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lunedì 23 febbraio 2026

# gst: steady states in a model of opposing local and nonlocal hops.

<< ️(AA) study a one-dimensional lattice model of particles following hard-core exclusion and performing opposing local and nonlocal moves with probability 𝑝 and 1−𝑝, respectively. (Their) model shows the interesting feature that the direction of the particle current can be switched by simply changing the density 𝜌 of particles on the lattice. (They) study the dependence of current on 𝑝 as well as 𝜌 and present the separation of positive and negative current regions on a 𝑝−𝜌 plane. >>

<< ️Further, (They) study the effect of disorder on this model by introducing a single site with valvelike dynamics. The site allows only unidirectional, local outward motion with rate 𝑟. The interplay of the disorder strength 𝑟, particle density 𝜌, and probability 𝑝 leads to a rich possibility with four different kinds of shock phases in the steady state. >>

<< ️(They) study the shock densities using Monte Carlo simulations and mean field calculations. While (Their) mean field treatment describes the numerical results quite well qualitatively, (AA) see certain quantitative deviations. (They) try to understand these deviations using measures of correlation in the system and provide heuristic arguments for the mismatch. >>

Ankur Mishra, Apoorva Nagar. Steady states in a model of opposing local and nonlocal hops. Phys. Rev. E 113, 024113. Feb 10, 2026.

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

Keywords: gst, particles, disorder, phase transitions, shock phases, valvelike dynamics.

sabato 21 febbraio 2026

# gst: phase-controlled elastic, inelastic, and coalescent collisions of two-dimensional flat-top solitons.

<< ️(AA) investigate elastic, inelastic, and coalescent collisions between two-dimensional flat-top solitons supported by the cubic-quintic nonlinear Schrödinger equation. Numerical simulations reveal distinct collision regimes ranging from nearly elastic scattering to strongly inelastic interactions leading to long-lived merged states. >>

<< ️(They) demonstrate that the transition between these regimes is primarily controlled by the relative phase of the solitons at the collision point, with out-of-phase collisions suppressing overlap and in-phase collisions promoting strong interaction. >>

<< ️Kinetic-energy diagnostics are introduced to quantitatively characterize collision outcomes and to identify phase- and separation-dependent windows of elasticity. To interpret the observed dynamics, (They) extract effective phase-dependent interaction potentials from collision trajectories, providing a mechanical picture of attraction and repulsion between flat-top solitons. The stability of merged states formed after strongly inelastic collisions is explained by their lower energetic cost, arising from interfacial energetics, where a balance between internal pressure and edge tension plays a central role. A variational analysis based on direct energy minimization supports this picture by revealing robust energetic minima associated with stationary two-dimensional flat-top solitons. >>

M. O. D. Alotaibi, Y. O. A. Abughnheim, L. Al Sakkaf, et al. Phase-controlled elastic, inelastic, and coalescent collisions of two-dimensional flat-top solitons. arXiv: 2602.07762v1 [nlin.PS]. Feb 8, 2026.

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

Keywords: gst, soliton, transitions, elastic, inelastic, and coalescent collisions, elastic scattering interactions, strongly inelastic interactions, long-lived merged states, attraction, repulsion, internal pressure, edge tension.

venerdì 20 febbraio 2026

# gst: defect states as a precursor of the chimera states in a ring of non-locally coupled oscillators.


<< ️(AA) investigate the transition from synchronized to chimera states in a ring of non-locally coupled phase oscillators. (Their) focus is on the intermediate defect states, where solitary waves in the phase gradient profile travel at a constant speed. These traveling defects serve as a dynamical precursor for the nucleation of chimera clusters. The fraction of samples exhibiting defect states increases with the phase delay α and peaks at α_c, where the system crosses over to asynchronous states filled with chimera clusters. While the traveling speed, number, and width of these defects increase with α, the total spatial extent of the defects remains robust against the system size N. >> 

Tianjing Zhou, Nariya Uchida. Defect states as a precursor of the chimera states in a ring of non-locally coupled oscillators. arXiv: 2602.10533v1 [nlin.AO]. Feb 11, 2026.

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

Keywords: gst, transitions, chimera, chimera clusters, coupled phase oscillators, intermediate defect states, solitary waves, asynchronous states. 

giovedì 19 febbraio 2026

# gst: elastoplastic modelling of cyclic shear deformation of amorphous solids.

IMG - Per site elastic energy evolution for poorly vs well annealed samples.

