# gst: symmetry breaking in time-dependent billiards.

AA << investigate symmetry breaking in a time-dependent billiard that undergoes a continuous phase transition when dissipation is introduced. The system presents unlimited velocity, and thus energy growth for the conservative dynamics. When inelastic collisions are introduced between the particle and the boundary, the velocity reaches a plateau after the crossover iteration. The system presents the expected behavior for this type of transition, including scale invariance, critical exponents related by scaling laws, and an order parameter approaching zero in the crossover iteration. >>

AA << analyze the velocity spectrum and its averages for dissipative and conservative dynamics. The transition point in velocity behavior caused by the physical limit of the boundary velocity and by the introduced dissipation coincides with the crossover interaction obtained from the Vrms (root mean sq V) curves. Additionally, (they) examine the velocity distributions, which lose their symmetry once the particle's velocity approaches the lower limit imposed by the boundary's motion and the system's control parameters. This distribution is also characterized analytically by an expression P(V,n), which attains a stationary state, with a well-defined upper bound, only in the dissipative case. >>

Anne Kétri Pasquinelli da Fonseca, Edson Denis Leonel. Symmetry breaking in time-dependent billiards. arXiv: 2505.20488v1 [nlin.CD]. May 26, 2025.

https://arxiv.org/abs/2505.20488

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

Keywords: gst, billiard, particles, transitions, dissipation, symmetry breaking, inelastic collisions.

# gst: transition to inverse cascade in turbulent rotating convection in absence of the large-scale vortex.

<< Turbulent convection under strong rotation can develop an inverse cascade of kinetic energy from smaller to larger scales. In the absence of an effective dissipation mechanism at the large scales, this leads to the pile-up of kinetic energy at the largest available scale, yielding a system-wide large-scale vortex (LSV). Earlier works have shown that the transition into this state is abrupt and discontinuous. >>

Here, AA << study the transition to the inverse cascade in the case where the inverse energy flux is dissipated before it reaches the system scale, suppressing the LSV formation. (They) demonstrate how this can be achieved in direct numerical simulations by using an adapted form of hypoviscosity on the horizontal manifold. (They) find that in the absence of the LSV, the transition to the inverse cascade becomes continuous. This shows that it is the interaction between the LSV and the background turbulence that is responsible for the observed discontinuity. >>

AA << furthermore show that the inverse cascade in absence of the LSV has a more local signature compared to the case with LSV. >>️

Xander M. de Wit. Transition to inverse cascade in turbulent rotating convection in absence of the large-scale vortex. arXiv: 2502.16275v1 [physics.flu-dyn]. Feb 22, 2025. 

https://arxiv.org/abs/2502.16275

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

Keywords: gst, turbulence, dissipation, transitions, vortices

# gst: multiple Pareto-optimal solutions of the dissipation-adaptation trade-off

<< Adaptation refers to the ability to recover and maintain “normal” function on perturbations of internal or external conditions and is essential for sustaining life. Biological adaptation mechanisms are dissipative, i.e., they require a supply of energy such as the coupling to the hydrolysis of ATP. Via evolution the underlying biochemical machinery of living organisms evolved into highly optimized states. However, in the case of adaptation processes two quantities are optimized simultaneously, the adaptation speed or accuracy and the thermodynamic cost. In such cases one typically faces a trade-off, where improving one quantity implies worsening the other. The solution is no longer unique but rather a Pareto set—the set of all physically attainable protocols along which no quantity can be improved without worsening another. >> 

AA << investigate Pareto fronts in adaptation-dissipation trade-offs for a cellular thermostat and a minimal ATP-driven receptor-ligand reaction network. (They) find convex sections of Pareto fronts to be interrupted by concave regions, implying the coexistence of distinct optimization mechanisms. (They) discuss the implications of such “compromise-optimal” solutions and argue that they may endow biological systems with a superior flexibility to evolve, resist, and adapt to different environments. >>️

Jorge Tabanera-Bravo, Aljaz Godec. Multiple Pareto-optimal solutions of the dissipation-adaptation trade-off. 

