# brain: fast neural noise stabilizes associative memory against slow synaptic noise.

<< ️Neural systems operate under multi-timescale stochastic dynamics, yet reliably maintain stable functions. (AA) investigate how fast neural fluctuations and slow synaptic variability asymmetrically influence the structural robustness of associative memories. >>

<< While synaptic noise degrades memory formation, neural noise stabilizes the network against structural perturbations. For sequential learning of multiple memories, the average recall performance is maximized at an intermediate neural-noise amplitude, whereas increasing synaptic noise rapidly degrades memory performance. >>

<< Using an adiabatic mean-field framework, (AA) derive an analytical stationary distribution of stability factors. (Their) theory reveals that fast neural fluctuations push the system away from marginal stability, serving as an indispensable prerequisite for systemic stability. >>

Tomoki Kurikawa, Kunihiko Kaneko. Fast Neural Noise Stabilizes Associative Memory against Slow Synaptic Noise. arXiv: 2611.00516v1 [cond-mat.dis-nn]. Oct 31, 2026.

https://arxiv.org/abs/2611.00516

Also: brain, neuro, fluctuations, randomness, instability, noise, network, in https://www.inkgmr.net/kwrds.html 

Keywords: brain, neuro, synapse, fluctuations, randomness, instability, network, stochasticity, multi-timescale stochastic dynamics, neural fluctuations, fast neural fluctuations, slow synaptic variability, asymmetrical influence, associative memory, synaptic noise, structural perturbations, sequential learning, memory performance, marginal stability, systemic stability.

# gst: experimental constraints for population balance modeling in the bubbly-nonbubbly transition region of cavitating flows.

<< ️The bubbly-nonbubbly transition region characterizes the edge of cavitation and involves active dynamics of dispersed vapor bubbles. Experimental data in this region are essential for developing numerical models that bridge dispersed bubbles and macroscopic vapor cavities, with the population balance model being a representative example. >>

<< In this study (AA) perform point-by-point measurements of cavitating flow around a twisted hydrofoil using an optical probe system, obtaining local void fraction, bubble size, and velocity. The void-fraction and streamwise bubble-velocity profiles both exhibit self-similar behavior. The void-fraction profile is well fitted by a Gaussian function, which closely resembles the Gaussian form of the vertical gradient of the streamwise bubble velocity. This gradient arises from the error-function distribution of the bubble-velocity profile. The similarity between these two Gaussian profiles suggests a connection between high vapor concentration and strong shear in the bubble-velocity field. >>

<< ️Nevertheless, their characteristic widths reveal distinct spreading scales. This scale separation gives an effective bubble-momentum-based Schmidt number of Sceff≈1.63, indicating that bubble-velocity recovery extends over a broader region than vapor-concentration spreading. The bubble size distributions exhibit distinct characteristics depending on the local flow conditions: the inner region features high void fraction and strong shear, and the outer region shows low void fraction and weak shear. The typical −4/3 scaling for small bubbles is observed in both regions, whereas the −10/3 power law scaling is observed only in the outer region, where the flow approaches isotropic turbulence. Within the strong shear region, large bubbles are abundant and thus the size distribution exhibits a flatter slope. This finding suggests that the choice of a presumed distribution function in population-balance modeling should be region-dependent within the cavitation zone. >>

<< ️The experimental data further demonstrate that bubble velocities are strongly size-dependent and vary across different flow regions, offering a potential basis for modeling the slip velocity of bubbles that do not strictly follow the liquid phase. Overall, this (AA) study provides experimental constraints for closing the population balance model, which governs the transport and diffusion of dispersed vapor bubbles in cavitating flows. >>

Hao Zhang, Mingjin Wen, Yunqiao Liu, et al. Experimental constraints for population balance modeling in the bubbly-nonbubbly transition region of cavitating flows. Phys. Rev. Fluids 11, 114301. Nov 3, 2026.

https://journals.aps.org/prfluids/abstract/10.1103/fkwm-d8t3

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

Keywords: gst, bubbles, transitions, turbulence, dispersed vapor bubbles, bubbly-nonbubbly transition, cavitation, vapor cavities, void-fraction profile, strong shear in the bubble-velocity field, isotropic turbulence.

