

<< ️To quantify how useful is a given resetting point for the search, (AA) calculate the probability density function of the last resetting position before absorption. The discontinuous transition separates two markedly different optimal strategies: one with a small resetting rate where the last path before absorption starts from a rather distant but likely position, while the other strategy has a large resetting rate, favoring last paths starting from not-so-likely points but which are closer to the target. >>

Pedro Julián-Salgado, Leonardo Dagdug, Denis Boyer. Abrupt transitions in the optimization of diffusion with distributed resetting. Phys. Rev. E 112, 044110. Oct 6, 2025.

https://journals.aps.org/pre/abstract/10.1103/b15f-47qw

arXiv: 2507.14483v2 [cond-mat.stat-mech]. Oct 7, 2025.

https://arxiv.org/abs/2507.14483

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

Keywords: gst, randomness, transitions, stochastic resetting, small-- large resetting rate.

# gst: effects of inertia on the asynchronous state of a disordered Kuramoto model.

<< ️(AA) investigate the role of inertia in the asynchronous state of a disordered Kuramoto model. (They) extend an iterative simulation scheme to the case of the Kuramoto model with inertia in order to determine the self-consistent fluctuation statistics, specifically, the power spectra of network noise and single oscillators. >>

<< ️Comparison with network simulations demonstrates that this works well whenever the system is in an asynchronous state. >>

 

 << ️(AA) also find an unexpected effect when varying the degree of inertia: the correlation time of the oscillators becomes minimal at an intermediate mass of the oscillators; correspondingly, the power spectra appear flatter and thus more similar to white noise around the same value of mass. (They) also find a similar effect for the Lyapunov spectra of the oscillators when the mass is varied. >>

Yagmur Kati, Ralf Toenjes, Benjamin Lindner. Effects of inertia on the asynchronous state of a disordered Kuramoto model. Phys. Rev. E 112, 044301. Oct 6, 2025.

https://journals.aps.org/pre/abstract/10.1103/xt4m-bkp8

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

Keywords: gst, networks, noise, order, disorder, fluctuations, inertia, asynchronous states, transitions, Kuramoto model.

# gst: predicting the response of structurally altered and asymmetrical networks.

<< ️(AA) investigate how the response of coupled dynamical systems is modified due to a structural alteration of the interaction. >>

<< ️The majority of the literature focuses on additive perturbations and symmetrical interaction networks. Here, (They) consider the challenging problem of multiplicative structural alterations and asymmetrical interaction coupling. >>

<< ️(AA) introduce a framework to approximate the averaged response at each network node for general structural alterations, including non-normal and asymmetrical ones. (Their) findings indicate that both the asymmetry and non-normality of the structural alterations impact the global and local responses at different orders in time. (They) propose a set of matrices to identify the nodes whose response is affected the most by the structural alteration. >>

Melvyn Tyloo. Predicting the response of structurally altered and asymmetrical networks. Phys. Rev. E 112, L042301. Oct 10, 2025. 

https://journals.aps.org/pre/abstract/10.1103/3s3d-qr4l

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

Keywords: gst, networks, disorder & fluctuations, transitions.

# gst: why and when merging surface nanobubbles jump.

<< Gas bubble accumulation on substrates reduces the efficiency of many physicochemical processes, such as water electrolysis. For microbubbles, where buoyancy is negligible, coalescence-induced jumping driven by the release of surface energy provides an efficient pathway for their early detachment. >>

<< At the nanoscale, however, gas compressibility breaks volume conservation during coalescence, suppressing surface energy release and seemingly disabling this detachment route. >>

<< Using molecular dynamics simulations, continuum numerical simulations, and theoretical analysis, (AA) show that surface nanobubbles with sufficiently large contact angles can nevertheless detach after coalescence. In this regime, detachment is powered by the release of pressure energy associated with nanobubble volume expansion. This (AA) finding thus establishes a unified driving mechanism for coalescence-induced bubble detachment across all length scales. >>

Yixin Zhang, Xiangyu Zhang, Detlef Lohse. Why and when merging surface nanobubbles jump. arXiv: 2509.22934v1 [cond-mat.soft]. Sep 26, 2025.

https://arxiv.org/abs/2509.22934

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

Keywords: gst, bubbles, surface nanobubbles, surface energy release, coalescence, coalescence-induced jumping, coalescence-induced bubble detachment.