Phys. Rev. Research 7, 013020. Jan 7, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.7.013020

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

Also: 'adaptation' in FonT  https://flashontrack.blogspot.com/search?q=adaptation   in Notes (quasi-stochastic poetry) (a) https://inkpi.blogspot.com/search?q=adaptation   

(b) https://inkpi.blogspot.com/search?q=adattamento

Keywords: gst, adaptation, dissipation

# gst: trade-off between coherence and dissipation for excitable phase oscillators.

<< Thermodynamic uncertainty relation (TUR) bounds coherence in stochastic oscillatory systems. In this paper, (AA) show that both dynamical and thermodynamic bounds play important roles for the excitable oscillators, e.g. neurons. >>

<< Excitable systems such as neurons have distinctive coherence features compared with other oscillators having no excitability. >>️

AA << combined the well-established results, i.e. the fluctuation of the ISI (inter-spike-interval) limited by 1/3 and the coherence resonance phenomenon, together with the TUR developed in recent years to investigate the coherence in the excitable phase oscillators. (AA) find quite different trade-off relation in the subthreshold (excitable) region and superthreshold (oscillatory) region, separated by the SNIC (saddle-node on an invariant circle) bound but meanwhile lower bounded by the TUR. Furthermore, (They) found that there is an optimal entropy production corresponding to the maximum coherence, which could serve as an alternative interpretation of the coherence resonance. It implies that more entropy production does not necessarily result in higher accuracy of currents. >>️

Chunming Zheng. Trade-off between coherence and dissipation for excitable phase oscillators. arXiv: 2412.16603v1 [cond-mat.stat-mech]. Dec 21, 2024.

https://arxiv.org/abs/2412.16603

Also: brain, entropy, dissipation, uncertainty, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, brain, neurons, entropy, oscillators, excitable phase oscillators, coherence, dissipation, uncertainty

# gst: transitions, how two saddles can increase the transient times.

FIG. 8. Attractor and chaotic saddles (..) amplified around three bands of the chaotic attractor.  The global chaotic saddle is colored blue, and the local chaotic saddle is colored red. The attractors are colored black. 

AA << consider a dissipative version of the standard nontwist map. Nontwist systems present a robust transport barrier, called the shearless curve, that becomes the shearless attractor when dissipation is introduced. This attractor can be regular or chaotic depending on the control parameters. Chaotic attractors can undergo sudden and qualitative changes as a parameter is varied. These changes are called crises, and at an interior crisis the attractor suddenly expands. Chaotic saddles are nonattracting chaotic sets that play a fundamental role in the dynamics of nonlinear systems, they are responsible for chaotic transients, fractal basin boundaries, chaotic scattering and they mediate interior crises. >>

<< In this work (AA) discuss the creation of chaotic saddles in a dissipative nontwist system and the interior crises they generate. (They) show how the presence of two saddles increase the transient times and analyze the phenomenon of crisis induced intermittency. >>️

Rodrigo Simile Baroni, Ricardo Egydio de Carvalho, et al. Chaotic saddles and interior crises in a dissipative nontwist system. arXiv: 2211.06921v1 [nlin.CD]. Nov 13, 2022. 

https://arxiv.org/abs/2211.06921

Also

keyword 'intermittency' in FonT

https://flashontrack.blogspot.com/search?q=intermittency

keyword 'dissipation' in FonT

https://flashontrack.blogspot.com/search?q=dissipation

keyword 'saddle' in FonT

https://flashontrack.blogspot.com/search?q=saddle

keyword 'chaos' | 'chaotic' in Font

https://flashontrack.blogspot.com/search?q=chaos

https://flashontrack.blogspot.com/search?q=chaotic

keyword 'caos' | 'caotico' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=caos

https://inkpi.blogspot.com/search?q=caotico

Keywords: gst, transitions, dissipation, 

dissipative systems, chaos, saddle, chaotic saddle, crisis, interior crisis, intermittency

# gst: a concrete image, chirality by dissipation, 'this effect actually owes its existence to dissipation'

<< Normally, dissipation alters or weakens existing quantum effects-but here we have an effect that actually owes its existence to dissipation, >>  Tilman Esslinger

<< "No scientist thinks in formulae," Albert Einstein allegedly once told his colleague Leopold Infeld. In fact, especially for physicists, who deal with such abstract things as quantum physics, it is often immensely useful to work with concrete images rather than mathematical symbols. >>

Oliver Morsch. Unexpected twist in a quantum system. ETH Zurich.  Jan 10, 2020.

https://m.phys.org/news/2020-01-unexpected-quantum.html

Nishant Dogra, Manuele Landini, et al.  Dissipation-induced structural instability and chiral dynamics in a quantum gas.  Science  20 Dec 2019:

Vol. 366, Issue 6472, pp. 1496-1499

DOI: 10.1126/science.aaw4465

https://science.sciencemag.org/content/366/6472/1496