Mironenko reflecting function explained

In applied mathematics, the reflecting function

F(t,x)

of a differential system
x=X(t,x)
connects the past state

x(-t)

of the system with the future state

x(t)

of the system by the formula

x(-t)=F(t,x(t)).

The concept of the reflecting function was introduced by Uladzimir Ivanavich Mironenka.

Definition

x=X(t,x)
with the general solution

\varphi(t;t0,x)

in Cauchy form, the Reflecting Function of the system is defined by the formula

F(t,x)=\varphi(-t;t,x).

Application

If a vector-function

X(t,x)

is

2\omega

-periodic with respect to

t

, then

F(-\omega,x)

is the in-period

[-\omega;\omega]

transformation (Poincaré map) of the differential system
x=X(t,x).
Therefore the knowledge of the Reflecting Function give us the opportunity to find out the initial dates

(\omega,x0)

of periodic solutions of the differential system
x=X(t,x)
and investigate the stability of those solutions.

For the Reflecting Function

F(t,x)

of the system
x=X(t,x)
the basic relation

Ft+FxX+X(-t,F)=0,    F(0,x)=x.

is holding.

Therefore we have an opportunity sometimes to find Poincaré map of the non-integrable in quadrature systems even in elementary functions.

Literature

External links