# gst: random trajectories in bounded domains

<< ️Can we deduce the total length of a random trajectory by observing only its local path segments within a confined domain? Surprisingly, the answer is yes—for curves randomly placed and oriented in space, whether stochastic or deterministic; generated by ballistic or diffusive dynamics; possibly interrupted by stopping or branching; and in two or more dimensions. More precisely, the mean total length ⟨𝐿⟩ relates to the mean in-domain path length ⟨ℓ⟩ and the mean chord length of the domain ⟨𝜎⟩ via the following simple and universal relation:

              1/⟨ℓ⟩ = 1/⟨𝐿⟩ + 1/⟨𝜎⟩

Here, ⟨𝜎⟩ is a purely geometric quantity, dependent only on the volume-to-surface ratio of the domain. Derived solely from the kinematic formula of integral geometry, the result is independent of step-length statistics, memory, absorption, and branching, making it equally relevant to photons in turbid tissue, active bacteria in microchannels, cosmic rays in molecular clouds, or neutron chains in nuclear reactors. Monte Carlo simulations spanning straight needles, Y shapes, and isotropic random walks in two and and three dimensions confirm the universality and demonstrate how a local measurement of ⟨ℓ⟩ yields ⟨𝐿⟩ without ever tracking the full trajectory. >>

T. Binzoni, E. Dumonteil, A. Mazzolo. Universal property of random trajectories in bounded domains. Phys. Rev. E 112, 044105. Oct 3, 2025.

https://journals.aps.org/pre/abstract/10.1103/dng6-9519

arXiv: 2011.06343v3 [math-ph]. May 16, 2025. 

https://arxiv.org/abs/2011.06343

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

Also: voli a casaccio (quasi-stochastic poetry). Oct 01, 2006.

https://inkpi.blogspot.com/2006/10/2066-voli-casaccio.html

Keywords: gst, randomness, random trajectories,  walk, random walk, bounded domains.

# gst: self-organized adaptive branching in frangible matter.

<< ️Soft and frangible materials that remodel under flow can give rise to branched patterns shaped by material properties, boundary conditions, and the time scales of forcing. (AA) present a general theoretical framework for emergent branching in these frangible (or threshold) materials that switch abruptly from resisting flow to permitting flow once local stresses exceed a threshold, relevant for examples as varied as dielectric breakdown of insulators and the erosion of soft materials. >>

<< ️Simulations in 2D and 3D show that branching is adaptive and tunable via boundary conditions and domain geometry, offering a foundation for self-organized engineering of functional transport architectures. >>

P.L.B. Fischer, J. Tauber, L. Mahadevan. Self-organized adaptive branching in frangible matter. arXiv: 2509.26101v1 [cond-mat.soft]. Sep 30, 2025.

https://arxiv.org/abs/2509.26101

Also: fracture, crack, self-assembly, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, fracture, crack, self-assembly, transitions, self-organized adaptive branching, soft-- frangible materials, emergent branching, branched patterns, resisting-- permitting flow, erosions.

# brain: exploring aperiodic, complexity and entropic brain changes during non-ordinary states of consciousness.

<< ️Non-ordinary states of consciousness (NOC) provide an opportunity to experience highly intense, unique, and perceptually rich subjective states. The neural mechanisms supporting these experiences remain poorly understood. >>

<< ️This (AA) study examined brain activity associated with a self-induced, substance-free NOC known as Auto-Induced Cognitive Trance (AICT). Twenty-seven trained participants underwent high-density electroencephalography (EEG) recordings during rest and AICT. (They) analyzed the aperiodic component of the power spectrum (1/f), Lempel-Ziv complexity, and sample entropy from five-minute signal segments. A machine learning approach was used to classify rest and AICT, identify discriminative features, and localize their sources. >>

<< ️(AA) also compared EEG metrics across conditions and assessed whether baseline activity predicted the magnitude of change during AICT. Classification analyses revealed condition-specific differences in spectral exponents, complexity, and entropy. The aperiodic component showed the strongest discriminative power, followed by entropy and complexity. Source localization highlighted frontal regions, the posterior cingulate cortex, and the left parietal cortex as key contributors to the AICT state. Baseline neural activity in frontal and parietal regions predicted individual variability in the transition from rest to AICT. >>

<< ️These findings indicate that AICT engages brain regions implicated in rich subjective experiences and provide mechanistic insights into how self-induced trance states influence neural functioning. >>

Victor Oswald, Karim Jerbi, et al. Exploring aperiodic, complexity and entropic brain changes during non-ordinary states of consciousness. arXiv: 2509.19254v1 [q-bio.NC]. Sep 23, 2025.

https://arxiv.org/abs/2509.19254 

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

Keywords: brain, consciousness, auto-Induced cognitive trance (AICT), Zen.