# gst: direct numerical simulation of coherent structures in narrow buoyant plumes in the presence of rotation.

<< ️Most existing studies of the effects of rotation on the Rayleigh–Taylor instability consider stratified layers. However, in nature and in the laboratory, localized sources of unstable buoyancy are also commonly observed. >>

<< ️(AA) report on laboratory-scale direct numerical simulations of isolated buoyancy sources interacting with a preexisting pycnocline. (They) demonstrate that for a readily accessible parameter range, long-lived, coherent structures that share characteristics of plumes and eddies spontaneously develop. These plumes interact with the pycnocline, but never fully penetrate it. In contrast, strong rotation leads to a surface-trapped response appearing as sheets in laboratory experiments. >>

<< ️Finally, (AA) demonstrate that temperature-induced changes in buoyancy behave differently than salt-induced changes, due to the lower diffusivity in the latter that reduces plume dilution and increases penetration into and through the stratified layer. This distinction is important because the majority of experimental literature involves salt-induced stratification. >>

Zarin Tasneem, Alain Gervais, Marek Stastna. Direct numerical simulation of coherent structures in narrow buoyant plumes in the presence of rotation. Phys. Rev. Fluids 11, 114802. Nov 3, 2026.

https://journals.aps.org/prfluids/abstract/10.1103/dfpc-hn3d

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

Keywords: gst, instability, vortex, transition, plumes & thermals, Rayleigh-Taylor instability, localized sources of unstable buoyancy, pycnocline, surface-trapped response.

# gst: valleys within valleys, a chaos picture of spin glasses.

<< ️(AA) presented the chaos picture, a novel, coherent, and intuitive theoretical framework for spin glasses that reconciles the forty-year-old debate between the droplet model and RSB (replica symmetry breaking). (AA) argue how a “valleys within valleys” hierarchical energy landscape is sculpted via the pinning and dynamic filtering of random droplets. As the temperature decreases, the chaos picture describes a progressive freezing of scale-dependent droplets in real space, and a corresponding hierarchical fracturing of the free-energy landscape in phase space, and temperature chaos, which leads to dynamic pure state coexistence. The chaos picture explains that many pure states and costly droplet excitations can coexist at the disorder-averaged level. >>

<< ️Crucially, the core mechanisms are independent of interface geometry, naturally accommodating an interface crossover from planar to fractal, and ultimately to space-filling surfaces as the dimensionality increases. >>

<< ️Finally, the chaos picture provides unified, profound insights into nonequilibrium spin-glass dynamics, while offering a streamlined reinterpretation of the complex metastate framework. >>

Wenlong Wang. Chaos picture of spin glasses. arXiv: 2610.37426v1 [cond-mat.dis-nn]. Oct 27, 2026.

https://arxiv.org/abs/2610.37426

Also: drop, droplet, droploid, chaos, disorder, random, fracture, crack, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drops, droplets, droploids, chaos, disorder, randomness, fracture, crack, spin-glass dynamics, chaos picture, replica symmetry breaking, aging, rejuvenation, memory effects. 

