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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 11 ottobre 2023

# phys: a quantum gravity hypothesis on infalling matter (hunting for extreme Kerr black holes)

 << Quantum gravity refers to a group of theories—string theory, for example—that aims to reconcile the microscopic world of quantum physics with the macroscopic world of general relativity. >> 

 << Now theoretical work by Grant N.  Remmen (et al) shows that celestial objects called extremal Kerr black holes are highly sensitive to quantum gravity. >> 
 
  << A Kerr black hole is a rotating, electrically neutral black hole. It is said to be extremal if it has the highest possible angular momentum that is compatible with its mass.  Extremal Kerr black holes have yet to be detected, but many theories predict their existence. >> 
 
 They << point out that quantum corrections to general relativity would provide specific contributions to a quantity called the effective action, which describes the dynamics of a gravitational field. (..) under quantum gravity, the event horizon would develop curvature singularities—regions where the gravitational field is infinitely strong. >> 
 
 << the next step is to hunt for extremal Kerr black holes and to try to detect these curvature singularities through their effect on infalling matter. >> 

Ryan Wilkinson. New Physics Magnified in Spinning Black Holes. Physics 16, s117. Aug 31, 2023.

Gary T. Horowitz, Maciej Kolanowski, Grant N. Remmen, Jorge E. Santos. Extremal Kerr Black Holes as Amplifiers of New Physics. Phys. Rev. Lett. 131, 091402. Aug 31, 2023.

Also: Ingrid Fadelli. Theoretical study shows that Kerr black holes could amplify new physics. Phys.org. Sep 22, 2023. 

Also: astrophysics, black hole, in: https://www.inkgmr.net/kwrds.html

Keywords: astrophysics, black holes



mercoledì 4 ottobre 2023

# life: a proposito di '1or2achoos' (da Wuhan (?)), qui la cronologia

a proposito di '1or2achoos' (da Wuhan (?)), qui la cronologia di inizio dei 6 flu|covid che ho contratto dal gen2020 ad oggi con i relativi tempi di 'smorzamento' dell'infezione, trattati nebulizzando una miscela di alcool e H2O2 ( https://flashontrack.blogspot.com/2022/07/life-aproposito-di-1or2achoos-da-wuhan.html )

(1) 2020.04.11-16:04 ~12h (non vaccinato)
(2) 2021.09.01-07:40 ~12h (non vaccinato)
(3) 2022.06.11-08:26 18-36h (+1mese post vaccino, 3dosi)
(4) 2022.12.24-07:52 ~24h 
(5) 2023.02.28-12:09 ~24h 
(6) 2023.04.08-09:32 24-36h 

I tempi necessari per 'spegnere' questi  flu|covid sono tutti notevolmente inferiori (~80%) rispetto alle pregresse forme di flu che ho contratto delle quali ho memoria.

Invece non ho altre parole da aggiungere per commentare i diversi argomenti associabili a '1or2achoos' dal febbraio 2020 ad oggi.

Potrei (e.g. expectedepidemic, lockdown, greenpass, indicatori, statistiche, accademieacucciabili, sadichepredazioni, bucodibilancio, pastroky, ...) nelle bizzarre forme della poetica quasistocastica ( https://inkpi.blogspot.com/ ), ma mi astengo.

Anche: "Ricordo che quando si era ragazzi". in: "il pino di takata matsubara". Notes. Apr 1, 2011. https://inkpi.blogspot.com/2011/04/2157-il-pino-di-takata-matsubara.html

Anche: "e Da-Li' si sparse pell'aere". in: "cracker tendenziali". Notes. Apr 4, 2008. https://inkpi.blogspot.com/2008/04/cracker-tendenziali-around-matter.html

Anche: "in attesa del beffardo tsunami". in: "onda di carambola". Notes. Nov 29, 2004. 

