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Related papers: On the Keldysh Problem of Flutter Suppression

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We present recent finite element numerical results on a model convection-diffusion problem in the singular perturbed case when the convection term dominates the problem. We compare the standard Galerkin discretization using the linear…

Numerical Analysis · Mathematics 2023-02-16 Constantin Bacuta , Daniel Hayes , Tyler O'Grady

It is shown how to construct Keldysh diagram technique for pseudo - particle approach to the Hubbard model. We propose self consistent equations for pseudo particle and electron Green functions in Keldysh diagram technique. Nonlocal effects…

Strongly Correlated Electrons · Physics 2014-08-27 P. I. Arseyev , N. S. Maslova

We suggested a one-fluid model of a turbulent dilute suspension which accounts for the ``two-way'' fluid-particle interactions by $k$-dependent effective density of suspension and additional damping term in the Navier-Stokes equation. We…

Chaotic Dynamics · Physics 2007-05-23 Victor S. L'vov , Anna Pomyalov

Hyperexponential stability is investigated for dynamical systems with the use of both, explicit and implicit, Lyapunov function methods. A nonlinear hyperexponential control is designed for stabilizing linear systems. The tuning procedure…

Systems and Control · Electrical Eng. & Systems 2022-07-19 Konstantin Zimenko , Denis Efimov , Andrey Polyakov

We develop a contraction-based framework to establish the existence and exponential stability of periodic solutions in planar nonsmooth dynamical systems governed by Filippov differential inclusions. The method integrates a time- and…

Dynamical Systems · Mathematics 2025-07-10 Pascal Stiefenhofer

We propose a new stabilised finite element method for the classical Kolmogorov equation. The latter serves as a basic model problem for large classes of kinetic-type equations and, crucially, is characterised by degenerate diffusion. The…

Numerical Analysis · Mathematics 2024-12-31 Zhaonan Dong , Emmanuil H. Georgoulis , Philip J. Herbert

The method of Lyapunov functions is one of the most effective ones for the investigation of stability of dynamical systems, in particular, of stochastic differential systems. The main purpose of the paper is the analysis of the stability of…

Analysis of PDEs · Mathematics 2015-03-13 Tomas Caraballo , Mohamed Ali Hammami , Lasaad Mchiri

In this paper we propose a nonconforming finite element method for the solution of the ill-posed elliptic Cauchy problem. We prove error estimates using continuous dependence estimates in the $L^2$-norm. The effect of perturbations in data…

Numerical Analysis · Mathematics 2014-06-18 Erik Burman

The paper deals with analysis and design of sliding mode control systems modeled by finite-dimensional integro-differential equations. Filippov method and equivalent control approach are extended to a class of nonlinear discontinuous…

Optimization and Control · Mathematics 2026-03-24 Andrey Polyakov

The immersed boundary method is a mathematical framework for modeling fluid-structure interaction. This formulation describes the momentum, viscosity, and incompressibility of the fluid-structure system in Eulerian form, and it uses…

Numerical Analysis · Mathematics 2020-02-26 Ben Vadala-Roth , Shashank Acharya , Neelesh A Patankar , Simone Rossi , Boyce E Griffith

We consider the mathematical analysis and numerical approximation of a system of nonlinear partial differential equations that arises in models that have relevance to steady isochoric flows of colloidal suspensions. The symmetric velocity…

Numerical Analysis · Mathematics 2021-08-09 Andrea Bonito , Vivette Girault , Diane Guignard , Kumbakonam R. Rajagopal , Endre Süli

We investigate an example of noise-induced stabilization in the plane that was also considered in (Gawedzki, Herzog, Wehr 2010) and (Birrell, Herzog, Wehr 2011). We show that despite the deterministic system not being globally stable, the…

Probability · Mathematics 2012-10-02 Avanti Athreya , Tiffany Kolba , Jonathan C. Mattingly

We review various methods to investigate the statics and the dynamics of collective composition fluctuations in dense polymer mixtures within fluctuating-field approaches. The central idea of fluctuating-field theories is to rewrite the…

Soft Condensed Matter · Physics 2007-05-23 Marcus Mueller , Friederike Schmid

We consider 2D Yukawa theory in the strong scalar wave background. We use operator and functional formalisms. In the latter the Schwinger--Keldysh diagrammatic technique is used to calculate retarded, advanced and Keldysh propagators. We…

High Energy Physics - Theory · Physics 2021-09-07 E. T. Akhmedov , O. Diatlyk , A. G. Semenov

For discrete-time systems, governed by Kraus maps, the work of D. Petz has characterized the set of universal contraction metrics. In the present paper, we use this characterization to derive a set of quadratic Lyapunov functions for…

Optimization and Control · Mathematics 2013-02-28 Pierre Rouchon , Alain Sarlette

We extend the Lyapunov function technique, a fundamental tool for investigating asymptotic stability and existence of attractors for ordinary differential equations, by introducing the notion of a {\it strong Lyapunov function} for an…

Dynamical Systems · Mathematics 2025-12-23 Luu Hoang Duc , Jürgen Jost

The Reynolds equation, combined with the Elrod algorithm for including the effect of cavitation, resembles a nonlinear convection-diffusion-reaction (CDR) equation. Its solution by finite elements is prone to oscillations in…

Numerical Analysis · Mathematics 2023-10-12 Hauke Gravenkamp , Simon Pfeil , Ramon Codina

In this article, we introduce Lyapunov-type results to investigate the stability of the trivial solution of a Stieltjes dynamical system. We utilize prolongation results to establish the global existence of the maximal solution. Using…

Classical Analysis and ODEs · Mathematics 2024-09-06 Lamiae Maia , Noha El Khattabi , Marlène Frigon

Two different controlling methods are proposed to stabilize unstable continuous-sliding states of a dry-friction oscillator. Both methods are based on a delayed-feedback mechanism well-known for stabilizing periodic orbits in deterministic…

chao-dyn · Physics 2009-10-30 Franz-Josef Elmer

Inspired by the widespread concept of Lyapunov-Krasovskii functionals of complete type, this article proposes an alternative class of functionals, termed Lyapunov-Krasovskii functionals of robust type. Their construction aims at improving…

Systems and Control · Electrical Eng. & Systems 2025-11-12 Tessina H. Scholl