# gst: dynamics and chaotic properties of the fully disordered Kuramoto model.

<< ️Frustrated random interactions are a key ingredient of spin glasses. From this perspective, (AA) study the dynamics of the Kuramoto model with quenched random couplings: the simplest oscillator ensemble with fully disordered interactions. (AA) answer some open questions by means of extensive numerical simulations and a perturbative calculation (the cavity method). (They) show frequency entrainment is not realized in the thermodynamic limit and that chaotic dynamics are pervasive in parameter space.  >>

<< ️In the weak coupling regime, (AA) find closed formulas for the frequency shift and the dissipativeness of the model. Interestingly, the largest Lyapunov exponent is found to exhibit the same asymptotic dependence on the coupling constant irrespective of the coupling asymmetry, within the numerical accuracy. >>

Iván León, Diego Pazó. Dynamics and chaotic properties of the fully disordered Kuramoto model. arXiv:2507.05168v1 [cond-mat.dis-nn]. Jul 7, 2025.

https://arxiv.org/abs/2507.05168

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

Keywords: gst, disorder & fluctuations, weakness, chaos, transitions, volcano transition, slow relaxation, quasientrainment, freezing, nonreciprocity.

# gst: chimera states with multiple coexisting solutions.

AA << ️report on the emergence of chimera states in extended systems characterized by the coexistence of more than two spatiotemporal solutions. Specifically, (They) show that three-domain chimeras may generically appear in reaction-diffusion systems under three conditions, with a crucial role played by the existence of a Maxwell point. >>

AA << verify the universality of (their) findings by analyzing five different models, and demonstrate that such new chimeras are independent of the boundary conditions imposed. >>

Gui-Quan Sun, Zhi-Chao Xue, et al. Chimera states with multiple coexisting solutions. Phys. Rev. Research 7, 023289. Jun 20, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/y3t8-bk24

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

Keywords: gst, chimera, chaos, transitions.

# gst: wave-kinetic dynamics of forced-dissipated turbulent internal gravity waves

<< Internal gravity waves are an essential feature of stratified media, such as oceans and atmospheres. >>

<< To investigate their dynamics, (AA) perform simulations of the forced-dissipated kinetic equation describing the evolution of the energy spectrum of weakly nonlinear internal gravity waves. >>

<< During the early evolution, three well-known nonlocal interactions, the elastic scattering, the induced diffusion, and the parametric subharmonic instability, together with a superharmonic resonance play a prominent role. >>

<< In contrast, local interactions are responsible for anisotropic energy cascade on longer timescales. >>

AA << reveal emergence of a condensate at small horizontal wave vectors that can be interpreted as a pure wave-wave interaction-mediated layering process. >>

Vincent Labarre, Giorgio Krstulovic, Sergey Nazarenko. Wave-Kinetic Dynamics of Forced-Dissipated Turbulent Internal Gravity Waves. Phys. Rev. Lett. 135, 014101. Jul 1, 2025.

https://journals.aps.org/prl/abstract/10.1103/b82h-z21n

arXiv:2407.11469v3 [physics.flu-dyn]. Mar 28, 2025.

https://arxiv.org/abs/2407.11469

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

Keywords: gst, waves, weakness, turbulence, transitions, stratified turbulence, wave-turbulence interactions, weak turbulence.

# gst: energy spectra and fluxes of 2D turbulent quantum droplets.

AA << explore the energy spectra and associated fluxes of turbulent two-dimensional quantum droplets subjected to a rotating paddling potential which is removed after a few oscillation periods. A systematic analysis on the impact of the characteristics (height and velocity) of the rotating potential and the droplet atom number reveals the emergence of different dynamical response regimes. >>

<< ️Significant distortions are observed in the droplet periphery in the presence of a harmonic trap. A direct energy cascade (from large to small length scales) is mainly identified through the flux. >>

Their << ️findings offer insights into the turbulent response of exotic phases of matter, featuring quantum fluctuations, and may inspire investigations aiming to unravel self-similar nonequilibrium dynamics. >>

Shawan Kumar Jha, Mahendra K. Verma, et al. Energy spectra and fluxes of two-dimensional turbulent quantum droplets. Phys. Rev. Fluids 10, 064618. Jun 25, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/pj6n-3w6p

arXiv:2501.01771v1 [cond-mat.quant-gas]. Jan 3, 2025.

https://arxiv.org/abs/2501.01771

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

Keywords: gst, drop, droplet, droploid, turbulence, vortex, harmonic trap, quantum fluctuations, exotic phases of matter, self-similar nonequilibrium dynamics