# gst: multiplicity of elastic wave propagation in random polycrystals.

<< ️The coherent elastic wave in untextured polycrystals, central to ultrasonic and seismic characterization, was recently observed to have two modes per polarization at short wavelengths. However, their physical origin and amplitude partition have remained open. >>

<< ️(AA) address both by theory, grain-scale numerical simulations and a grain velocity estimate. The first-order smoothing approximation, simplified by the far-field approximation, predicts three waves, which are the classical effective wave and one for each type of scattered wave (longitudinal and transverse). >>

<< ️At long wavelengths, only the effective wave is weakly attenuated. At short wavelengths, one of the other two waves joins it with comparable attenuation, whereas the third stays far more attenuated. A new residue method, which needs no fitting, gives the same pattern for the amplitude partition, with the two waves sharing the coherent field and the third carrying little. The simulations reveal exactly these two modes, for transverse waves in iron and longitudinal waves in strongly anisotropic SrMgSn, and never the third. >>

<< ️The wavefields reveal the mechanism, in which the incident wave is extinguished within one grain correlation length and the coherent field is rebuilt by forward multiple scattering. Strikingly, a grain velocity estimate from single-crystal constants provides independent evidence, tracing the two modes to plane waves of the individual grains and closely reproducing their velocities. Observability of multiple waves is thus set by attenuation and amplitude partition together, and short-wavelength measurements in random media must allow for more than one coherent mode. >>

Ming Huang, Stanislav I. Rokhlin, Michael J. S. Lowe. Multiplicity of elastic wave propagation in random polycrystals.  arXiv: 2611.04058v1 [cond-mat.mtrl-sci]. Nov 2, 2026.

https://arxiv.org/abs/2611.04058

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

Keywords: gst, waves, elastic waves, scattered waves, longitudinal waves, transverse waves, randomness, random polycrystals.

# life: learning by confusion locates a parametrization-dependent Fisher information maximum.

<< ️Learning by confusion (LBC) is a machine-learning method for locating phase transitions without assuming a known order parameter. Its characteristic accuracy curve contains a central maximum that is interpreted as the transition point, but what determines the location and finite-size scaling of this maximum has remained unclear. >>

<< ️(AA) derive an exact balance condition for the Bayes-optimal confusion peak and show that, for equilibrium systems with a single swept parameter, the peak closely follows the maximum of the corresponding Fisher information. This immediately gives its finite-size scaling and reveals an unexpected dependence on how the data are sampled: the same configurations arranged on grids uniform in T, lnT, or β=1/T can yield different finite-size pseudocritical trajectories. >>

<< Tests on the Ising, Blume-Capel, Potts, and Baxter-Wu models confirm the prediction across continuous, tricritical, and first-order transitions. (AA) results identify the statistical quantity measured by LBC and show that finite-size machine-learning estimates can depend on the parametrization of the training data as well as on the underlying physics. >>

George Issa, Richard Scalettar. Learning by Confusion Locates a Parametrization-Dependent Fisher Information Maximum. arXiv: 2610.34769v2 [cond-mat.stat-mech]. Nov 2, 2026.

https://arxiv.org/abs/2610.34769

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

Keywords: ai, artificial intelligence, machine-learning, learning by confusion, Bayes-optimal confusion peak, finite-size pseudocritical trajectories, transitions.

# gst: apropos of dispersed flowing droploids, microfluidic oscillatory rheology of transported soft entities.

<< ️Microfluidic channels have emerged as useful tools to control dynamic forcing on transported microscale objects, as encountered in emulsions, biological flows, and other soft-matter systems. Tailored channel designs enable precise interfacial and bulk rheological measurements of complex materials over a wide range of forcing timescales. >>

<< ️(AA) discuss perspectives for future research in this direction, including the study of lubrication films in highly confined droplets, the measurement of fast relaxation dynamics of complex interfaces, and the high-throughput rheological characterization of microscopic soft-matter systems ranging from single macromolecules to cells. >>

Matteo Milani, Joshua D. McGraw, Anke Lindner, et al. Microfluidic oscillatory rheology of transported soft particles. Phys. Rev. E 114, 041005. Oct 22, 2026.

https://journals.aps.org/pre/abstract/10.1103/sn3p-jrq5

arXiv: 2605.29842v2 [cond-mat.soft]. May 28, 2026.

https://arxiv.org/abs/2605.29842

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

Keywords: gst, particles, drops, droplets, droploids, microfluidics, rheology.