ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Unbekannt

Linking the Langevin equation to scaling properties of space plasma turbulence at sub-ion scales (2024)

Benella, Simone ; Stumpo, Mirko ; Alberti, Tommaso ; [weitere]

American Physical Society

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2024-04-30

Beschreibung: Current understanding of the kinetic-scale turbulence in weakly collisional plasmas still remains elusive. We employ a general framework in which the turbulent energy transfer is envisioned as a scale-to-scale Langevin process. Fluctuations in the sub-ion range show a global scale invariance, thus suggesting a homogeneous energy repartition. In this Letter, we interpret such a feature by linking the drift term of the Langevin equation to scaling properties of fluctuations. Theoretical expectations are verified on solar wind observations and numerical simulations, thus giving relevance to the proposed framework for understanding kinetic-scale turbulence in space plasmas.

Beschreibung: Published

Beschreibung: L042014

Beschreibung: OSA3: Climatologia e meteorologia spaziale

Beschreibung: JCR Journal

Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)

Materialart: article

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

ARTIKEL (OA)

S·F·X

PDF

Volltext

2

Unbekannt

Spintronics-compatible approach to solving maximum satisfiability problems with probabilistic computing, invertible logic and parallel tempering (2023)

Grimaldi, Andrea ; Sánchez-Tejerina San José, Luis ; Aadit, Muhammad Navid Anjum ; [weitere]

American Physical Society

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2023-02-22

Beschreibung: 7 Figures, 20 pages

Beschreibung: The search of hardware-compatible strategies for solving NP-hard combinatorial optimization problems (COPs) is an important challenge of today s computing research because of their wide range of applications in real world optimization problems. Here, we introduce an unconventional scalable approach to face maximum satisfiability problems (Max-SAT) which combines probabilistic computing with p-bits, parallel tempering, and the concept of invertible logic gates. We theoretically show the spintronic implementation of this approach based on a coupled set of Landau-Lifshitz-Gilbert equations, showing a potential path for energy efficient and very fast (p-bits exhibiting ns time scale switching) architecture for the solution of COPs. The algorithm is benchmarked with hard Max-SAT instances from the 2016 Max-SAT competition (e.g., HG-4SAT-V150-C1350-1.cnf which can be described with 2851 p-bits), including weighted Max-SAT and Max-Cut problems.

Beschreibung: Published

Beschreibung: 024052

Beschreibung: 3IT. Calcolo scientifico

Beschreibung: JCR Journal

Schlagwort(e): Physics - Mesoscopic Systems and Quantum Hall Effect; Physics - Mesoscopic Systems and Quantum Hall Effect

Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)

Materialart: article

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

ARTIKEL (OA)

S·F·X

PDF

Volltext

3

Unbekannt

Physical mechanisms of the linear stabilization of convection by rotation (2022)

Carpenter, Jeffrey R. ; Liang, Yu ; Timmermans, Mary-Louise ; [weitere]

American Physical Society

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2023-01-04

Beschreibung: Despite the well-known limitations of linear stability theory in describing nonlinear and turbulent flows, it has been found to accurately capture the transitions between certain nonlinear flow behavior. Specifically, the transition in heat flux scaling in rotating convective flows can be well predicted by applying a linear stability analysis to simple profiles of a convective boundary layer. This fact motivates the present study of the linear mechanisms involved in the stability properties of simple convective setups subject to rotation. We look at an idealized two-layer setup and gradually add complexity by including rotation, a bounded domain, and viscosity. The two-layer setup has the advantage of allowing for the use of wave interaction theory, traditionally applied to understand stratified and homogeneous shear flow instabilities, in order to quantify the various physical mechanisms leading to the growth of convective instabilities. We quantitatively show that the physical mechanisms involved in the stabilization of convection by rotation take two different forms acting within the stratified interfacial region, and in the homogeneous mixed layers. The latter of these we associate with the tendency of a rotating flow to develop Taylor columns (TCs). This TC mechanism can lead to both a stabilization or destabilization of the instability and varies depending on the parameters of the problem. A simple criterion is found for classifying the influence of these physical mechanisms.

Materialart: Article , PeerReviewed

Format: text

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

ARTIKEL (OCEANREP)

S·F·X

PDF

Volltext

4

Unbekannt

Pond fractals in a tidal flat (2015)

Cael, B. Barry ; Lambert, Bennett ; Bisson, Kelsey

American Physical Society

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2022-05-25

Beschreibung: © The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Physical Review E Statistical, Nonlinear, and Soft Matter Physics 92 (2015): 052128, doi: 10.1103/PhysRevE.92.052128.

Beschreibung: Studies over the past decade have reported power-law distributions for the areas of terrestrial lakes and Arctic melt ponds, as well as fractal relationships between their areas and coastlines. Here we report similar fractal structure of ponds in a tidal flat, thereby extending the spatial and temporal scales on which such phenomena have been observed in geophysical systems. Images taken during low tide of a tidal flat in Damariscotta, Maine, reveal a well-resolved power-law distribution of pond sizes over three orders of magnitude with a consistent fractal area-perimeter relationship. The data are consistent with the predictions of percolation theory for unscreened perimeters and scale-free cluster size distributions and are robust to alterations of the image processing procedure. The small spatial and temporal scales of these data suggest this easily observable system may serve as a useful model for investigating the evolution of pond geometries, while emphasizing the generality of fractal behavior in geophysical surfaces.

Beschreibung: This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. 2388357, the Gordon and Betty Moore Foundation, and the National Science Foundation, Award No. OCE-1315201.

Repository-Name: Woods Hole Open Access Server

Materialart: Article

Format: application/pdf

Permalink