# gst: the evasion of tipping; pattern formation near a Turing-fold bifurcation

<< ️Model studies indicate that many climate subsystems, especially ecosystems, may be vulnerable to 'tipping': a 'catastrophic process' in which a system, driven by gradually changing external factors, abruptly transitions (or 'collapses') from a preferred state to a less desirable one. In ecosystems, the emergence of spatial patterns has traditionally been interpreted as a possible 'early warning signal' for tipping. More recently, however, pattern formation has been proposed to serve a fundamentally different role: as a mechanism through which an (eco)system may 'evade tipping' by forming stable patterns that persist beyond the tipping point. >>

<< ️Mathematically, tipping is typically associated with a saddle-node bifurcation, while pattern formation is normally driven by a Turing bifurcation. Therefore, (AA) study the co-dimension 2 Turing-fold bifurcation and investigate the question: 'When can patterns initiated by the Turing bifurcation enable a system to evade tipping?' >>

AA << develop (their) approach for a class of phase-field models and subsequently apply it to -component reaction-diffusion systems -- a class of PDEs often used in ecosystem modeling. (AA) demonstrate that a two-component system of modulation equations governs pattern formation near a Turing-fold bifurcation, and that tipping will be evaded when a critical parameter, β, is positive. (They) derive explicit expressions for β, allowing one to determine whether a given system may evade tipping. Moreover, (They) show numerically that this system exhibits rich behavior, ranging from stable, stationary, spatially quasi-periodic patterns to irregular, spatio-temporal, chaos-like dynamics. >>

Dock Staal, Arjen Doelman. The evasion of tipping: pattern formation near a Turing-fold bifurcation. arXiv: 2506.22251v1 [math.DS]. Jun 27, 2025.

https://arxiv.org/abs/2506.22251

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

Keywords: gst, disorder & fluctuations, pattern formation, Turing-fold bifurcation, transitions, tipping, collapse

# gst: allosteric lever: toward a principle of specific allosteric response.

<< ️Allostery, the phenomenon by which the perturbation of a molecule at one site alters its behavior at a remote functional site, enables control over biomolecular function. >>

<< ️However, a general principle of allostery, i.e., a set of quantitative and transferable “ground rules,” remains elusive. It is neither a set of structural motifs nor intrinsic motions. >>

<< ️Focusing on elastic network models, (AA) here show that an allosteric lever—a mode-coupling pattern induced by the perturbation—governs the directional, source-to-target, allosteric communication: A structural perturbation of an allosteric site couples the excitation of localized hard elastic modes with concerted long-range soft-mode relaxation. >>

<< ️Perturbations of nonallosteric sites instead couple hard and soft modes uniformly. The allosteric response is shown to be generally nonlinear and nonreciprocal, and allows for minimal structural distortions to be efficiently transmitted to specific changes at distant sites. Allosteric levers exist in proteins and “pseudoproteins”—networks designed to display an allosteric response. >>

<< ️Interestingly, protein sequences that constitute allosteric transmission channels are shown to be evolutionarily conserved. >>

Maximilian Vossel, Bert L. de Groot, Aljaž Godec. Allosteric Lever: Toward a Principle of Specific Allosteric Response. Phys. Rev. X 15, 021097. Jun 20, 2025

https://journals.aps.org/prx/abstract/10.1103/wv2k-676p

Also: allostery in FonT https://flashontrack.blogspot.com/search?q=allostery

Also: allosterico in Notes (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=allosterico

Keywords: gst, allostery, allosteric lever, elasticity, networks, elastic networks.

# gst: transient and steady-state chaos in dissipative quantum systems.

<< Dissipative quantum chaos plays a central role in the characterization and control of information scrambling, non-unitary evolution, and thermalization, but it still lacks a precise definition. >>

AA << properly restore the quantum-classical correspondence through a dynamical approach based on entanglement entropy and out-of-time-order correlators (OTOCs), which reveal signatures of chaos beyond spectral statistics. Focusing on the open anisotropic Dicke model, (They) identify two distinct regimes: transient chaos, marked by rapid early-time growth of entanglement and OTOCs followed by low saturation values, and steady-state chaos, characterized by high long-time values. >>

AA << introduce a random matrix toy model and show that Ginibre spectral statistics signals short-time chaos rather than steady-state chaos. (Their) results establish entanglement dynamics and OTOCs as reliable diagnostics of dissipative quantum chaos across different timescales. >>

Debabrata Mondal, Lea F. Santos, S. Sinha. Transient and steady-state chaos in dissipative quantum systems. arXiv: 2506.05475v1 [quant-ph]. Jun 5, 2025. 

https://arxiv.org/abs/2506.05475

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

Keywords: gst, information scrambling, entropy, chaos, transient chaos, steady-state chaos.