English
Related papers

Related papers: A geometrical view of scalar modulation instabilit…

200 papers

We introduce a complete analytical and numerical study of the modulational instability process in a system governed by a canonical nonlinear Schr\"odinger equation involving local, arbitrary nonlinear responses to the applied field. In…

Pattern Formation and Solitons · Physics 2015-01-08 David Novoa , Daniele Tommasini , José A. Nóvoa-López

The gauge-independent invariant approach to investigation of the linear scalar perturbations of inflaton and gravitational fields is developed in self-consistent way. This approach allows to compare various gauges used by other researchers…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Roman S. Pasechnik , Gregory M. Vereshkov

The calculation of the transfer matrix for a large non-periodic multilayered system may become unstable in the presence of absorption. We discuss the origin of this instability and we explore two methods to overcome it: the use of a total…

The turbulent dynamics of nearby and extragalactic gas structures can be studied with the column density power spectrum, which is often described by a broken power-law.In an extragalactic context, the breaks in the power spectra have been…

Astrophysics of Galaxies · Physics 2021-06-09 Bastian Körtgen , Nickolas Pingel , Nicholas Killerby-Smith

The authors propose a new modeling approach based on the impedance field method (IFM) to analyze the general geometric variations in device simulations. Compared with the direct modeling of multiple variational devices, the proposed…

Mesoscale and Nanoscale Physics · Physics 2016-04-27 Bo Fu , Seonghoon Jin , Woosung Choi , Keun-Ho Lee , Young-Kwan Park

Modulational instability in a photorefractive medium is studied in the presence of two wave mixing. We then propose and derive a model for forward four wave mixing in the photorefractive medium and investigate the modulational instability…

Pattern Formation and Solitons · Physics 2009-11-13 C. P. Jisha , V. C. Kuriakose , K. Porsezian , B. Kalithasan

The modulational instability of broadband optical pulses in a four-state atomic system is investigated. In particular, starting from a recently derived generalized nonlinear Schr\"odinger equation, a wave-kinetic equation is derived. A…

Pattern Formation and Solitons · Physics 2007-05-23 M. Marklund , P. K. Shukla , R. Bingham , J. T. Mendonca

This work explores a novel approach to mitigating turbulence in fusion plasmas through spatially modulated plasma profiles. By imposing a harmonic modulation on plasma parameters, we introduce conditions that alter the propagation…

Plasma Physics · Physics 2024-12-10 Ilya Shesterikov

We present the first experimental observation of modulation instability of partially spatially incoherent light beams in non-instantaneous nonlinear media. We show that even in such a nonlinear partially coherent system (of…

We consider the problem of designing a feedback controller which robustly regulates an LTI system to an optimal operating point in the presence of unmeasured disturbances. A general design framework based on so-called optimality models was…

Optimization and Control · Mathematics 2022-08-18 John W. Simpson-Porco

Understanding the phase behavior of mixtures with many components is important in many contexts, including as a key step toward a physics-based description of intracellular compartmentalization. Here, we study the instabilities of a mixture…

Statistical Mechanics · Physics 2023-08-16 Filipe C Thewes , Matthias Krüger , Peter Sollich

We investigate the phenomenon of parametric instability in discrete models of spatiotemporally modulated materials. These materials are celebrated in part because they exhibit nonreciprocal transmission characteristics. However, parametric…

Materials Science · Physics 2025-10-20 Jiuda Wu , Behrooz Yousefzadeh

We use a perturbative approach to evaluate transition amplitudes corresponding to quantum friction, for a scalar model describing an atom which moves at a constant velocity, close to a material plane. In particular, we present results on…

High Energy Physics - Theory · Physics 2023-08-29 Aitor Fernández , C. D. Fosco

We analyze the modulation instability induced by periodic variations of group velocity dispersion and nonlinearity in optical fibers, which may be interpreted as an analogue of the well-known parametric resonance in mechanics. We derive…

Optics · Physics 2015-06-11 Andrea Armaroli , Fabio Biancalana

The energy transition is causing many stability-related challenges for power systems. Transient stability refers to the ability of a power grid's bus angles to retain synchronism after the occurrence of a major fault. In this paper a…

Optimization and Control · Mathematics 2021-01-12 Tim Aschenbruck , Willem Esterhuizen , Stefan Streif

The rapid rise in inverter-based renewable resources has heightened concerns over subsynchronous resonance and oscillations, thereby challenging grid stability. This paper reviews approaches to identify and mitigate these issues, focusing…

Systems and Control · Electrical Eng. & Systems 2025-01-16 Shuvangkar Chandra Das , Lokesh Saravana , Le Minh Vu , Manh Bui , Tuyen Vu , Jianhua Zhang , Thomas Ortmeyer

We show that scaling arguments are very useful to analyze the dynamics of periodically modulated noisy systems. Information about the behavior of the relevant quantities, such as the signal-to-noise ratio, upon variations of the noise…

Statistical Mechanics · Physics 2016-08-15 J. M. G. Vilar , J. M. Rubí

We investigate theoretically the fundamental phenomenon of the spontaneous, noise-induced modulational instability (MI) of a plane wave. The long-term statistical properties of the noise-induced MI have been previously observed in…

Exactly Solvable and Integrable Systems · Physics 2019-12-11 Andrey Gelash , Dmitry Agafontsev , Vladimir Zakharov , Gennady El , Stephane Randoux , Pierre Suret

Proportional-Integral-Differential (PID) control is widely used in industrial control systems. However, up to now there are at least two open problems related with PID control. One is to have a comprehensive understanding of its robustness…

Systems and Control · Electrical Eng. & Systems 2025-04-22 Bo Zhu , Wei Yu , Hugh H. T. Liu

Galactic dynamo models have generally relied on input parameters that are very challenging to constrain. We address this problem by developing a model that uses observable quantities as input: the galaxy rotation curve, the surface…

Astrophysics of Galaxies · Physics 2024-04-04 Luke Chamandy , Rion Glenn Nazareth , Gayathri Santhosh