# gst: effective-medium theory for elastic systems with correlated disorder.

<< ️Correlated structures are intimately connected to intriguing phenomena exhibited by a variety of disordered systems such as soft colloidal gels, bio-polymer networks and colloidal suspensions near a shear jamming transition. The universal critical behavior of these systems near the onset of rigidity is often described by traditional approaches as the coherent potential approximation - a versatile version of effective-medium theory that nevertheless have hitherto lacked key ingredients to describe disorder spatial correlations. >>

<< ️Here (AA) propose a multi-purpose generalization of the coherent potential approximation to describe the mechanical behavior of elastic networks with spatially-correlated disorder. (They) apply (their) theory to a simple rigidity-percolation model for colloidal gels and study the effects of correlations in both the critical point and the overall scaling behavior. (AA) find that although the presence of spatial correlations (mimicking attractive interactions of gels) shifts the critical packing fraction to lower values, suggesting sub-isostatic behavior, the critical coordination number of the associated network remains isostatic. More importantly, (AA) discuss how their theory can be employed to describe a large variety of systems with spatially-correlated disorder. >>

Jorge M. Escobar-Agudelo, Rui Aquino, Danilo B. Liarte. Effective-medium theory for elastic systems with correlated disorder. arXiv: 2510.02090v1 [cond-mat.stat-mech]. Oct 2, 2025.

https://arxiv.org/abs/2510.02090

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

Keywords: gst, elasticity, networks, elastic networks, disorder, disorder & fluctuations.

# gst: nonreciprocity induced spatiotemporal chaos: reactive vs dissipative routes.

<< ️Nonreciprocal interactions fundamentally alter the collective dynamics of nonlinear oscillator networks. Here (AA) investigate Stuart-Landau oscillators on a ring with nonreciprocal reactive or dissipative couplings combined with Kerr-type or dissipative nonlinearities. >>

<< ️Through numerical simulations and linear analysis, (They) uncover two distinct and universal pathways by which enhanced nonreciprocity drives spatiotemporal chaos. Nonreciprocal reactive coupling with Kerr-type nonlinearity amplifies instabilities through growth-rate variations, while nonreciprocal dissipative coupling with Kerr-type nonlinearity broadens eigenfrequency distributions and destroys coherence, which, upon nonlinear saturation, evolve into fully developed chaos. In contrast, dissipative nonlinearities universally suppress chaos, enforcing bounded periodic states. >>

<< ️(AA) findings establish a minimal yet general framework that goes beyond case-specific models and demonstrate that nonreciprocity provides a universal organizing principle for the onset and control of spatiotemporal chaos in oscillator networks and related complex systems. >>

Jung-Wan Ryu. Nonreciprocity induced spatiotemporal chaos: Reactive vs dissipative routes. arXiv: 2509.20992v1 [nlin.CD]. Sep 25, 2025

https://arxiv.org/abs/2509.20992

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

Keywords: gst, networks, instability, chaos, nonreciprocity, nonreciprocal interactions, nonreciprocal reactive-- dissipative couplings.

# gst: influence of boundary conditions and interfacial slip to achieve a nonequilibrium steady-state for highly confined flows

<< ️(AA) investigate the equilibration time to attain steady-state for a system of liquid molecules under boundary-driven planar Couette flow via nonequilibrium molecular dynamics (NEMD) simulation. >>

<< ️In particular, (They) examine the equilibration time for the two common types of boundary driven flow: one in which both walls slide with equal and opposite velocity, and the other in which one wall is fixed and the other moves with twice the velocity. Both flows give identical steady-state strain rates, and hence flow properties, but the transient behaviour is completely different. >>

<< ️(They) find that in the case of no-slip boundary conditions, the equilibration times for the counter-sliding walls flow are exactly 4 times faster than those of the single sliding wall system, and this is independent of the atomistic nature of the fluid, i.e., it is an entirely hydrodynamic feature. (They) also find that systems that exhibit slip have longer equilibration times in general and the ratio of equilibration times for the two types of boundary-driven flow is even more pronounced. >>

<< ️(AA) analyse the problem by decomposing a generic planar Couette flow into a linear sum of purely symmetric and antisymmetric flows. (They) find that the no-slip equilibration time is dominated by the slowest decaying eigenvalue of the solution to the Navier-Stokes equation. In the case of slip, the longest relaxation time is now dominated by the transient slip velocity response, which is longer than the no-slip response time. In the case of a high-slip system of water confined to graphene channels, the enhancement is over two orders of magnitude. >>

Carmelo Riccardo Civello, Luca Maffioli, et al. The influence of boundary conditions and interfacial slip on the time taken to achieve a nonequilibrium steady-state for highly confined flows. arXiv: 2509.20944v1 [physics.flu-dyn]. Sep 25, 2025.

https://arxiv.org/abs/2509.20944

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

Keywords: gst, transitions, transient behaviours,  fluctuations, thermal fluctuations, slipping, uncertainty, counter-sliding walls.