Anche: "aproposito di '1or2achoos' (da Wuhan (?)) ...". FonT. Jul 13, 2022. https://flashontrack.blogspot.com/2022/07/life-aproposito-di-1or2achoos-da-wuhan.html

Anche: 1or2achoos, sars, covid, virus, pastroky, in: 

Keywords: life, virus, flu, coronavirus,  sarscov2, covid19, 1or2achoos, mask



lunedì 2 ottobre 2023

# gst: anisotropic active depletion around a self-propelled non-interactive colloids; three characteristic states could be identified.

<< Active colloids in a bath of inert particles of smaller size cause anisotropic depletion. >>️

Here AA << combine mesoscale hydrodynamic simulation as well as theoretical analysis to examine the physical origin for the active depletion around a self-propelled noninteractive colloid. >>️

Their << results elucidate that the variable hydrodynamic effect critically governs the microstructure of the depletion zone. Three characteristic states of anisotropic depletion are identified, depending on the strength and stress of activity. >>️

<< Furthermore, (AA) demonstrate that such depletion in nonequilibrium results in various clusters with ordered organization of squirmers, which follows a distinct principle contrary to that of the entropy scenario of depletion in equilibrium. >>
Lijun Dai, Haixiao Wan, et al. Hydrodynamic Anisotropy of Depletion in Nonequilibrium. Phys. Rev. Lett. 131, 134002. Sep 27, 2023. 

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

Keywords: gst, particles, colloids, depletion, squirmers, self-propulsion systems


sabato 30 settembre 2023

# gst: wandering domains: a hypothetical scenario with bounded orbits.

<< A significant open question in transcendental dynamics asks if it is possible for a point, and thus all points, of a wandering domain to have a bounded orbit. >>

<< In other words, is there a transcendental entire function f with a wandering domain U such that its forward orbit, U_n≥0 f^n(U), is bounded? >>

AA << give a partial answer to this question by constructing an example of a such a wandering domain U which has a nearly bounded orbit; >>

<< In other words, the set of natural numbers n for which f^n(U) is contained in D has upper (and lower) natural density one. >>

<< This is in particularly strong contrast to all existing examples of wandering domains, for which the quantity (..) is equal to zero for any choice of bounded domain D. >>

Leticia Pardo-Simon, David J. Sixsmith. Wandering domains with nearly bounded orbits. arXiv: 2307.16682v1 [math.DS]. Jul 31, 2023. 

Also: Unbounded fast escaping wandering domains. https://arxiv.org/abs/2210.13350 ; Escaping sets of continuous functions. https://arxiv.org/abs/1601.04010 


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

Keywords: gst, wandering domain, escape 


giovedì 28 settembre 2023

# gst: reconfiguration and oscillations of sheets subject to vortex

<< The dynamics of a thin low-density polyethylene sheet subject to periodic forcing due to Bénard-Kàrmàn vortices in a long narrow water channel is investigated here. In particular, the time-averaged sheet deflection and its oscillation amplitude are considered. >>

<< The former is first illustrated to be well-approximated by the static equilibrium between the buoyancy force, the elastic restoring force, and the profile drag based on the depth-averaged water speed. >>

AA << observations also indicate that the presence of upstream vortices hinder the overall reconfiguration effect, well-known in an otherwise steady flow. For the sheet-tip oscillations, a simple model based on a torsional-spring-mounted flat plate correctly captures the measured tip amplitude δb over a wide range of sheet physical properties and flow conditions. >>

<< Furthermore, a rich phenomenology of structural dynamics including vortex-forced-vibration, lock-in with the sheet natural frequency, and flow-induced vibration due to the sheet wake, multiple-frequency, and modal response is reported. >>
J. John Soundar Jerome, Yohann Bachelier, et al. Reconfiguration and oscillations of a vertical, cantilevered sheet subject to vortex shedding behind a cylinder. Phys. Rev. Fluids 8, 093801. Sep 15, 2023. 


Keywords: gst, sheet, vortex, Benard-Karman vortices