Ismagul R.
Kostanai State University named after A. Baitursynov, Kazakhstan
Àlmost multiperiodic solution of
evolyutsion equations
Let’s introduce some notations and definitions:
-the class of n-dimensional
-functions,
-satisfying the ñonditions.
and almost multiperiodic in
ñ
- vector- almost period
, where
when
; countable-dimensional vector
, where
; Wm è Vm - functionals that assign vectors Wm
=
( φ1, …, φò, 0,…) è Vm
=
( 0,…,0, φm+1,φò+2, …) to the vector φ = (φ1, ..., φt, ...).
Let’s consider a system of
integrodifferential equations of the form
, (1) where x, Q, R are n-vectors-columns; P (t, φ) is a matrix of dimension n × n, φ = (φ1, ..., φt, ...) is a countable vector, and
,
>0 are small parameters.
Let’s
consider that the conditions
[1,c.168] è
(
) are met if:
1)
vector-function
is bounded and contiguous with all
variables, and has limited contiguous derivatives of first
order in
,
; diagonally - almost in period
, belongs to
-class evenly relatively to
;
2) continuous function
provides
improper integral
, where
is permanent.
Let’s contemplate the differential operator:
.
To
reduce the record we’ll take
. It should be
noted that the coefficients of Lipshitce enhanced condition for vector-function
are
.
Let’s contemplate the linearized equation:
. (2)
Let
be the characteristic function of the functional
, which satisfies the integral equation
.
.
For
characteristic function
there are rates
analogous to relations of the
form I(a-b) è 10-90.
Let’s consider the functional Ò, representing each
vector-function ![]()
![]()
in vector-function


, where

which is known from [1].
We will study

Considering that
, we can write
.
From rates III(a-d) we can conclude that there is such a number
, for which with
all
there are the following relations:
1)
,
2)
,
3)
,
4)
.
Thus, we come to the statement of theorem 1.
Theorem 1. If the conditions
,
are met for the equation (1), than for all
the meanings
,
equation (1) has a single almost
multiperiodic solution from the class
, converging in a
zero vector with
.
REFERENCES:
1. Umbetzhanov D.U. Almost periodic
solutions of evolution equations. Alma-Ata, Nauka, 1990, 188 p.