On arithmetic detection of grey pulses with application to Hawking radiation

"Micron-sized black holes do not necessarily have a constant horizon temperature distribution. The black hole remote-sensing problem means to find out the "surface" temperature distribution of a small black hole from the spectral measurement of its (Hawking) grey pulse. This problem has been previously considered by Rosu, who used Chen's modified Möbius transform inverse transform. Here, we hint on a Ramanujan generalization of Chen's modified Möbius transform inverse transform that may be considered as a special wavelet processing of the remote-sensed grey signal coming from a black hole or any other distant grey source.

Unveiling uncertain forces in second-order driven oscillators via internal model: a discrete-time feedback

"Unveil uncertain forces acting into (or onto) systems is a very interesting and old problem. Indeed, a lot effort has been devoted to develop procedures which results in the understanding of the uncertain forces and its effects. This contribution deals with recovering of the dynamics of the uncertain forces from measurements (time series). The main idea is to construct an internal model of the nonlinear system and design a discretetime feedback in such way that the model/system differences be stabilized at origin. In principle, if the internal model tracks the trajectory of the nonlinear system, then the uncertain force is recovered by the stabilizing command.

A note on optimization of chaos suppression via robust asymptotic feedback: accounting control cost

"This paper deals with the chaos suppression for oscillators in canonical form. The underlying idea is to optimize the robust chaos supression by accounting the control cost. The robust chaos supression is attained by the robust asymptotic feedback while the optimization is solved via Riccatti ecuations. A finite horizon is arbitrarily settled and the suppression is achieved at this time by means of optimal control problem. This scheme allows to take into account the energy that is wasted by the controller and the closed-loop performance of states. Some experimental results show the features of the approach when a High-Gain observer is added in order to have available the complete state vector.

Cálculo numérico de matrices de Lyapunov de sistemas integrales con retardos

"En este artículo se propone un algoritmo numérico para la construcción de matrices de Lyapunov de sistemas integrales con un retardo.