Volume 2010, Article ID 101959, 19 pagesdoi:10.1155/2010/101959 Research Article A Mixed Problem for Quasilinear Impulsive Hyperbolic Equations with Non Stationary Boundary and Transmiss
Trang 1Volume 2010, Article ID 101959, 19 pages
doi:10.1155/2010/101959
Research Article
A Mixed Problem for Quasilinear Impulsive
Hyperbolic Equations with Non Stationary
Boundary and Transmission Conditions
1 Azerbaijan Technical University, AZ 1073, Baki, Azerbaijan
2 Institute of Mathematics and Mechanics of NAS of Azerbaijan, AZ 1141, Baku, Azerbaijan
Received 10 March 2010; Revised 13 June 2010; Accepted 26 October 2010
Academic Editor: Toka Diagana
under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
The initial-boundary value problem for a class of linear and nonlinear equations in Hilbert space
is considers We prove the existence and uniqueness of solution of this problem The results of this investigation are applied to solvability of initial-boundary value problems for quasilinear impulsive hyperbolic equations with non-stationary transmission and boundary conditions
1 Abstract Model Initial Boundary Value Problem with
Non Stationary Boundary and Transmission Conditions for
the Impulsive Linear Hyperbolic Equations
hyperbolic equations with non stationary boundary conditions In this direction, some results were obtained in2
In this paper, we offer the analogues abstract model of investigation of mixed problem with non stationary boundary and transmission conditions for impulsive linear and semilinear hyperbolic equations
1.1 Statement of the Problem and Main Theorem
Let H i , H i
0, X i
ν , Y μ j ν 1, 2, , s i ; i 1, 2, , m; μ 1, 2, , r j ; j 1, 2, , m be Hilbert
Spaces Consider the following abstract initial-boundary value problem:
Trang 2¨u i t A i tu i t f i t, hyperbolic equations
B iν ¨u i t m
k1
C i kν tu k t g iν t, non stationary boundary and transmission conditions
,
m
k1
,
u i 0 u0
i , ˙u i 0 u1
i , initial conditions,
1.2
where t ∈ 0, T, ¨u i d2u i /dt2, ˙u i du i /dt, A i t are the linear closed operators in H i ; B iνare
the linear operators from H i to X i
ν ; C i kν t are the linear operators from H k to X i
ν ; D kμ j are the
linear operators from H k to Y μ j ; ν 1, , s i , i 1, , m, μ 1, , r j , j 1, , m, k 1, , m.
We will investigate this problem under the following conditions
i Let H i
1, 2, , m.
In the Hilbert space H i, it was defined the system of the inner products·, · H i t, which generate uniform equivalent norms, that is,
c1−1u2
H i ≤ u2
H i t ≤ c1u2
H i , c1> 0,
u2
For each u ∈ H i , the function t → u2
H i t:0, T → Ris continuously differentiable,
i 1, 2, , m.
ν, it was defined the system of the inner products·, · X
νi, which generate uniform equivalent norms, that is,
c−12 v2
X i
ν ≤ v2
X i
ν t ≤ c2v2
X i
ν , c2> 0,
v2
X i
ν t v, v X i
ν t , t ∈ 0, T, ν 1, 2, , s i , i 1, 2, , m. 1.4
For each v ∈ X i
ν , the function t → v2
X i
ν t:0, T → Ris continuously differentiable
ii For each t ∈ 0, T and i 1, 2, , m, A i t is a linear closed operator in H iwhose
domain is H0i ; A i t acts boundedly from H i
0to H i ; A i t is strongly continuously
differentiable
H i
0, H i1/2 is interpolation space between H0i and H i of order 1/2 ν 1, , s i , i
1, , m see 3
ν, are
kν t is strongly continuously differentiable ν 1, , s i , i 1, , m;
k 1, , m.
Trang 3v The linear operators D j
kμ , from H 1/2 k into Y μ j, act boundedly μ 1, , r j , j
1, , m; k 1, , m.