<< ️(AA) develop an energy-landscape based elasto-plastic model to understand the behaviour of amorphous solids under uniform and cyclic shear. Amorphous solids are modeled as being composed of mesoscopic sub-volumes, each of which may occupy states - termed mesostates -- drawn from a specified distribution. The energies of the mesostates under stress free conditions determine their stability range with respect to applied strain, and their plastic strain, at which they are stress free, forms an important additional property. Under applied global strain, mesostates that reach their stability limits transition to other permissible mesostates. Barring such transitions, which encompass plastic deformations that the solid may undergo, mesostates are treated as exhibiting linear elastic behavior, and the interactions between mesoscopic blocks are treated using the finite element method.  >>

<< ️The (AA) model reproduces known phenomena under uniform and cyclic shear, such as the brittle-to-ductile crossover with annealing and the Bauschinger effect for uniform shear, qualitative features of the yielding diagram under cyclic shear including the change in yielding behaviour with the degree of annealing, across a `threshold level', and dynamic phenomena such as the divergence of failure times on approach to the yield point and the non-monotonic evolution of the local yield rate.  >>

<< ️In addition to these results, (They) discuss the dependence of the observed behaviour on model choices, and open questions highlighted by (Their) work. >>

Pushkar Khandare, Srikanth Sastry. Elastoplastic Modelling of Cyclic Shear Deformation of Amorphous Solids. arXiv: 2602.06174v2 [cond-mat.soft]. Feb 5,  2026.

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

Keywords: gst, transitions, amorphous solids, cyclic shear, mesostates, mesoscopic sub-volumes, plastic strain, plastic deformation, linear elastic behavior, stability limits transition, brittle-to-ductile crossover, divergence of failure times.

mercoledì 18 febbraio 2026

# gst: dynamics of small bubbles in turbulence in non-dilute conditions.


<< Turbulent flows laden with small bubbles are ubiquitous in many natural and industrial environments. From the point of view of numerical modeling, to be able to handle a very large number of small bubbles in direct numerical simulations, one traditionally relies on the one-way coupling paradigm. There, bubbles are passively advected and are noninteracting, implicitly assuming dilute conditions. >>

<< Here, (AA) study bubbles that are four-way coupled, where both the feedback on the fluid and excluded-volume interactions between bubbles are taken into account. (They) find that, while the back reaction from the bubble phase onto the fluid phase remains energetically small under most circumstances, the excluded-volume interactions between bubbles can have a significant influence on the Lagrangian statistics of the bubble dynamics. (They) show that as the volume fraction of bubbles increases, the preferential concentration of bubbles in filamentary high-vorticity regions decreases as these strong vortical structures get filled up; this happens at a volume fraction of around one percent for Re𝜆=𝒪⁡(10^2). >>

<< (AA) furthermore study the influence on the Lagrangian velocity-structure function as well as pair dispersion, and find that, while the mean dispersive behavior remains close to that obtained from one-way coupling simulations, some evident signatures of bubble collisions can be retrieved from the structure functions and the distribution of the dispersion, even at very small volume fractions. >>

Xander M. de Wit, Hessel J. Adelerhof, André Freitas, et al. Dynamics of small bubbles in turbulence in non-dilute conditions. Phys. Rev. Fluids 11, 024602. Feb 5, 2026.

arXiv: 2510.03968v2 [physics.flu-dyn]. Jan 29, 2026.

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

Keywords: gst, bubble, bubble dynamics, bubble collisions, turbulence, one-way coupling, four-way coupling.

lunedì 16 febbraio 2026

# life: the role played by women in shaping human evolution.

<< ️(AA) have used ancient DNA to reveal that hunter-gatherers in one part of Europe survived for thousands of years longer than anywhere else on the continent—and have uncovered the pivotal role of women in the process >>

<< ️Ancient DNA studies often bring to light unexpected pages of our past. We might anticipate finding the unexpected when analyzing samples from unexplored or peripheral regions of the globe. But here we are looking at the heartland of Europe, making these results even more striking. It's a testament to the power of ancient DNA studies that findings like these can still surprise us. This study has also brought to light the crucial role played by women in the transmission of knowledge from the incoming farming communities to the local hunter-gatherers. Thanks to ancient DNA studies, we can not only uncover the past but also give voice to the invaluable but often overlooked role played by women in shaping human evolution. >> Maria Pala. 

Gaby Clark, Robert Egan. Ancient DNA suggests hunter-gatherers in Europe's lowlands endured until 2500 BCE. University of Huddersfield. http://www.hud.ac.uk  Feb 11, 2026.

