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

martedì 23 aprile 2024

# gst: Lévy flights and Lévy walks under stochastic resetting.

<< Stochastic resetting is a protocol of starting anew, which can be used to facilitate the escape kinetics. (AA)  demonstrate that restarting can accelerate the escape kinetics from a finite interval restricted by two absorbing boundaries also in the presence of heavy-tailed, Lévy-type, α
-stable noise. However, the width of the domain where resetting is beneficial depends on the value of the stability index α determining the power-law decay of the jump length distribution. For heavier (smaller α) distributions, the domain becomes narrower in comparison to lighter tails. >>

<< Additionally, (AA) explore connections between Lévy flights (LFs) and Lévy walks (LWs) in the presence of stochastic resetting. First of all, (They) show that for Lévy walks, the stochastic resetting can also be beneficial in the domain where the coefficient of variation is smaller than 1. Moreover, (They) demonstrate that in the domain where LWs are characterized by a finite mean jump duration (length), with the increasing width of the interval, the LWs start to share similarities with LFs under stochastic resetting. >>️

Bartosz Żbik, Bartłomiej Dybiec. Lévy flights and Lévy walks under stochastic resetting. Phys. Rev. E 109, 044147. April 22, 2024.

Also: keyword Lévy in FonT

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

Keywords: gst, escape, noise, stochastic resetting, Lévy


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



giovedì 8 febbraio 2024

# life: mimesis, ambiguity, noise, when an entity is master of disguise.

<< At every stage in their lives, from egg to adult, leaf and stick insects prove to be prey that can trick their predators. >>️

Allie Yang. These insects are masters of disguise—even before hatching. nationalgeographic.com. Oct 17, 2023.

Also: mimesis, in Notes (quasi-stochastic poetry)


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

Keywords: mimesis, disguise, ambiguity, noise, metamorphosis, two-faced Janus


sabato 16 dicembre 2023

# gst: correlated noise and critical dimensions.

<< In equilibrium, the Mermin-Wagner theorem prohibits the continuous symmetry breaking for all dimensions d≤2. In this work, (AA) discuss that this limitation can be circumvented in nonequilibrium systems driven by the spatiotemporally long-range anticorrelated noise. >>

<< results suggest that the critical dimensions increase when the noise is positively correlated in space and time and decrease when anticorrelated. (AA)  also report that the spherical model with the correlated noise shows the hyperuniformity and giant number fluctuation even well above the critical point. >>️

Harukuni Ikeda. Correlated noise and critical dimensions. Phys. Rev. E 108, 064119. Dec 13, 2023.

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

Keywords: gst, noise, fluctuations


sabato 21 ottobre 2023

# gst: local elastic properties of strongly disordered matter

<< The local elastic properties of strongly disordered material are investigated using the theory of correlated random matrices. A significant increase in stiffness is shown in the interfacial region, the thickness of which depends on the strength of disorder. It is shown that this effect plays a crucial role in nanocomposites, in which interfacial regions are formed around each nanoparticle. >>️

D. A. Conyuh, A. A. Semenov, Y. M. Beltukov. Effective elastic moduli of composites with a strongly disordered host material. Phys. Rev. E 108, 045004. Oct 20, 2023. 

Also: elastic, noise, particle, nano, in https://www.inkgmr.net/kwrds.html

Keywords: gst, elastic, noise, particle, nano


martedì 17 ottobre 2023

# game: noise-induced Parrondo's paradox in discrete-time qu-walks

<< Parrondo's paradox refers to the apparently paradoxical effect whereby two or more dynamics in which a given quantity decreases are combined in such a way that the same quantity increases in the resulting dynamics. >>

AA << show that noise can induce Parrondo's paradox in one-dimensional discrete-time quantum walks with deterministic periodic as well as aperiodic sequences of two-state quantum coins where this paradox does not occur in the absence of noise. >>️

Zbigniew Walczak, Jarosław H. Bauer. Noise-induced Parrondo's paradox in discrete-time quantum walks. Phys. Rev. E 108, 044212. Oct 11, 2023.

Also: parrondo, walk, noise, in: https://www.inkgmr.net/kwrds.html

Keywords: games, parrondo, walk, noise




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


mercoledì 6 settembre 2023

# gst: chimera resonance, in analogy with the effects of stochastic and coherence resonance


AA << explore numerically the impact of additive Gaussian noise on the spatio-temporal dynamics of ring networks of nonlocally coupled chaotic maps. >>
<<  It is shown that the coupling strength range can be the widest at a certain optimum noise level at which chimera states are observed with a high probability for a large number of different realizations of randomly distributed initial conditions and noise sources. >>

<< This phenomenon demonstrates a constructive role of noise in analogy with the effects of stochastic and coherence resonance and may be referred to as chimera resonance. >>️

Elena Rybalova, Vasilii Nechaev, Eckehard Schöll, Galina Strelkova. Chimera resonance in networks of chaotic maps. arXiv:2307.00006v2 [cond-mat.dis-nn]. Jul 5, 2023.

