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Visualizzazione post con etichetta disorder. Mostra tutti i post
Visualizzazione post con etichetta disorder. Mostra tutti i post

martedì 30 aprile 2024

# 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. 

Also: inertia, disorder, in FonT 



Keywords: gst, inertia, disorder






giovedì 29 febbraio 2024

# 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. 

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

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

Keywords: gst, analogy, order, disorder, noise



sabato 17 febbraio 2024

# 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. 

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

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. 


sabato 3 febbraio 2024

# 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.


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

Keywords: gst, transition, particle, disorder


sabato 27 gennaio 2024

# 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. 

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

Keywords: nano, particle, order, disorder 




giovedì 16 novembre 2023

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. 

AlsoVoli a casaccio. Notes (quasi-stochastic poetry). Oct 01, 2006.

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


sabato 14 ottobre 2023

# 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.

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

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


venerdì 26 maggio 2023

# 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. 

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

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




venerdì 31 marzo 2023

# 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.

Also

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

keyword 'disorder' in FonT

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

keyword 'walk' | 'walking' in FonT


keyword 'passo lieve' | 'walk' | 'walking' in Notes
(quasi-stochastic poetry)



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



martedì 20 dicembre 2022

# 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. 

Also

keyword 'particle' | 'quasiparticle' in FonT



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


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





venerdì 4 novembre 2022

# 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. 

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.

Also

keyword 'disorder' in FonT

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

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



sabato 30 ottobre 2021

# 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. 



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

mercoledì 6 ottobre 2021

# gst: apropos of disorder & fluctuations

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

keyword 'disorder' in FonT 

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

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



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


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


keyword 'waves' in FonT 

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

keyword 'gst' (General Sistem Theory) in FonT 





sabato 24 aprile 2021

# 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.


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



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






martedì 22 dicembre 2020

# 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. 


 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.