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Influenced by the fact that vorticity represents rotation for rigid body, people believe it also works for fluid flow. However, the theoretical predictions by vorticity do not match experiment results, which drove scientists to look for…

Fluid Dynamics · Physics 2020-08-18 Yifei Yu1 , Pushpa Shrestha , Oscar Alvarez , Charles Nottage , Chaoqun Liu

Vortex $\gamma$ photons carrying orbital angular momenta (OAM) hold great potential for various applications. However, their generation remains a great challenge. Here, we successfully generate sub-MeV vortex $\gamma$ photons via…

Vortices are topological objects representing the circular motion of a fluid. With their additional degree of freedom, the 'vorticity', they have been widely investigated in many physical systems and different materials for fundamental…

Vortex flows have been found in the photosphere, chromosphere and low corona in observations and simulations. It has been suggested that vortices play an important role for channeling energy and plasma into the corona, but the impact of…

Solar and Stellar Astrophysics · Physics 2023-07-05 C. Breu , H. Peter , R. Cameron , S. K. Solanki

Superfluid turbulent wakes behind a square prism are studied theoretically and numerically by proper orthogonal decomposition (POD). POD is a data science approach that can efficiently extract the principal vibration modes of a physical…

Quantum Gases · Physics 2025-06-16 Sota Yoneda , Hiromitsu Takeuchi

The spatio-temporal dynamics of the solar photosphere is studied by performing a Proper Orthogonal Decomposition (POD) of line of sight velocity fields computed from high resolution data coming from the MDI/SOHO instrument. Using this…

Astrophysics · Physics 2009-11-13 A. Vecchio , V. Carbone , F. Lepreti , L. Primavera , L. Sorriso-Valvo , P. Veltri , G. Alfonsi , Th. Straus

Proton radiography is a central diagnostic technique for measuring electromagnetic (EM) fields in high-energy-density, laser-produced plasmas. In this technique, protons traverse the plasma where they accumulate small EM deflections which…

Previous studies have discovered a population of small granules with diameters less than 800 km showing differing physical properties. High resolution simulations and observations of the solar granulation, in combination with automated…

Solar and Stellar Astrophysics · Physics 2017-02-15 Birgit Lemmerer , Arnold Hanslmeier , Herbert Muthsam , Isabell Piantschitsch

In the recent papers, we introduced a method utilised to measure the flow field. The method is based on the tracking of supergranular structures. We did not precisely know, whether its results represent the flow field in the photosphere or…

Gravity inversion is a commonly applied data analysis technique in the field of geophysics. While machine learning methods have previously been explored for the problem of gravity inversion, these are deterministic approaches returning a…

Modeling studies consistently demonstrate that the most violent winds in tornadic vortices occur in the lowest tens of meters above the surface. These velocities are unobservable by radar platforms due to line of sight consider- ations. In…

Dynamical Systems · Mathematics 2013-02-26 Sean Crowell , Luther White , Louis Wicker

We use numerical simulations and linear stability analysis to study the dynamics of an active liquid crystal film on a substrate in the regime where the passive system would be isotropic. Extensile activity builds up local orientational…

Soft Condensed Matter · Physics 2023-09-26 Fernando Caballero , Zhihong You , M. Cristina Marchetti

State-of-the-art atmospheric turbulence image restoration methods utilize standard image processing tools such as optical flow, lucky region and blind deconvolution to restore the images. While promising results have been reported over the…

Image and Video Processing · Electrical Eng. & Systems 2019-05-21 Nicholas Chimitt , Zhiyuan Mao , Guanzhe Hong , Stanley H. Chan

We propose Flow Mismatching, an unsupervised anomaly detection method that deliberately avoids reconstruction-based paradigms. Instead, we treat flow matching as geometric dynamics and leverage a key insight: anomalies occur at places where…

Computer Vision and Pattern Recognition · Computer Science 2026-05-25 Shengzhe Chen , Mehrdad Moradi , Kamran Paynabar , Hao Yan

Context. Small-scale bright features in the photosphere of the Sun, such as faculae or G-band bright points, appear in connection with small-scale magnetic flux concentrations. Aims. Here we report on a new class of photospheric bright…

Solar and Stellar Astrophysics · Physics 2016-12-14 Flavio Calvo , Oskar Steiner , Bernd Freytag

We investigate the propagation of optical vector vortices of slow light in a coherently prepared four-level tripod atomic system. The vector vortex consists of superposed pulse pairs with opposite circular polarizations and orbital angular…

Vortices are one of the most promising mechanisms to locally concentrate millimeter dust grains and allow the formation of planetesimals through gravitational collapse. The outer disk around the binary system HD 142527 is known for its…

Earth and Planetary Astrophysics · Physics 2021-06-09 Y. Boehler , F. Ménard , C. M. T. Robert , A. Isella , C. Pinte , J. -F. Gonzalez , G. van der Plas , E. Weaver , R. Teague , H. Garg , H. Méheut

Time--distance inversions usually provide tomographic maps of the interesting plasma properties (we will focus on flows) at various depths. These maps however do not correspond directly to the flow field, but rather to the true flow field…

Solar and Stellar Astrophysics · Physics 2017-04-12 M. Svanda , M. Kozon

Oriented object detection is a crucial task in computer vision. Current top-down oriented detection methods usually directly detect entire objects, and not only neglecting the authentic direction of targets, but also do not fully utilise…

Computer Vision and Pattern Recognition · Computer Science 2022-02-15 Beihang Song , Jing Li , Shan Xue , Jun Chang , Jia Wu , Jun Wan , Tianpeng Liu

Separated flows past complex geometries are modelled by discrete vortex techniques. The flows are assumed to be rotational and inviscid, and a new technique is described to determine the streamfunctions for linear shear profiles. The…

chao-dyn · Physics 2007-05-23 P. Franzese , L. Zannetti