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

Keywords: gst, chimera, noise, chaos, network, chimera resonance





lunedì 14 agosto 2023

# gst: rich behaviors from stochastic walking with variable long jumps.


AA << propose a generalized model where the random walker takes stochastic jumps of lengths proportional to its present position with certain probability, otherwise it makes forward and backward jumps of fixed (unit) length with given rates. The model exhibits a rich stochastic dynamic behavior.  (AA) obtain exact analytic results for the first two moments of the walker's displacement and show that a phase transition from a diffusive to superdiffusive regime occurs if the stochastic jumps of lengths that are twice (or more) of its present positions are allowed. This phase transition is accompanied by a reentrant diffusive behavior. >> 

Upendra Harbola. Stochastic walker with variable long jumps. Phys. Rev. E 108, 014135. July 28, 2023. 

Also: walk, noise, fluctuations, dance,  in: https://www.inkgmr.net/kwrds.html

Keywords: gst, walks, random walks, noise, fluctuations



venerdì 11 agosto 2023

# gst: stochastic resonance mediated by optimal noise level values; transport of colloidal particles induced by substrate concentration oscillations.


AA << show the existence of a  stochastic resonant regime in the transport of active colloidal particles under confinement. The periodic addition of substrate to the system causes the spectral amplification to exhibit a maximum for an optimal noise level value. The consequence of this is that particles can travel longer distances with lower fuel consumption. The stochastic resonance phenomenon found allows the identification of optimal scenarios for the transport of active particles, enabling them to reach regions that are otherwise difficult to access, and may therefore find applications in transport. >>️

J. D. Torrenegra-Rico, A. Arango-Restrepo, J. M. Rubi. Optimal transport of active particles induced by substrate concentration oscillations. Phys. Rev. E 108, 014134. July 28, 2023.


Also: particle, colloids, noise, in:  https://www.inkgmr.net/kwrds.html

Keywords: gst, particle, colloids, noise, stochastic resonance, substrate oscillation

sabato 5 agosto 2023

# gst: tipping in a low-dimensional model of a (tropical) cyclone.


 <<Tipping is the rapid, and often irreversible, change in the state of a system [Ashwin P. et al (2017)] >> 

AA << present a case study of both rate and noise-induced tipping between the stable states, relating to the destabilization or formation of a tropical cyclone. While the stochastic system exhibits transitions both to and from the non-storm state, noise-induced tipping is more likely to form a storm, whereas rate-induced tipping is more likely to be the way a storm is destabilized, and in fact, rate-induced tipping can never lead to the formation of a storm when acting alone. For rate-induced tipping acting as a destabilizer of the storm, a striking result is that both wind shear and maximal potential velocity have to increase, at a substantial rate, in order to effect tipping away from the active hurricane state. For storm formation through noise-induced tipping, (AA) identify a specific direction along which the non-storm state is most likely to get activated. >> 

Katherine Slyman, John A. Gemmer, et al. Tipping in a Low-Dimensional Model of a Tropical Cyclone. arXiv: 2307.15583v1 [math.DS]. Jul 28, 2023.
 
Also: vortex, instability, noise, in https://www.inkgmr.net/kwrds.html

Keywords: gst, climate, storm, cyclone, vortex, noise, tipping, noise-induced tipping



martedì 18 luglio 2023

# gst: evolution of survivors compared to discrete vs continuous noise


<< Environmental variations can significantly influence how populations compete for resources, and hence shape their evolution. Here, (AA) study population dynamics subject to a fluctuating environment modeled by a varying carrying capacity changing continuously in time according to either binary random switches, or by being driven by a noise of continuous range. >>

<< the slow strain fixation probability can be greatly enhanced for a continuously varying environment compared to binary switches, even when the first two moments of the carrying capacity coincide. >>️

Ami Taitelbaum, Robert West, et al. Evolutionary dynamics in a varying environment: Continuous versus discrete noise. Phys. Rev. Research 5, L022004. April 4, 2023. 


Keywords: gst, evolution, noise, discrete vs continuous noise


sabato 15 luglio 2023

# brain: the sense of hearing, the sense of silence.


<< Do we only hear sounds? Or can we also hear silence? These questions are the subject of a centuries-old philosophical debate between two camps: the perceptual view (we literally hear silence), and the cognitive view (we only judge or infer silence). >>

<< In all cases (concerning seven experiments), silences elicited temporal distortions perfectly analogous to their sound-based counterparts, suggesting that auditory processing treats moments of silence the way it treats sounds. Silence is truly perceived, not merely inferred. >>️
Rui Zhe Goh, Ian B. Phillips, Chaz Firestone. The perception of silence. 
PNAS. 120 (29) e2301463120. Jul 10, 2023. 