Olalde, I., Altena, E., Bourgeois, Q. et al. Lasting Lower Rhine–Meuse forager ancestry shaped Bell Beaker expansion. Nature (2026). https://doi.org/10.1038/s41586-026-10111-8

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

Keywords: Nomads, transitions, life

sabato 14 febbraio 2026

# gst: spatial self-organization driven by temporal noise.

<< ️The counterintuitive emergence of order from noise is a central phenomenon in science, ranging from pattern formation and synchronization to order-by-disorder in frustrated systems. While large-scale spatial self-organization induced by local spatial noise is well studied, whether temporal noise can also drive such organization remains an open question. >>

<< ️Here, by studying interacting particle systems, (AA) show that temporally correlated noise can lead to a self-organized state with suppressed long-range density fluctuations, or hyperuniformity. Further, (They) develop a fluctuating hydrodynamic theory that quantitatively explains the origin of this phenomenon. >>

<< ️Finally, by casting the dynamics as a stochastic optimization problem, (They) show that temporal correlations lead to better solutions, akin to perturbed gradient descent in neural networks -- where noise is injected during training to escape poor minima. This reveals a striking correspondence between perturbed gradient descent dynamics on the energy landscapes of particle systems and the loss landscapes of neural networks. >>

Satyam Anand, Guanming Zhang, Stefano Martiniani. Spatial self-organization driven by temporal noise. arXiv: 2601.23098v1 [cond-mat.soft]. Jan 30, 2026.

Also: self-assembly, noise, order, disorder, disorder & fluctuations, particle, escape, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, self-assembly, noise, order, disorder, disorder & fluctuations, particles, networks, neural networks, spatial noise, temporal noise, noise-driven self-organization.

mercoledì 11 febbraio 2026

# phys: probing quantum mechanics with nanoparticle matter-wave interferometry.

<< ️The quantum superposition principle is a fundamental concept of physics and the basis of numerous quantum technologies. Yet, it is still often regarded counterintuitive because we do not observe its key features on the macroscopic scales of our daily lives. It is, therefore, interesting to ask how quantum properties persist or change as we increase the size and complexity of objects. >>

<< ️A model test for this question can be realized by matter-wave interferometry, in which the motion of individual massive particles becomes delocalized and needs to be described by a wave function that spans regions far larger than the particle itself. Over the years, this has been explored with a series of objects of increasing mass and complexity and a growing community aims at pushing this to ever larger limits. >>

<< ️Here (AA) present an experimental platform that extends matter-wave interference to large metal clusters, a qualitatively new material class for quantum experiments. (They) specifically demonstrate quantum interference of sodium nanoparticles, which can each contain more than 7,000 atoms at masses greater than 170,000 Da. They propagate in a Schrödinger cat state with a macroscopicity of μ = 15.5, surpassing previous experiments by an order of magnitude. >>

Sebastian Pedalino, Bruno E. Ramírez-Galindo, Richard Ferstl, et al. Probing quantum mechanics with nanoparticle matter-wave interferometry. Nature 649, 866–870. Jan 21, 2026.

Also: keyword 'quantum' in FonT

Keywords: particles, quantum mechanics, quantum superposition.

martedì 10 febbraio 2026

# gst: rising bubbles draw surface patterns.


<< ️Small bubbles rising in a chain can self-organize into regular patterns upon reaching a liquid's free surface. This phenomenon is investigated (by AA) through direct numerical simulations. By varying the bubble release period, distinct branching patterns characterized by different numbers of arms are observed. These macroscopic patterns are found to stem from localized interactions between the bubbles, the free surface, and the surrounding liquid flow. >>

<< A heuristic model is proposed that quantitatively relates the number of arms to the bubble release period and predicts the probability of observing specific arm counts. This (AA) study provides insights into broader nonlinear pattern formation and self-organization phenomena. >>

Dabao Li, Lang Qin, Zhigang Zuo, et al. Rising bubbles draw surface patterns: A numerical study. Phys. Rev. Fluids 11, 023602. Feb 6, 2026.

arXiv: 2509.01315v2 [physics.flu-dyn]. Jan 27, 2026.

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

Keywords: gst, bubble, self-assembly, branching patterns.

sabato 7 febbraio 2026

# gst: fractals in rate-induced tipping.

<< ️When parameters of a dynamical system change sufficiently fast, critical transitions can take place even in the absence of bifurcations. This phenomenon is known as rate-induced tipping and has been reported in a variety of systems, from simple ordinary differential equations and maps to mathematical models in climate sciences and ecology. In most examples, the transition happens at a critical rate of parameter change, a rate-induced tipping point, and is associated with a simple unstable orbit (edge state). >>

<< ️In this work, (AA) show how this simple picture changes when non-attracting fractal sets exist in the autonomous system, a ubiquitous situation in non-linear dynamics. (They) show that these fractals in phase space induce fractals in parameter space, which control the rates and parameter changes that result in tipping. (They) explain how such rate-induced fractals appear and how the fractal dimensions of the different sets are related to each other. >>

<< ️(AA) illustrate (Their) general theory in three paradigmatic systems: a piecewise linear one-dimensional map, the two-dimensional Hénon map, and a forced pendulum. >>

Jason Qianchuan Wang, Yi Zheng, Eduardo G. Altmann. Fractals in rate-induced tipping. arXiv: 2601.16373v1 [nlin.CD]. Jan 23, 2026.