Let us introduce the following designations:
H H1⊕ · · · ⊕ H m ,
H0
u : u u1, , u m , u i ∈ H i
0, i 1, , m;
m
k1
D j kμ u k 0, μ 1, , r j , j 1, , m
,
H 1/2
u : u u1, , u m , u i ∈ H i
1/2 , i 1, , m;
m
k1
D j kμ u k 0, μ 1, , r j , j 1, , m
,
H1w : w w1, , w m , w i u i , B i1 u i , , B is i u i , i 1, , m,
whereu1, , u m ∈ H0
,
Hi H i ⊕ X i
1⊕ · · · ⊕ X i
s i , H m
i1
Hi , H1/2 H1,H1/2
1.5
u H1/2 m
i1
u iH i
is a subspace of
H 1/2u : u u1, , u m , u i ∈ H i
1/2 , i 1, , m H1
1/2 × · · · × H m
vi Let the linear manifold H0be dense in H 1/2, and let linear manifoldH1be dense in
H.
vii Green’s Identity For arbitrary u, v ∈ H0and t ∈ 0, T, the following identity is
valid:
m
i1
⎡
⎣A i tu i , v iH i ts i
ν1
m
k1
C i kν tu k , B iν v i
X i
ν t
⎤
⎦
i1
⎡
⎣u i , A i tv iH i ts i
ν1
B iν u i ,
m
k1
C i kν tv k
X i t
⎤
⎦.
1.8
Trang 4viii For all u u1, , u m ∈ H0, the following inequality is fulfilled:
c1
m
i1
u i2
H is i
ν1
B iν u i2
X i ν
i1
⎡
⎣A i tu i , u iH i ts i
ν1
m
k1
C i kν tu k , B iν u i
X i
ν t
⎤
⎦ ≤ c2
m
i1
u i2
H i 1/2 ,
1.9
where c1∈ R, c2> 0.
ix For each t ∈ 0, T, an operator pencil
Lt λ : u u1, , u m −→ Lt λu
L t10λu, L t
11λu, , L t
1s1λu, , L t
m0 λu, L t
m1 λu, , L t
L t i0 λu λu i A i tu i , i 1, 2, , m,
L t iν λu λB iν u im
k1
C i kν tu k , ν 1, 2, , s i , i 1, 2, , m. 1.11
x u0
i ∈ H i
0, u1i ∈ H i
1/2 ,m
k1D j kμ u0k 0,m
k1D j kμ u1k 0
i 1, 2, , m, μ 1, 2, , r j , j 1, 2, , m. 1.12
xi f i · ∈ W1
p 0, T; H i , p ≥ 1, i 1, , m,
g iν · ∈ W1
p
0, T; X ν i
Definition 1.1 The function t → u1t, , u m t is called a solution of problem 1.1-1.2 if
the function t → ut u1t, , u m t from 0, T to H0is continuous, and the function
t −→ u1t, B11u1t, , B 1s1u1t, , u m t, B m1 u m t, , B ms m u m t 1.14 from0, T to H is twice continuously differentiable and 1.1-1.2 are satisfied
Theorem 1.2 Let conditions (i)–(xi) are satisfied, then the problem 1.1-1.2 has a unique solution.
Trang 5Proof We define the operator At in the Hilbert space H in the following way:
D At H1,
m
k1
C k11 tu k , ,
m
k1
C1ks
1tu k , , A t m u m ,
m
k1
C m k1 tu k , ,
m
k1
C m ks
m tu k
, t ∈ 0, T, w ∈ H1.
1.15
¨
where wt u1t, B11u1t, , B 1s1u1t, , u m t, B m1 u m t, , B ms m u m t,
Φt f1t, g11t, , g 1s1t, , f m t, g m1 t, , g ms m t,
w0u01, B11u01, , B 1s1u01, , u0m , B m1 u0m , , B ms m u0m
,
w1u11, B11u11, , B 1s1u11, , u1m , B m1 u1m , , B ms m u1m
.
1.17
It is obvious that ifu1t, , u m t is the solution of problem 1.1-1.2, then wt is
the solution of the problem1.16 On the contrary, if
w t ∈ C20, T; H ∩ C1
is the solution of problem 1.16, then wt u1t, B11u1t, , B 1s1u1t, , u m t,
B m1 u m t, , B ms m u m t and u1t, , u m t is the solution of problem 1.1-1.2
w1, w2
Htm
i1
w1i , w2i
H i tm
i1
s i
ν1
B iν u1i , B iν u2i
X i
1, , w l
m , w l
i u l
i , B i1 u l i , , B is i u l i , i 1, 2, , m,u l
1, , u l
m ∈ H0, l 1, 2.
We will prove later the following auxiliary results
Statement 1.3 There exists such c3> 0, that
c−13 w2
Ht ≤ c3w2
Trang 6and the function t → w2
Ht
w, w Ht
Statement 1.4 At is a symmetric operator in Ht for each t ∈ 0, T.
Statement 1.5 At has a regular point for each t ∈ 0, T in R.