Roberto Molar Candanosa. The sound of silence? Researchers prove we can  hear it. Johns Hopkins University - HUB. Jul 11, 2023. 

Researchers Prove We Hear the 
Sound of Silence. Jul 10, 2023. 

Also: silence, pause, sound, noise, perception, brain, in https://www.inkgmr.net/kwrds.html 

Keywords:  brain, perception, sound, noise, pause, silence


giovedì 22 giugno 2023

# gst: the effects of order- disorder on a system of swarmalators that move on a one-dimensional ring.


<< Swarmalators are phase oscillators that cluster in space, like fireflies flashing on a swarm to attract mates. >>

<< In this work, (AA) explore the effects of disorder induced by phase frustration on a system of Swarmalators that move on a one-dimensional ring. >>

They find << numerically and analytically, the ordered and disordered states that emerge in the system. The active states, not present in the model without disorder, resemble states found previously in numerical studies for the 2D Swarmalators system. One of these states, in particular, shows similarities to turbulence generated in a flattened media. (AA) show that all ordered states can be generated for any values of the coupling constants by tuning the phase frustration parameters only. Moreover, many of these combinations display multi-stability. >>️

Joao U.F. Lizarraga, Marcus A.M. de Aguiar. Sakaguchi Swarmalators. arXiv: 2305.08615v1 [nlin.PS]. May 15, 2023. 

Also:  'swarm', 'turbulence', 'noise', 'particle' in: https://www.inkgmr.net/kwrds.html

Keywords: gst, swarm, turbulence, noise, particle




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 




lunedì 24 aprile 2023

# gst: emergent organization and polarization due to active fluctuations.


AA << introduce and study a model of active Brownian motion with multiplicative noise describing fluctuations in the self-propulsion or activity. (They) find that the standard picture of density accumulation in slow regions is qualitatively modified by active fluctuations, as stationary density profiles are generally not determined only by the mean self-propulsion speed landscape. As a result, activity gradients generically correlate the particle self-propulsion speed and orientation, leading to emergent polarization at interfaces pointing either towards dense or dilute regions depending on the amount of noise in the system.  >>
Benoit Mahault, Prakhar Godara, Ramin Golestanian. Emergent organization and polarization due to active fluctuations. Phys. Rev. Research 5, L022012. April 12, 2023. 

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

Keywords: gst, particle, organization, polarization, fluctuations, noise, self-propulsion, self-assembly 



mercoledì 21 dicembre 2022

# gst: apropos of transitions, rich behaviors from chimeras or solitary states to traveling waves

AA << study numerically the spatiotemporal dynamics of a ring network of nonlocally coupled nonlinear oscillators, each represented by a two-dimensional discrete-time model of the classical van der Pol oscillator. >>
<< It is shown that the discretized oscillator exhibits a richer behavior, combining the peculiarities of both the original system and its own dynamics. Moreover, a large variety of spatiotemporal structures is observed in the network of discrete van der Pol oscillators when the discretization parameter and the coupling strength are varied. Such regimes as the coexistence of multichimera state/traveling wave and solitary state are revealed for the first time and studied in detail. >>
<< It is established that the majority of the observed chimera/solitary states, including the newly found ones, are transient towards the purely traveling wave mode. The peculiarities of the transition process and the lifetime (transient duration) of the chimera structures and the solitary state are analyzed depending on the system parameters, observation time, initial conditions, and influence of external noise. >>

Elena Rybalova, Sishu Muni, Galina Strelkova. Transition from chimera/solitary states to traveling waves. arXiv: 2212.07990v1 [nlin.AO]. Dec 15, 2022. 

Also

keyword 'transition' | 'transitional' in FonT



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




keyword 'waves' in FonT


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


Keywords: gst, behavior, van der Pol oscillator, transition, chimera state, solitons, solitary state, waves, noise









lunedì 19 dicembre 2022

# gst: behavior of microswimmers in a vortex with translational and rotational noise

AA << propose a theoretical model to investigate the dynamics of elongated microswimmers in elementary vortices, namely active particles in two- and three-dimensional rotlets. A deterministic model first reveals the existence of bounded orbits near the centre of the vortex and unbounded orbits elsewhere. (AA) further discover a conserved quantity of motion that allows (..) to map the phase space according to the type of the orbit (bounded vs unbounded). (They) next introduce translational and rotational noise into the system. Using a Fokker--Planck formalism, (AA) quantify the quality of trapping near the centre of the vortex by examining the probability of escape and the mean time of escape from the region of deterministically bounded orbits. (AA) finally show how to use these findings to formulate a prediction for the radius of the depletion zone, which compares favourably with the experiments of Sokolov and Aranson (2016). >>

Ivan Tanasijevic, Eric Lauga. Microswimmers in vortices: Dynamics and trapping. arXiv: 2211.05866v1 [physics.bio-ph].  Nov 10, 2022. 