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

Keywords: gst, transitions, pendulum, forced pendulum, fractals, absence of bifurcations, rate-induced tipping, criticality.

venerdì 6 febbraio 2026

# gst: directionality and node heterogeneity reshape criticality in hypergraph percolation.


<< Directed and heterogeneous hypergraphs capture directional higher-order interactions with intrinsically asymmetric functional dependencies among nodes. As a result, damage to certain nodes can suppress entire hyperedges, whereas failure of others only weakens interactions. Metabolic reaction networks offer an intuitive example of such asymmetric dependencies. >>

<< Here (AA) develop a message-passing and statistical mechanics framework for percolation in directed hypergraphs that explicitly incorporates directionality and node heterogeneity. Remarkably, (They)  show that these hypergraph features have a fundamental effect on the critical properties of hypergraph percolation, reshaping criticality in a way that depends on network structure. >>

<< Specifically, (AA) derive anomalous critical exponents that depend on whether node or hyperedge percolation is considered in maximally correlated, heavy-tailed regimes. These theoretical predictions are validated on synthetic hypergraph models and on a real directed metabolic network, opening new perspectives for the characterization of the robustness and resilience of real-world directed, heterogeneous higher-order networks. >>

Yunxue Sun, Xueming Liu, Ginestra Bianconi. Directionality and node heterogeneity reshape criticality in hypergraph percolation. arXiv: 2601.20726v1 [cond-mat.dis-nn]. Jan 28, 2026.

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

Keywords: gst, networks, transitions, criticality, hypergraph, percolation, anchor nodes.

mercoledì 4 febbraio 2026

# gst: anisotropic active Brownian particle in two dimensions under stochastic resetting.

<< ️(AA) study the dynamical behavior of an anisotropic active Brownian particle subjected to various stochastic resetting protocols in two dimensions. The motion of shape-asymmetric active Brownian particles in two dimensions leads to anisotropic diffusion at short times, whereas rotational diffusion causes the transport to become isotropic at longer times. >>

<< ️(They) have considered three different resetting protocols: (1) complete resetting, when both position and orientation are reset to their initial states, (2) only the position is reset to its initial state, and (3) only orientation is reset to its initial state. >>

<< ️(They) reveal that orientational resetting sustains anisotropy even at late times. When both the spatial position and orientation are subject to resetting, a complex position probability distribution forms in the steady state. This distribution is shaped by factors such as the initial orientation angle, the anisotropy of the particle, and the resetting rate. >>

<< ️When only the translational degrees of freedom are reset, while the particle's orientation evolves naturally, the steady state no longer depends on particle asymmetry. In contrast, if only the orientation is reset, the long-term probability distribution becomes Gaussian, using an effective diffusion tensor—containing nondiagonal elements—defined by the resetting rate. More broadly, the interaction between translational and rotational dynamics, in combination with stochastic resetting, produces distinct behaviors at late times that are absent in symmetric particles. >>

<< ️Given recent progress in experimental resetting techniques, these (AA) results could be highly useful for controlling asymmetric active colloids, such as in self-assembly applications. >>

Anirban Ghosh, Sudipta Mandal, Subhasish Chaki. Anisotropic active Brownian particle in two dimensions under stochastic resetting. Phys. Rev. E 113, 014142. Jan 29, 2026.

arXiv: 2501.05149v2 [cond-mat.stat-mech]. Nov 25, 2025. 

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

Keywords: gst, particle, self-assembly, stochastic resetting.

martedì 3 febbraio 2026

# gst: nonlocal Kramers-Moyal formulas and data-driven discovery of stochastic dynamical systems with multiplicative Lévy noise.

<< ️Traditional data-driven methods, effective for deterministic systems or stochastic differential equations (SDEs) with Gaussian noise, fail to handle the discontinuous sample paths and heavy-tailed fluctuations characteristic of Lévy processes, particularly when the noise is state-dependent. >>

<< ️To bridge this gap, (AA) establish nonlocal Kramers-Moyal formulas, rigorously generalizing the classical Kramers-Moyal relations to SDEs with multiplicative Lévy noise. These formulas provide a direct link between short-time transition probability densities (or sample path statistics) and the underlying SDE coefficients: the drift vector, diffusion matrix, Lévy jump measure kernel, and Lévy noise intensity functions. >>

<< This (AA) work provides a principled and practical toolbox for discovering interpretable SDE models governing complex systems influenced by discontinuous, heavy-tailed, state-dependent fluctuations, with broad applicability in climate science, neuroscience, epidemiology, finance, and biological physics. >>

Yang Li, Jinqiao Duan. Nonlocal Kramers-Moyal formulas and data-driven discovery of stochastic dynamical systems with multiplicative Lévy noise. arXiv: 2601.19223v1 [math.DS]. Jan 27, 2026.

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

Keywords: gst, noise, randomness, transitions, fluctuations.