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giovedì 22 settembre 2022

# life: apropos of quasi-stochastic (bizarre) landscapes in high-dimension, a case of double RAG-time inside a black hole with vortices

Here a hypotetical bizarre scenario of coexistence of double RAG-time (RAG: Ralph, Al, George) inside a black hole with vortices:

(1) 
Maurizio Belpietro.Sorprese in vista. Occhio alla strana coppia Conte D'Alema. La verità. anno vii n 258 pg 1. 19 set 2022.


(2) 

Andrea Pertici. Un soccorso centrista alla maggioranza dei due terzi?  
huffingtonpost.it. 18 Set 2022  17:08


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

keyword 'RAG' in FonT

black holes (as Q-ball-type saturons) could admit multi-vortex dynamics.
FonT. Sep 19, 2022.  

PS: really intriguing the image of a black hole with vortices ...

Keywords: life, jazz, RAG-time, RAGtime, black hole, vortex, vortices, vortexes, vorticity



martedì 20 settembre 2022

# gst: multiple external fields can modulate confined active particles

AA << analyze a dilute suspension of active particles confined between walls and subjected to fields that can modulate particle speed as well as orientation. Generally, the particle distribution is different in the bulk compared to near the walls. In the bulk, particles tend to accumulate in the regions of low speed, but in the presence of an orienting field, particles rotate to align with the field and accumulate downstream in the field direction. At the walls, particles tend to accumulate pointing into the walls and thereby exert pressure on walls. But the presence of strong orienting fields can cause the particles to reorient away from the walls >>

<< The pressure at the walls depends on the wall separation and the field strengths. This work demonstrates how multiple fields with different functionalities can be used to control active matter under confinement. >>️

Vaseem A. Shaik, Zhiwei Peng, et al. Confined active matter in external fields. arXiv:2208.09797v1 [cond-mat.soft]. Aug 21, 2022. https://arxiv.org/abs/2208.09797 

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keyword 'particle' | 'quasiparticle' in FonT



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


Keywords: gst, particle, particle control







lunedì 19 settembre 2022

# astro: black holes (as Q-ball-type saturons) could admit multi-vortex dynamics

<< Theoretical physicists argue that black holes admit vortex structures >>

Img << Sketch of a black hole endowed with multiple vortices. Colors denote the orientation, with the associated trapped magnetic field lines in black. Credit: Dvali et al. >>️

<< Recently, a new quantum framework for black holes, namely in terms of Bose-Einstein condensates of gravitons (the quanta of gravity itself), has been introduced, (..) Up until our article was published, rotating black holes have not been thoroughly studied within this framework. However, they might not only exist, but also be the rule rather than the exception. >> Florian Kühnel. 
Ingrid Fadelli. Theoretical physicists argue that black holes admit vortex structures. Phys.org. Sep 09, 2022. 

AA << argue that black holes admit vortex structure. This is based both on a graviton-condensate description of a black hole as well as on a correspondence between black holes and generic objects with maximal entropy compatible with unitarity, so-called saturons. (They) show that due to vorticity, a Q-ball-type saturon of a calculable renormalizable theory obeys the same extremality bound on the spin as the black hole. Correspondingly, a black hole with extremal spin emerges as a graviton condensate with vorticity. (..) Next, (AA) show that in the presence of mobile charges, the global vortex traps a magnetic flux of the gauge field. This can have macroscopically observable consequences. >>
Gia Dvali, Florian Kuhnel, Michael Zantedeschi. Vortices in Black Holes. Phys. Rev. Lett. 129, 061302. Aug 3, 2022.  

Also

keyword 'black hole' in FonT  

Keywords: astro, astrophysics, black hole, rotating black hole, vortex, vorticity








giovedì 15 settembre 2022

# gst: solitons as 'emergent elastic objects with spatially dependent stiffness'

<< Since the 1950s, topological solitons have been used to describe elementary particles and particle-like field configurations that appear in systems ranging from subatomic to cosmological scales. Particles are topologically protected, for which transitions to states with different topological charges are restricted. However, formation and annihilation of solitons are universal in almost all branches of physics, which implies that topological protection collapses at certain condition unrevealed. >>

<< Here, (AA) show that solitons can be regarded as emergent elastic objects with spatially dependent stiffness, and a second-order topological phase transition initiates at its softened points, i.e., points with a vanishing eigenvalue of the emergent stiffness matrix. >>
Yangfan Hu. Emergent elasticity and topological stability of solitons. arXiv: 2208.14916v1 [nlin.PS]. Aug 31, 2022. 

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'Second-order phase transitions

keyword 'solitons' in FonT

Keywords: gst, solitons, transition, phase_transition







martedì 13 settembre 2022

# gst: "birds of a feather flock together", the swarmalators

<< Swarmalators have emerged as a new paradigm for dynamical collective behavior of multi-agent systems due to the interplay of synchronization and swarming that they inherently incorporate. Their dynamics have been explored with different coupling topologies, interaction functions, external forcing, noise, competitive interactions, and from other important viewpoints. Here (AA) take a systematic approach and review the collective dynamics of swarmalators analytically and/or numerically. Long-term states of position aggregation and phase synchronization are revealed in this perspective with some future >>️

Gourab Kumar Sar, Dibakar Ghosh. Dynamics of swarmalators: A pedagogical review. arXiv: 2208.14803v1 [nlin.AO]. Jul 25, 2022. Europhysics Letters 139, 53001. 
doi: 10.1209/ 0295-5075/ac8445. 

Also

Keyword 'swarm' in FonT


Keywords: gst, behavior, collective behavior, self-organization, synchronization, spontaneous synchronization, swarm, swarmalators.


lunedì 12 settembre 2022

# gst: a backflipping behavior of air bubbles when they collide with a tilted surface

AA << observe that air bubbles exhibit a backflipping behavior when they collide with a tilted surface. >>

<< Particle image velocimetry reveals that the backflipping behavior is caused by wake-induced circulation around the bubble, which applies a lift force on the bubble. >>

<< The theoretical results are in good agreement with the experiments confirming the key role of the wake-induced lift force in backflipping. >>

Alireza Hooshanginejad, Anuj Baskota, Sunghwan Jung. Backflipping motion of air bubbles colliding with a tilted wall. arXiv: 2208.14486v1 [physics.flu-dyn]. Aug 30, 2022.
Also

keyword "bubble" in FonT

keyword "bolla" | "bolle" in Notes (quasistochastic-poetry)

Keywords: gst, bubble, behavior, backflipping behavior, oblique collisions






giovedì 8 settembre 2022

# behav: cry / not cry, babe ... POMC neurons modulate the crying behavior of pups (among mice)


<< Infants cry when separated from their mothers. Here, (AA) show that POMC (pro-opiomelanocortin) neurons in the arcuate nucleus of the hypothalamus—via ß-endorphin production and signaling—modulate the crying behavior of mouse pups. The effect of POMC neurons on vocal behavior depends on the expression of µ-opioid receptors, the main receptor for ß-endorphin. Thus, POMC neurons in the hypothalamus modulate infant cry through opioid signaling. >>️

Gabriela M. Bosque Ortiz, Marcelo O. Dietrich. POMC neurons modulate infant vocalizations through opioid signaling. bioRxiv 2022.08.15.504046. 
doi: 10.1101/ 2022.08.15.504046. Aug 15, 2022. 

Also

keywords 'behav' in FonT

keyword 'pnei' in FonT

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

Keywords: behav, brain, pnei, opioid signaling