Also

'microswimmers' in FonT 

Keywords: gst, behav, translation,  rotation, trapping, noise, swimmer, swimming,  microswimmers, fluid dynamics, vortex, vortices, vortexes, vorticity




domenica 23 ottobre 2022

# jazz: Eastside Romp. Jeff Parker (gui), Eric Revis (b), Nasheet Waits (d).

<< In May 2016, guitarist Jeff Parker, double bassist Eric Revis, and drummer Nasheet Waits spent a single day recording in a Pasadena studio. The seven tunes they cut appear on Eastside Romp. Mixed in 2018, it sat on a shelf for four more years. (..) No one except the creators know why it took six long years for this relaxed yet canny set to arrive, but its appearance adds immeasurably to the mystique and inventive creativity of these three musicians. >> Thom Jurek (T.J.)

- Drunkard's Lullaby
<< "Drunkard's Lullaby" is a group improvisation, laden with guitar effects, knotty bass vamps, and dialogic conversation between snare, hi-hat, and kick drum. Parker's abstracted soloing is saturated in distortion, and it short-circuits, staggering his already jagged lines, creating a barely restrained sense of power. The rhythm section intersects and interlocks in detailed, propulsive conversation as the guitar travels afield, adding more frenetic yet glitchy notes and layers of feedback. >> (T.J.)

- Wait
<< "Wait," the album's longest cut, was composed by the guitarist. It commences as a dirge led by Revis playing vamped chords. He establishes a circular vamp as Parker points at his changes and Waits dances limpidly on his tom-toms in 4/4. The languid lyric line crisscrosses post-bop, Spanish-tinged modalism, and blues. Parker moves between melody and angular improv as his bandmates respond with empathy, highlighting and expanding the reach of his labyrinthine harmonic lines. As a perfect complement, Waits offers a studio version of his oft-performed nugget "Between Nothingness and Infinity." Paraphrasing the title of 1973's live Mahavishnu Orchestra album Between Nothingness & Eternity, he frames a musical narrative that emerges directly out of Parker's deeply moving ballad-esque playing, adding textural airiness, rhythmic spaciousness, and harmonic depth to its melody. >> (T.J.)

- Similar Limits 
<< Opener "Similar Limits" is the set's only cover. Composed by the late alto saxophonist Marion Brown, it originally appeared on 1967's Porto Novo. The trio keep the iconic, Monk-esque intro after a brief roll from Waits. Parker and Revis play the staggered melodic intro as Waits rolls, fills, and accents all over the kit. As the bassist expands the tune's harmonic reach, Parker explores the underside with great sensitivity and swing. >> (T.J.)️

Jeff Parker, Eric Revis, Nasheet Waits. 
Drunkard's Lullaby, Wait, Similar Limits.
Eastside Romp.  Rogue Art 0113 (2022). 

Also

'jazz' | 'jazzy' | 'funky' |  in FonT (twitter)


'jazz' in Notes 
(quasi-stochastic poetry)









lunedì 10 ottobre 2022

# gst: apropos of transitions, escape inside a noisy layered system

<< Noisy layered systems can exhibit amplified fluctuation patterns depending on their connectivity. Here (AA) showed that noise originally injected in one layer may induce faster basin escape in connected layers. This is both due to the amplification of the noise amplitude and the system specific correlations that the noise acquire while going through the first layer. Indeed, (..) one sees that the noise in the second is correlated in both space and time with clear dependence on the network structure. For networks with low algebraic connectivity, (AA) numerically showed that the first escape time is shorter in the two cases where (i) fluctuations are amplified in the second layer and (ii) noise in the second layer is rescaled in order to have the same variance in both layers. While point (i) is rather intuitive, i.e. larger fluctuations lead to shorter first escape times, point (ii) is more involved. Indeed, this indicates that noise with spatial and temporal correlations (..) selects directions that enable faster exits from the initial basin of attraction. >>

Melvyn Tyloo. Faster network disruption from layered oscillatory dynamics. arXiv: 2210.01180v1 [nlin.AO]. Oct 3, 2022. 

Also

keyword 'escape' in FonT


keyword 'escape' | 'fuga' in Notes 
(quasi-stochastic poetry)



Keywords: gst, transitions, escape, noise, noisy layered systems