# gst: apropos of fluctuations, an unconventional approach to (fuzzy) morphogenesis

AA << propose an unconventional mechanism where stochastic fluctuations drive the emergence of morphological patterns. >>️

In this approach << the inherent fluctuations determine the nature of the dynamics and are not incidental noise in the background of the otherwise deterministic dynamics. Instead, they play an important role as a driving force that defines the attributes of the pattern formation dynamics and the nature of the transition itself.  >>️

Oded Agam and Erez Braun. Fluctuation-driven morphological patterning: An unconventional approach to morphogenesis. Phys. Rev. Research 6, 043027. Oct 10, 2024.

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.6.043027

Also: disorder & fluctuations, self-assembly, metamorphosis, transition, noise, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, fluctuations,  self-assembly, metamorphosis, transition, noise

# gst: apropos of 'filamentous' and 'fibrous' scenarios, criticality enhances the reinforcement of disordered networks by rigid inclusions.

<< The mechanical properties of biological materials are spatially heterogeneous. Typical tissues are made up of a spanning fibrous extracellular matrix in which various inclusions, such as living cells, are embedded. >>️

<< Recent work has shown that, in isolation, such networks exhibit unusual viscoelastic behavior indicative of an underlying mechanical phase transition controlled by network connectivity and strain. How this behavior is modified when inclusions are present is unclear. >>

AA << present a theoretical and computational study of the influence of rigid inclusions on the mechanics of disordered elastic networks near the connectivity-controlled central force rigidity transition. >>️

<< Combining scaling theory and coarse-grained simulations, (AA) predict and confirm an anomalously strong dependence of the composite stiffness on inclusion volume fraction, beyond that seen in ordinary composites. (..) this enhancement is a consequence of the interplay between inter-particle spacing and an emergent correlation length, leading to an effective finite-size scaling imposed by the presence of inclusions. >>

AA << show that this enhancement is a consequence of the interplay between inter-particle spacing and an emergent correlation length, leading to an effective finite-size scaling imposed by the presence of inclusions. >>️

AA << discuss potential experimental tests and implications for (their)  predictions in real systems. >>

️

Jordan L. Shivers, Jingchen Feng, Fred C. MacKintosh. Criticality enhances the reinforcement of disordered networks by rigid inclusions. arXiv:  2407.19563v1 [cond-mat.soft]. Jul 28, 2024. 

https://arxiv.org/abs/2407.19563

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

Keywords: gst, network, transition, disorder, elasticity, rigidity, criticality, bifurcations

# gst: when generalized diffusion could result from stochastic processes.

<< Despite the success of fractional Brownian motion (fBm) in modeling systems that exhibit anomalous diffusion due to temporal correlations, recent experimental and theoretical studies highlight the necessity for a more comprehensive approach of a generalization that incorporates heterogeneities in either the tracers or the environment. >>

AA present << a modification of Lévy's representation of fBm for the case in which the generalized diffusion coefficient is a stochastic process. (They) derive analytical expressions for the autocovariance function and both ensemble- and time-averaged mean squared displacements. Further, (AA)  validate the efficacy of the developed framework in two-state systems, comparing analytical asymptotic expressions with numerical simulations. >>️

Adrian Pacheco-Pozo, Diego Krapf. Fractional Brownian motion with fluctuating diffusivities. Phys. Rev. E 110, 014105. Jul 1, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.110.014105

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

Keywords: gst, fractional Brownian motion, fBm, Lévy, disorder, fluctuations, anomalous, network, transition

# gst: chaos controlled and disorder driven phase transitions by breaking permutation symmetry

<< Introducing disorder in a system typically breaks symmetries and can introduce dramatic changes in its properties such as localization. At the same time, the clean system can have distinct many-body features depending on how chaotic it is. >>

<< In this work the effect of permutation symmetry breaking by disorder is studied in a system which has a controllable and deterministic regular to chaotic transition. >>

<< Results indicate a continuous phase transition from an area-law to a volume-law entangled phase irrespective of whether there is chaos or not, as the strength of the disorder is increased. The critical disorder strength obtained by finite size scaling, indicate a strong dependence on whether the clean system is regular or chaotic to begin with. >>

<< Additionally, (AA) find that a relatively small disorder is seen to be sufficient to delocalize a chaotic system. >>

Manju C, Arul Lakshminarayan, Uma Divakaran. Chaos controlled and disorder driven phase transitions by breaking permutation symmetry. arXiv: 2406.00521v1 [quant-ph]. Jun 1, 2024. 

https://arxiv.org/abs/2406.00521

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

Keywords: gst, transition, chaos, disorder 

FonT: who is Manju C?

