Random Attractor of the Stochastic Strongly Damped for the Higher-Order Nonlinear Kirchhoff-Type Equation ()
2010 Mathematics Classification: 35K10, 35K25, 35K35
1. Introduction
In this paper, we consider the following stochastic strongly damped higher- order nonlinear Kirchhoff-type equation with white noise:
(1.1)
with the Dirichlet boundary condition
(1.2)
and the initial value conditions
(1.3)
where
is a bounded domain of
, with a smooth boundary
,
is the Laplacian with respect to the variable
,
is a real function of
and
,
is the damping coefficient, f is a given external force, v is the outer norm vector,
is a nonlinear forcing, their respectively satis- fies the following conditions:
1) 
2) 
3) 
4) 
where
are positive constants.
As well as we known, the study of stochastic dynamical is more and more widely the attention of scholars, and the study of random attractor has become an important goal. In a sense, the random attractor is popularized for classic determine dynamical system of the global attractor. Global attractor of Kirchhoff- type equations have been investigated by many authors, see, e.g., [1] [2] [3] [4] , however, the existence random attractor has also been studied by many authors, in [5] , Zhaojuan Wang, Shengfan Zhou and Anhui Gu, they study the asymp- totic dynamics for a stochastic damped wave equation with multiplicative noise defined on unbounded domains, and investigate the existence of a random attractor, they overcome the difficulty of lacking the compactness of Sobolev embedding in unbounded domains by the energy equation. In [6] , Guigui Xu, Libo Wang and Guoguang Lin study the long time behavior of solution to the stochastic strongly damped wave equation with white noise, in this paper, they use the method introduced in [7] , so that they needn’t divide the equation into two parts. In [8] , Zhaojuan Wang, Shengfan Zhou and Anhui Gu study the asymptotic dynamics of the stochastic strongly damped wave equation with homogeneous Neuman boundary condition, and prove the existence of a ran- dom attractor. The other long time behavior of solution of evolution equations, we can see [9] - [19] .
In this work, we deal with random term by using Ornstein-Uhlenbeck process, the key is to handle the nonlinear terms and strongly damped
, and
is also difficult to be conducted. So far as we know, there were no result on random attractor for the stochastic higher-order Kirchhoff-type equ- ation with nonlinear strongly dissipation and white noise. It is therefore im- portant to investigate the existence of random attractor on (1.1)-(1.3).
This paper is organized as follows: In Section 2, we recall many basic concepts related to a random attractor for genneral random dynamical system. In Section 3, we introduce O-U process and deal with random term. In Section 4, we prove the existence of random attractor of the random dynamical system.
2. Preliminaries
In this section, we collect some basic knowledge about general random dy- namical system ( [9] [10] [11] ).
Let
be a separable Hilbert space with Borel s-algebra
. Let
be the metric dynamical system on the probability space
.
Definition 2.1. (see [9] [10] ). A continuous random dynamical system on X over
is a
-measurable mapping
. Such that the following properties hold (1)
1)
is the identity on X;
2)
for all
;
3)
is continuous for all
.
Definition 2.2. (see [10] )
1) A set-valued mapping
, is said to be a random set if the mapping
is measurable for any
. If
is also closed (compact) for each
,
is called a random closed (com- pact) set. A random set
is said to be bounded if there exist
and a random variable
such that
for all
.
2) A random set
is called tempered provided for
,
for all
,
where
.
Let Y be the set of all random tempered sets in X.
3) A random set
is said to be a random absorbing set if for any tempered random set
, and
, there exists
such that
for all
.
4) A random set
is said to be a random attracting set if for any tempered random set
, and
, we have
,
where
is the Hausdorff semi-distance given by
for any
.
5)
is said to be asymptotically compact in X if for
has a convergent subsequence in X whenever
, and
with
.
6) A random compact set
is said to be a random attractor if it is a random attracting set and
for
and all
.
Theorem 2.1. ( [10] ) Let
be a continuous random dynamical system with state space X over
. If there is a closed random absorbing set
of
and
is asymptotically compact in X, then
is a random attractor of
, where
![]()
Moreover,
is the unique random attractor of
.
3. O-U Process and Stochastic Dynamical System
Let
,
,
,
![]()
Let
, and define a weighted inner product and norm in E
,
,
, ![]()
3.1. O-U Process
O-U process is given by Wiener process on the metric system
, we can see ( [11] [12] [13] ).
