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We present an analytic theory unraveling the microscopic mechanism of instabilities within interacting $D$-dimensional Fermi liquid. Our model consists of a $D$-dimensional electron gas subject to an instantaneous electron-electron…

Strongly Correlated Electrons · Physics 2025-01-03 Dmitry Miserev , Herbert Schoeller , Jelena Klinovaja , Daniel Loss

Physics Informed Neural Networks (PINNs) often exhibit failure modes in which the PDE residual loss converges while the solution error stays large, a phenomenon traditionally blamed on local optima separated from the true solution by steep…

Machine Learning · Computer Science 2025-12-01 Chenhui Xu , Dancheng Liu , Amir Nassereldine , Jinjun Xiong

Functionally graded materials (FGMs) are two-phase composites with continuously changing microstructure adapted to performance requirements. Traditionally, the overall behavior of FGMs has been determined using local averaging techniques or…

Materials Science · Physics 2011-08-31 Zahra Sharif-Khodaei , Jan Zeman

In this paper, we show that the quasi-one-dimensional flow of an ideal inviscid fluid in a corrugated pipe is parametrically unstable in certain frequency bands. First-order perturbation theory is used to analyze the stability of the flow,…

Fluid Dynamics · Physics 2021-02-09 Nikita V. Bykov

Instabilities are common phenomena frequently observed in nature, sometimes leading to unexpected catastrophes and disasters in seemingly normal conditions. The simplest form of instability in a distributed system is its response to a…

Pattern Formation and Solitons · Physics 2016-02-05 O. Kimmoun , H. C. Hsu , H. Branger , M. S. Li , Y. Y. Chen , C. Kharif , M. Onorato , E. J. R. Kelleher , B. Kibler , N. Akhmediev , A. Chabchoub

We investigate the nontrivial characteristics of modulational instability (MI) in a system of Bragg gratings with saturable nonlinearity. We also introduce an equal amount of gain and loss into the existing system which gives rise to an…

Pattern Formation and Solitons · Physics 2023-05-24 K. Tamilselvan , A. Govindarajan , I. Inbavalli , T. Alagesan , M. Lakshmanan

The proportional-integral-derivative (PID) controller and its variants are widely used in control engineering, but they often rely on linearization around equilibrium points and empirical parameter tuning, making them ineffective for…

Systems and Control · Electrical Eng. & Systems 2026-01-13 Zimao Sheng

In order to perform physically faithful particle-in-cell (PIC) simulations, the Gauss's law stands as a critical requirement, since its violation often leads to catastrophic errors in long-term plasma simulations. This work proposes a novel…

Plasma Physics · Physics 2025-06-04 Zhonghua Qiao , Zhenli Xu , Qian Yin , Shenggao Zhou

The pseudo-spectral analytical time-domain (PSATD) particle-in-cell (PIC) algorithm solves the vacuum Maxwell's equations exactly, has no Courant time-step limit (as conventionally defined), and offers substantial flexibility in plasma and…

Computational Physics · Physics 2015-06-16 Brendan B. Godfrey , Jean-Luc Vay , Irving Haber

The effects of noise in particle-in-cell (PIC) and Vlasov simulations of the Buneman instability in unmagnetized plasmas are studied. It is found that, in the regime of low drift velocity, the linear stage of the instability in PIC…

We explore the possibilities of applying structure-preserving numerical methods to a plasma hybrid model with kinetic ions and mass-less fluid electrons satisfying the quasi-neutrality relation. The numerical schemes are derived by finite…

Numerical Analysis · Mathematics 2023-04-05 Yingzhe Li , Martin Campos Pinto , Florian Holderied , Stefan Possanner , Eric Sonnendrücker

Particle-in-cell (PIC) simulations are essential for studying kinetic plasma processes, but they often suffer from statistical noise, especially in plasmas with fast flows. We have also found that the typical central difference scheme used…

Computational Physics · Physics 2025-06-16 Yuxi Chen , Hongyang Zhou , Gabor Toth

We study the spatio-temporal instability generated by a universal unstable attractor in normal dispersion graded-index multimode fiber (GRIN MMF) for femtosecond pulses. Our results present the generation of geometric parametric instability…

Optics · Physics 2017-11-06 Uğur Teğin , Bülend Ortaç

Across many plasma applications, the underlying phenomena and interactions among the involved processes are known to exhibit three-dimensional characteristics. Furthermore, the global properties and evolution of plasma systems are often…

Plasma Physics · Physics 2024-11-11 Maryam Reza , Farbod Faraji , Aaron Knoll

This study investigates the streaming instability triggered by ion motion in a plasma system that is finite in length, collisionless, and inhomogeneous. Employing numerical simulations using Particle-In-Cell (PIC) techniques and kinetic…

Plasma Physics · Physics 2024-05-07 R. Mishra , R. Moulick , S. Adhikari , S. Marholm , A. J. Eklund , W. J. Miloch

Explicit structure-preserving geometric Particle-in-Cell (PIC) algorithm in curvilinear orthogonal coordinate systems is developed. The work reported represents a further development of the structure-preserving geometric PIC algorithm…

Plasma Physics · Physics 2021-05-26 Jianyuan Xiao , Hong Qin

The rapid development of AI highlights the pressing need for sustainable energy, a critical global challenge for decades. Nuclear fusion, generally seen as an ultimate solution, has been the focus of intensive research for nearly a century,…

The problem of existence and stability of equilibria of DC microgirds with constant power loads methods is addressed in this paper. Constant power loads (CPLs) often cause instability due to its negative impedance characteristics. What is…

Systems and Control · Computer Science 2018-07-30 Zhangjie Liu , Mei Su , Yao Sun , Wenbin Yuan , Hua Han

Since the classical proportional-integral-derivative (PID) controller has continued to be the most widely used feedback methods in engineering systems by far, it is crucial to investigate the working mechanism of PID in dealing with…

Optimization and Control · Mathematics 2025-12-03 Baoyou Qu , Cheng Zhao

In the presence of strong electronic interactions, a partially filled Chern band may stabilize a fractional Chern insulator (FCI) state, the zero-field analog of the fractional quantum Hall phase. While FCIs have long been hypothesized,…

Strongly Correlated Electrons · Physics 2024-10-15 Gal Shavit , Yuval Oreg