# gst: inertia onset in disordered porous media flow.

AA << investigate the very onset of the inertial regime in pore-scale fluid flow in a three-dimensional, disordered porous media. >>️

Their << analysis shows that the onset of inertia observed in a standard way by computing the friction factor appears at a Reynolds number two orders of magnitude higher than indicated by analyzing tortuosity and spatial distribution of kinetic energy. >>️

Damian Sniezek, Sahrish B. Naqvi, Maciej Matyka. Inertia onset in disordered porous media flow. arXiv: 2403.00456v2 [physics.flu-dyn]. Mar 26, 2024. 

https://arxiv.org/abs/2403.00456

Also: inertia, disorder, in FonT 

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

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

Keywords: gst, inertia, disorder

# gst: an analogy between geometrical frustrations and nonreciprocal systems

<< A system is geometrically frustrated when its members cannot find a configuration that simultaneously minimizes all their interaction energies, (..). A nonreciprocal system is one whose members have conflicting, asymmetric goals, as exemplified by an ecosystem of predators and prey. >>️

<< Ryo Hanai (..) has identified a powerful mathematical analogy between those two types of dynamical systems. >>️

Peter Littlewood. Nonreciprocal Frustration Meets Geometrical Frustration. Physics 17, 32. Feb 26, 2024. 

https://physics.aps.org/articles/v17/32

Ryo Hanai. Nonreciprocal Frustration: Time Crystalline Order-by-Disorder Phenomenon and a Spin-Glass-like State. Phys. Rev. X 14, 011029. Feb 26, 2024. 

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011029

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

Keywords: gst, analogy, order, disorder, noise

# life: it’s time to admit that ...

<< For too long, scientists have been content in espousing the lazy metaphor of living systems operating simply like machines, (..) Yet, it’s important to be open about the complexity of biology — including what we don’t know — because public understanding affects policy, health care and trust in science.  “So long as we insist that cells are computers and genes are their code,” writes Ball, life might as well be “sprinkled with invisible magic”. But, reality “is far more interesting and wonderful”, as he explains in this must-read user’s guide for biologists and non-biologists alike. >>️

Denis Noble. It’s time to admit that genes are not the blueprint for life. Nature. 626, 254-255 (2024). Feb 5,  2024. 

https://www.nature.com/articles/d41586-024-00327-x

Philip Ball. How Life Works: A User’s Guide to the New Biology. Pan Macmillan (2024). 

https://www.panmacmillan.com/authors/philip-ball/42387

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

Keywords: life, disorder, fluctuations

FonT: this point of view, published in the 70s-80s, would have made a damned impression. 

# gst: transitions in disordered medium.

AA << study computationally the dynamics of forced, Brownian particles through a disordered system. As the concentration of mobile particles and/or fixed obstacles increase, (AA) characterize the different regimes of flow and address how clogging develops. >>️

AA << show that clogging is preceded by a wide region of anomalous transport, characterized by a power law decay of intermittent bursts. (..) this abnormal flow region is characterized by a coexistence between mobile and arrested particles, and their relative populations change smoothly as clogging is approached. >>

️

Sergi G. Leyva, Ignacio Pagonabarraga. Clogging transition and anomalous transport in driven suspensions in a disordered medium. Phys. Rev. E 109, 014618. Jan 31, 2024.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.109.014618

img:  https://twitter.com/PhysRevE/status/1753068208586711072   

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

Keywords: gst, transition, particle, disorder

# gst: intertwining order, disorder, and hierarchy

<< Nature hosts a wealth of materials showcasing intricate structures intertwining order, disorder, and hierarchy, delivering resilient multifunctionality surpassing perfect crystals or simplistic disordered materials. The engineering of such materials through nanoparticle assembly represents a burgeoning field, poised with potential to yield sustainable material systems rivaling or exceeding biological functionalities. >>

AA << review delineates the fundamental concept of complexity in the context of nanoscale materials. >>

Xiaoming Mao, Nicholas Kotov. Complexity, Disorder, and Functionality of Nanoscale Materials. arXiv: 2401.09567v1 [cond-mat.soft]. Jan 17, 2024. 

https://arxiv.org/abs/2401.09567

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

Keywords: nano, particle, order, disorder 

gst: actually and counterintuitively a coherent jump could generate disorder.

