Oscillatory instabilities in Hamiltonian anharmonic lattices are known to appear through Hamiltonian Hopf bifurcations of certain time-periodic solutions of multibreather type. Here, we analyze the basic mechanisms for this scenario by considering the simplest possible model system of this kind where they appear: the three-site discrete nonlinear Schrödinger model with periodic boundary conditi...

A Nonlinear Generalized Minimum Variance control law is derived for systems represented by an input-output state dependent nonlinear subsystem that may be open-loop unstable. The solution is obtained using a model for the multivariable discrete-time process that includes a state-dependent (nonlinear and possibly unstable) model that links the output and any unstructured nonlinear input subsyste...

We construct unstable system D8 + D8 as a kink solution on world-volume of non-BPS D9-brane in IIA theory. Further we will make other checks confirming validity of our approach.

This paper is concerned with the global asymptotic behavior of positive solution for a system of two nonlinear rational difference equations. Moreover, some numerical examples are given to illustrate results obtained. Keywords—Difference equations, stability, unstable, global asymptotic behavior.

In this paper, we obtain some sufficient conditions under which the zero solution of a certain third order non-linear ordinary vector differential equation is unstable. Our results include and improve some well-known results exist in the literature.

A signiicant collection of two-point boundary value problems is shown to give rise to linear systems of algebraic equations on which Gaussian elimination with row partial pivoting is unstable when standard solution techniques are used.

Economists frequently connne themselves to the qualitative analysis of continuous optimization problems or they restrict their quantitative analysis to inaccurate methods like lineariza-tion around the steady state. The fact that the solution is characterized by an inherently unstable adjustment path arriving at a boundary value in innnite time, however, does not necessarily imply a complicated...

We consider the mass-critical focusing nonlinear Schrödinger equation in the presence of an external potential, when the nonlinearity is inhomogeneous. We show that if the inhomogeneous factor in front of the nonlinearity is sufficiently flat at a critical point, then there exists a solution which blows up in finite time with the maximal (unstable) rate at this point. In the case where the crit...

In this paper, we consider a MIMO networked control system with an energy harvesting sensor, where an unstable MIMO dynamic system is connected to a controller via a MIMO fading channel. We focus on the energy harvesting and MIMO precoding design at the sensor so as to stabilize the unstable MIMO dynamic plant subject to the energy availability constraint at the sensor. Using the Lyapunov optim...