Department of Plasma Physics and Technology on LinkedIn: Conference Information (2024)

When I started my masters degree three years ago, I didn't imagine that i would have an academic paper published during such difficult times of war here in Israel. How can feelings of sorrow and concern be mixed with a feeling of personal accomplishment? But it's these things we do, these normal things, that remind us who we are and help us overcome.In our work, 'Generating Angular-Varying Time Delays of THz Pulses via Direct Space-to-Time Mapping of Metasurface Structures', which was published on ACS Applied Optical Materials, we experimentally demonstrate the ability to generate double terahertz (THz) pulses and have the nonlinear spatial response profile of our metasurface directly mapped to the far-field THz temporal profile. We use the geometric Pancharatnam-Berry phase to generate symmetric and antisymmetric spatiotemporal profiles, and present the possibility to multiplex orthogonal polarizations in order to have a full range of elliptical THz polarizations. You can read about it here: https://lnkd.in/dn3R2hr8

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Delighted to share our recent publication: "Data-driven Modeling and Parameter Estimation of Nonlinear Systems." This paper introduces a novel data-driven approach for accurately modeling and estimating parameters of nonlinear systems utilizing trust region optimization. Access the full paper here: https://lnkd.in/exQS6tGd

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Online estimation of the inverse of the Hessian for stochastic optimization with application to universal stochastic Newton algorithmsAntoine Godichon-Baggioni (LPSM (UMR_8001)), Wei Lu (LMI), Bruno Portier (LMI)Abstract This paper addresses second-order stochastic optimization for estimating the minimizer of a convex function written as an expectation. A direct recursive estimation technique for the inverse Hessian matrix using a Robbins-Monro procedure is introduced. This approach enables to drastically reduces computational complexity. Above all, it allows to develop universal stochastic Newton methods and investigate the asymptotic efficiency of the proposed approach. This work so expands the application scope of secondorder algorithms in stochastic optimization.#machinelearning

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📃Scientific paper: Embedded graph 3-coloring and flowsAbstract:A graph drawn in a surface is a near-quadrangulation if the sum of thelengths of the faces different from 4-faces is bounded by a fixed constant.Weleverage duality between colorings and flows to design an efficient algorithmfor 3-precoloring-extension in near-quadrangulations of orientable surfaces.Furthermore, we use this duality to strengthen previously known sufficientconditions for 3-colorability of triangle-free graphs drawn in orientablesurfaces.;Comment: 53 pages, 15 figures Discover the rest of the scientific article on es/iode ➡️https://etcse.fr/Ps1

Check out our new paper on the almost-sure convergence of the primal iterates and Lagrange multipliers in a stochastic-gradient-based algorithm for solving nonlinearly constrained optimization problems: https://lnkd.in/e85MX2D7

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🔬Exploring the Depths of Non-Markovian Dynamics in Depolarizing Maps🔬I am pleased to share our recent work. Our recent preprint on arXiv has delved into the complex dynamics of non-Markovian systems, specifically focusing on the depolarizing channel. We have explored the depolarizing channel's non-Markovian behaviour using various techniques to identify and quantify non-Markovianity, including quantum information backflow witness, BLP, RHP, and HCLA measures. In addition, a geometrical visualisation of non-Markovian effects using the variation in the volume of accessible states during dynamical evolution is presented. Also, there has been an emphasis on trajectory-based visualisation of the dynamical map of the depolarizing channel within the parameter space.This work is a significant contribution to our understanding of quantum systems and their dynamics. For more details, check out the full paper on arXiv: https://lnkd.in/gm_Wr856.#QuantumPhysics #NonMarkovianDynamics #DepolarizingMaps

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Hi everyone, Our paper titled "Which shapes can appear in a Curve Shortening Flow Singularity" has been posted on arxiv.org, (https://lnkd.in/esaaZXaN). The project was supervised by Prof. Sigurd Angenent, UW-Madison. The paper studies the possible tangles that can occur in singularities of solutions to plane Curve Shortening Flow. We introduce the so-calledn-loop curves, which generalize Matt Grayson's Figure-Eight curve, and we conjecture a generalization of the Coiculescu-Schwarz asymptotic bow-tie result. In particular, we exhibit solutions in which more complicated tangles with more than one self-intersection disappear into a singular point. Any comments are welcome. #mathematics #Differential #geometry #AnalysisofPDE

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🤓"𝗠𝗮𝘀𝘁𝗲𝗿𝗶𝗻𝗴 𝗯𝗮𝘀𝗶𝗰 𝗧𝗼𝗽𝗼𝗹𝗼𝗴𝘆 : 𝗧𝗵𝗲 𝗙𝗶𝗻𝗮𝗹 𝗨𝗻𝗶𝘁 𝗡𝗼𝘁𝗲𝘀" Hello 👋📁 Here's the last 4th unit notes of toplogy with the topics covered as mention ⬇ . ✏With this post I am concluding topology notes. 📝 I am so happy that I have shared Complex analysis and Topology complete handwriting detailed notes. Thank you so much for supporting so far. 😁1. To Space2. T3 axiom.3. Regular Space.4. Relation between Regular Hausdorff space5. Some results on Hausdorff spare.6. T4 axiom..7. Normal space8. General examples of normal spare. (& Theorem).9. Cauchy sequence10. Convergent sequence.11. Complete metric space.12. Cantor's Intersection theorem.13. Nowhere dense set with example.14. closed sphere.15. Baire's theorem. #thankyou #topology #notes #unit4 #handwrittennotes #mathematics #growth #learntogether #knowledgesharing #knowledgeexchange #msc #bsc #cantor #theorem #proof notes helping for topics in : #NET #JRF

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📃Scientific paper: What are the parities of photon-ring images near a black hole?Abstract:Light that grazes a black-hole event horizon can loop around one or moretimes before escaping again, resulting for distance observers in an infinitesequence of ever fainter and more delayed images near the black hole shadow.Inthe case of the M87 and Sgr A$^*$ back holes, the first of these so-calledphoton-ring images have now been observed.A question then arises: are suchimages minima, maxima, or saddle-points in the sense of Fermat's principle ingravitational lensing?or more briefly, the title question above.In the theoryof lensing by weak gravitational fields, image parities are readily found byconsidering the time-delay surface (also called the Fermat potential or thearrival-time surface).In this work, we extend the notion of the time delaysurface to strong gravitational fields and compute the surface for aSchwarzschild black hole.The time-delay surface is the difference of twowavefronts, one travelling forward from the source and one travelling backwardsfrom the observer.Image parities are read off from the topography of thesurface, exactly as in the weak-field regime, but the surface itself is morecomplicated.Of the images, furthest from the black hole and similar to theweak-field limit, are a minimum and a saddle point.The strong field repeatsthe pattern, corresponding to light taking one or more loops around the backhole.In between, there are steeply-rising walls in the time-delay surface,which can be interpreted as maxima and s...Continued on ES/IODE ➡️ https://etcse.fr/MDwj-------If you find this interesting, feel free to follow, comment and share.We need your help to enhance our visibility, so that our platform continues to serve you.