AA << consider a quantized version of a model for “random walk in random environment.” (..) For a ring geometry (a chain with periodic boundary condition) it features a delocalization-transition as the bias in increased beyond a critical value, indicating that the relaxation becomes underdamped. Counterintuitively, the effective disorder is enhanced due to coherent hopping. >>

Ben Avnit, Doron Cohen. Quantum walk in stochastic environment. Phys. Rev. E 108, 054111. Nov 7, 2023. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.108.054111

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

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

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

Keywords: gst, walk, random walk, quantum walk, qu-walk, jump, transition, disorder, chaos

# gst: emergence of chimeras driven by non-normality

<< The emergence of order in nature manifests in different phenomena, with synchronization being one of the most representative examples. >>️

<< Particular attention has been paid to the emergence of chimera states, where subsets of synchronized oscillations coexist with asynchronous ones. Such coexistence of coherence and incoherence is a perfect example where order and disorder can persist in a long-lasting regime. >>

<< Based on a symmetry-breaking mechanism, in this paper, (AA) shed light on the role that non-normality, a ubiquitous structural property of real networks, has in the emergence of several diverse dynamical phenomena, e.g., amplitude chimeras or oscillon patterns. >>️

<< Specifically, (they) demonstrate that the prevalence of source or leader nodes in networks leads to the manifestation of phase chimera states. >>️

Riccardo Muolo, Joseph D. O'Brien, et al. Persistence of chimera states and the challenge for synchronization in real-world networks. arXiv: 2306.00237v1 [nlin.PS]. May 31, 2023.

https://arxiv.org/abs/2306.00237

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

Keywords: gst, chimera, network, synchronization, swarm, noise, order, disorder, normal

# gst: even a tiny noise could self-induce new chimera patterns through stochastic resonance

<< Noise induced order in excitable systems has diverse manifestations, such as coherence resonance (CR) and stochastic resonance. In this context a less explored phenomenon is self-induced stochastic resonance (SISR). Unlike CR, SISR may arise away from the bifurcation threshold and the properties of the induced oscillations depend upon both the noise intensity and the time-scale separation factor. In this work, (AA) report a new chimera pattern in a network of coupled excitable units, namely the self-induced stochastic resonance chimera or SISR-chimera that originates from the SISR phenomenon. (AA) explore the detailed dynamics of the SISR-chimera in the parameter space using proper quantitative measures. (AA) have found that unlike CR chimera, the SISR-chimera pattern strongly depends upon the ratio of time scale and noise intensity. Therefore, this type of chimera pattern can be induced even for a tiny noise intensity if the time scale separation of the activator and inhibitor is large enough. >>️

Taniya Khatun, Tanmoy Banerjee. Genesis of chimera patterns through self-induced stochastic resonance. arXiv:2305.06824v1 [nlin.AO]. May 11, 2023. 

https://arxiv.org/abs/2305.06824

Also:  chimera, noise, disorder in  https://www.inkgmr.net/kwrds.html  

Keywords: gst, noise, disorder, chimera, self-induced stochastic resonance chimera 

# gst: influence of disorder on the spreading and entanglement properties of coined quantum walks.

AA << investigate the influence of disorder on the spreading and entanglement properties of coined quantum walks. Specifically, (AA) consider quantum walks on the line and explore the effects of quenched disorder in the coin operations. (They) find that coin disorder alters the usual ballistic transport properties of coined quantum walks considerably and yields an extremely slow dynamics with strong evidence for localization behavior. (They) investigate this slow dynamics by comparing different properties of the walker occupation probability with the standard Hadamard walk. (They) find that the walker distribution, and a number of properties associated with it, are significantly altered by the coin disorder. Special focus is given to the influence of coin disorder on entanglement properties. (AA) observe that generically, coin disorder decreases the coin-walker entanglement. The behavior of the entanglement properties further supports the premise that coin disorder induces localization in coined quantum walks. >>

Louie Hong Yao, Sascha Wald. Coined Quantum Walks on the Line: Disorder, Entanglement and Localization. arXiv: 2303.15978v1 [quant-ph]. doi: 10.48550/ arXiv.2303.15978. 28 Mar 28, 2023.

https://arxiv.org/abs/2303.15978

Also

Voli a casaccio. Notes. Oct 01, 2006. 