Let
, where
, for
,
meet Itô
equation:
. And there is a probability measure P,
-in- variant set
; so that stochastic process
meet the following properties:
1) For
, mapping
for continuous mapping;
2) Random variable
is called tempered;
3) Exist temper set
, such that
;
4)
;
5)
.
3.2. Stochastic Dynamical System
For convenience, we rewrite the Question (1.1)-(1.3):
(3.2.1)
Let
, and
(
defined in [20] ), then (3.2.1) has the following simple matrix form
(3.2.2)
where
![]()
![]()
Let
, then (3.2.1) can be rewritten as the equivalent system:
(3.2.3)
where
![]()
![]()
In [14] [15] they have proven that the operator L of (3.2.3) is the infinitesimal generation operator of
semigroup
in Hilbert space E,
is continuous in t and globally Lipschitz continuous in
for each
. By the classical theory concerning the existence and uniqueness of the solutions [14] [16] [17] , so we have the following theorem.
Theorem 3.2.1. Consider (3.2.3). For each
and initial value
, there exists a unique function
such that satisfies the integral equation
![]()
and
![]()
For
, let the solution mapping of ![]()
![]()
generates a random dynamical system.
Define two isomorphic mapping:
![]()
![]()
And inverse isomorphic mapping:
![]()
![]()
Then the mapping
generates a random dynamical system associated with (1.1)-(1.3); and mapping
generates a random dynamical system associated with (3.2.2).
Notice that all of the above random dynamical system
,
are equivalent. Hence we only need to consider the random dynamical system
.
4. The Existence of Random Attractor
First, we prove the random dynamical system
exists a bounded random absorb set, hence we let
be all temper subsets in E.
Lemma 4.1. (Lemma 3.1 of [20] ) Let
, for any
, we have
(4.1)
where
are determined in [20] ,
,
is first eigenvalues of (1.1).
Lemma 4.2. Let
is a solve of (3.2.2), then there is a bounded random com- pact set
, such that for arbitrarily random set
, existence a random variable
, so that
(4.2)
Proof. Let
is a solve of (3.2.3), applying the inner product of the equation (3.2.3) with
, we discover that
(4.3)
where
![]()
(4.4)
(4.5)
(4.6)
(4.7)
(4.8)
(4.9)
(4.10)
According to (4.1) and (4.4)-(4.10), we have
(4.11)
where
![]()
![]()
![]()
According to Gronwall inequation,
, we have
(4.12)
Because
is tempered, and
is continuous about t, according to [21] , we can get a temper random variables
, such that
, we have
(4.13)
Substituting
by
in (4.12), we know
(4.14)
where
(4.15)
Because
is tempered, and
is also tempered, hence we let
(4.16)
then
is also tempered,
is called a random absorb set, and because of
![]()
so let
then
is a random absorb set of
, and
.
Next, we will prove the random dynamical system
has a compact absorb set
Lemma 4.3. For
, let
be a solve of (3.2.2), initial value
, we decompose
, where
satisfy
(4.17)
(4.18)
Then
(4.19)
and exist a temper random radius
, such that
, satisfy
(4.20)
Proof. Let
be a solve of (3.2.3), according to (4.17) and (4.18), we know
meet separately
(4.21)
(4.22)
Taking inner product (4.21) with
, we have
![]()
according to Lemma 4.1 and Gronwall inequality, we have
(4.23)
substituting
by
, and
is tempered, then
![]()
So, (4.19) is hold. Taking inner product (4.22) with
, we have
(4.24)
according to Lemma 4.1, Lemma 4.2, (4.24) and Young inequality, we have
![]()
where
are given by Lemma 4.2, and
![]()
Due to Gronwall inequality, and substituting
by
, we have
![]()
According to (4.14) and (4.16), then
![]()
Let
![]()
Then
is tempered, and because
![]()
hence, we set
then, for
, we have
and
is tempered.
Lemma 4.4. (3.2.2) the identified stochastic dynamical system
, while
exist a compact attracting set
.
Proof. Let
be a closed ball, radius
in space
, because
, so
is a compact
set in E, for arbitrarily temper random set
, for
, ac- cording to Lemma 4.3,
, so for
, we have
![]()
+
Theorem 4.1. The random dynamical system
has a unique random attractor
in E, where
![]()
in which
is a tempered random compact attracting for
.