(quasi-stochastic poetry)

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

keyword 'disorder' in FonT

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

keyword 'disordine' in Notes 

(quasi-stochastic poetry)

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

keyword 'walk' | 'walking' in FonT

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

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

keyword 'passo lieve' | 'walk' | 'walking' in Notes

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=passo+lieve

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

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

Keywords: gst, disorder, quantum physics, walk, walking, coined quantum walks

# gst: slow dynamics of a interacting mobile impurity (in a bath of localized particles)

AA << investigate dynamics of a single mobile impurity immersed in a bath of Anderson localized particles and focus on the regime of relatively strong disorder and interactions. In that regime, the dynamics of the system is particularly slow, suggesting, at short times, an occurrence of many-body localization. Considering longer time scales, (AA) show that the latter is a transient effect and that, eventually, the impurity spreads sub-diffusively and induces a gradual delocalization of the Anderson insulator. The phenomenology of the system in the considered regime of slow dynamics includes a sub-diffusive growth of mean square displacement of the impurity, power-law decay of density correlation functions of the Anderson insulator and a power-law growth of entanglement entropy in the system. (AA) observe a similar regime of slow dynamics also when the disorder in the system is replaced by a sufficiently strong quasi-periodic potential. >>

Piotr Sierant, Titas Chanda, Maciej Lewenstein, Jakub Zakrzewski. Slow dynamics of a mobile impurity interacting with an Anderson insulator. arXiv: 2212.07107v1 [cond-mat.dis-nn]. Dec 14, 2022. 

https://arxiv.org/abs/2212.07107

Also

keyword 'particle' | 'quasiparticle' in FonT

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

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

keyword 'particelle' in Notes

(quasi-stochastic poetry)

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

Keywords: gst, particles, impurity, disorder, sub-diffusive growth, transition, entanglement entropy

# gst: apropos of transitions, disordered systems mimic genetic evolution.

<< A bacterial genome’s evolution under changing drug concentrations displays effects of memory formation and mimics how disordered solids respond to external forces. >>️

AA << simulate the effect on adaptation of an environment that is constantly changing. Using a model that describes how slow-moving disordered systems respond to external forces, (they) find that microbe evolution in changing drug concentrations exhibits hysteresis and memory formation. They use analytical methods and numerical simulations to connect these statistical physics concepts to bacterial drug resistance. >>️

AA << find that this behavior mimics that of disordered systems driven by external forces, such as ferromagnetic materials subjected to magnetic fields or amorphous materials subjected to a shearing force. They say that while their approach focuses on the evolution of drug resistance, the framework can be adapted to other problems in evolutionary biology that involve changing environmental parameters. >>

️

Rachel Berkowitz. Disordered Systems Mimic Genetic Evolution. Physics 15, s118. Sep 20, 2022. 

https://physics.aps.org/articles/v15/s118

Suman G. Das, Joachim Krug, Muhittin Mungan. Driven Disordered Systems Approach to Biological Evolution in Changing Environments. Phys. Rev. X 12, 031040. Sep 20, 2022.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.12.031040

Also

keyword 'disorder' in FonT

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

keyword 'disordine' in Notes

(quasi-stochastic poetry)

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

Keywords: gst, disorder, disordered systems, evolution, genetic evolution 

# gst: apropos of transitions, perspectives on viscoelastic flow instabilities; the 'porous individualism'

<< given the observation that disorder can suppress the transition to elastic turbulence in 2D porous media (..), it has been unclear whether and how this transition manifests in disordered 3D media — though elastic turbulence has been speculated to underlie the long-standing observation that the macroscopic flow resistance of an injected polymer solution can abruptly increase above a threshold flow rate in a porous medium, but not in bulk solution >>️

AA << found that the transition to unstable flow in each pore is continuous, arising due to the increased persistence of discrete bursts of instability above a critical value of the characteristic (Weissenberg no.) Wi; however, the onset value varies from pore to pore. This observation that single pores exposed to the same macroscopic flow rate become unstable in different ways provides a fascinating pore-scale analog of “molecular individualism” [P.  De Gennes, Molecular individualism. Science 276, 1999–2000 (1997)], in which single polymers exposed to the same extensional flow elongate in different ways; the authors therefore termed it “porous individualism”, although it is important to note that here, this effect is still at the continuum (not molecular) scale. Thus, unstable flow is spatially heterogeneous across the different pores of the medium, with unstable and laminar regions coexisting >>

AA << quantitatively established that the energy dissipated by unstable pore-scale fluctuations generates an anomalous increase in flow resistance through the entire medium that agrees well with macroscopic pressure drop measurements. >>

Sujit S. Datta, Arezoo M. Ardekani, et al. Perspectives on viscoelastic flow instabilities and elastic turbulence. arXiv: 2108.09841v1 [physics.flu-dyn]. Aug 22, 2021. 

https://arxiv.org/abs/2108.09841

Also

keyword 'transition' | 'transitional' in FonT

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

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

keyword 'transition' | 'transizion*' in Notes (quasi-stochastic poetry)

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

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

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

keywords: gst, droplet, fluctuations, disorder, instability, viscoelastic flow instability, turbulence, elastic turbulence, individualism, porous individualism, transition

# gst: apropos of disorder & fluctuations

a 'synthetic disorder & fluctuations' from these two blogs ... 

keyword 'disorder' in FonT 

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

keyword 'disordine' in Notes (quasi-stochastic poetry) 

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

keyword 'error' | 'fuzzy' | 'noise'  in FonT

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

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

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

keywords 'errore' | 'errori' in Notes (quasi-stochastic poetry)

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

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

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

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

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

keyword 'waves' in FonT 

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

keyword 'onda' in Notes 

(quasi-stochastic poetry) 

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

keyword 'gst' (General Sistem Theory) in FonT 

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

# gst: increase transport with disorder

<< Overcoming the detrimental effect of disorder at the nanoscale is very hard since disorder induces localization and an exponential suppression of transport efficiency. (AA) unveil novel and robust quantum transport regimes achievable in nanosystems by exploiting long-range hopping. (They) demonstrate that in a 1D disordered nanostructure in the presence of long-range hopping, transport efficiency, after decreasing exponentially with disorder at first, is then enhanced by disorder  [disorder-enhanced transport regime] until, counterintuitively, it reaches a disorder-independent transport regime, persisting over several orders of disorder magnitude in realistic systems. >>️

Nahum C. Chávez, Francesco Mattiotti, et al. Disorder-Enhanced and Disorder-Independent Transport with Long-Range Hopping: Application to Molecular Chains in Optical Cavities. Phys. Rev. Lett. 126, 153201. Apr 12,  2021.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.126.153201

Horacio M. Pastawski. Driving Transport with High Disorder. Physics 14, 57. Apr 12, 2021. 

https://physics.aps.org/articles/v14/57

Also

keyword 'disorder' in FonT

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

keyword 'disordine' in Notes (quasi-stochastic poetry)

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

# gst: disorder can induce and modulate topological structures

 << One of the boons of topological insulators is that their conducting edge states are protected from disorder in the material’s structure. Turn up the disorder too much, however, and these topological features are usually lost. In 2018, experiments demonstrated the opposite behavior: in so-called topological Anderson insulators (TAIs), the addition of disorder can generate protected edge states, turning a trivial insulator into a topological one. Now, a team (..) reports a new type of TAI realized in a photonic crystal. Their experiments show that the crystal exhibits a wealth of topological phenomena that hadn’t been seen previously. >> 

Matteo Rini. Let Disorder Dictate Topology. Physics 13, s123. Sep 24, 2020. 

https://physics.aps.org/articles/v13/s123    

 AA << directly observe the disorder-induced topological phase transition from a trivial insulator to a TAI with robust chiral edge states. (They) also demonstrate topological heterostructures that host edge states at interfaces between domains with different disorder parameters. >> 

Gui-Geng Liu, Yihao Yang, et al. Topological Anderson Insulator in Disordered Photonic Crystals. Phys. Rev. Lett. 125, 133603. Sep 24, 2020.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.133603