At is symmetric and RAt λI Ht, for some λ ∈ R; therefore, for each t ∈
0, T, At is a selfadjoint operator in Ht see 4, chapter x
i1
⎡
⎣A i tu i , u iH i ts i
ν1
m
k1
C i kν tu k , B iν u i
X i
ν t
⎤
⎦
≥ c1w2
Ht ,
1.21
Thus, the operatorA0t Atλ0I is selfadjoint and positive definite, where λ0> c1
¨
w t A0twt − λ0w t Ft,
w 0 w0, w˙0 w1.
1.22
solution w ∈ C20, T; H ∩ C10, T; H 1/2 ∩ C0, T; H1 see 5,6
0,m
k1D j kμ u0k 0i 1, 2, , m; μ 1, 2, , r j,
j 1, 2, , m and B iν are bounded operators from H i
1/2 to X i
ν , ν 1, 2, , s i , i 1, 2, , m.
Therefore,
w0u01, B11u01, , B 1s1u01, , u0m , B m1 u0m , , B ms m u0m
i ∈ H i
1/2andm
k1D kμ j u1
k 0 i 1, 2, , m, μ 1, 2, , r j , j
1, 2, , m, therefore, B iν u1
i ∈ X i
ν ν 1, 2, , s i , i 1, 2, , m Consequently,
w1u11, B11u11, , B 1s1u11, , u1m , B m1 u1m , , B ms m u1m
∈ J,
J
w : w w1, , w m , w i u i , B i1 u i , , B is i u i , u i ∈ H i
1/2 ,
m
k1
D j kμ u k 0, i 1, , m, μ 1, , r j , j 1, , m
.
1.24
Trang 7From the definition of interpolation spacessee 3, chapter 1, 7, chapter 1, we get the following inclusion:
H1⊂ H1/2⊂ H1/2 m
i1
H 1/2 i ⊕ X i
1⊕ · · · ⊕ X i
s i
7, chapter 1, we have that DA1/2
c−1wH1/2≤A1/2
0 tw
A1/2
0 tw2
Ht A0tw, w Ht
i1
⎡
⎣A i tu i , u iH i ts i
ν1
m
k1
C i kν tu k , B iν u i
X i
ν t
⎤
⎦
λ0
m
i1
u i , u iH i ts i
ν1
B iν u i , B iν u iX i
ν t
.
1.27
By virtue of conditionsii, viii, 1.26, and 1.27, we get
H1/2 ≤ cm
i1
u i2
H i 1/2
Let w1 ∈ J By virtue of condition vi, H0 is dense in H 1/2; therefore, there exists a
sequence u p u p1 , , u p m , such that u p∈ H0and
u p − u1
H1
1/2 ⊕···⊕H m 1/2
Hence it follows, that
u p − u q
H1
1/2 ⊕···⊕H m 1/2
Then from1.28 and 1.30 it follows that {w p} is fundamental in H1/2, that is,
w p − w q
H1/2
where w p u p1 , B11u p1 , , B 1s u p1 , , u p m , B m1 u p m , , B ms u p m , p 1, 2,
Trang 8Thus, there existsw ∈ H1/2such that
w p− w
H1/2
On the other hand,H1/2⊂ H1/2, therefore,
w p− w
Hence,
u p − u
H1
1/2 ⊕···⊕H m 1/2
where u u1, , u m From this, by virtue of 1.29, u u1, that is,
wu11, B11u11, , B 1s1u11, , u1m , B m1 u1m , , B ms m u1m
1.2 Proof of Auxiliary Results
Proof of Statement 3 Consider in Hilbert spaceH the equation
whereF f1, f11, , f 1s1, , f m , f m1 , , f ms m ∈ H, λ ∈ R.
equations:
L t i0 λu λu i A i tu i f i , t ∈ 0, T, i 1, 2, , m,
L t iν λu λB iν u im
k1
C i kν tu k g iν , t ∈ 0, T, ν 1, 2, , s i , i 1, 2, , m,
m
k1
D j kμ u k 0, μ 1, 2, , r j , j 1, 2, , m.
1.37
By virtue ofix, problem 1.37 has a solution u u1, , u m ∈ H0 for some λ ∈ R Thus, for each t ∈ 0, T,
Trang 92 Abstract Model of Initial Boundary Value Problem with
Non Stationary Boundary and Transmission Conditions for
the Impulsive Semilinear Hyperbolic Equations
Consider the following initial boundary value problem:
¨u i t A i tu i t f i
t, u t, ˙ut,
B iν ¨u i t m
k1
C i kν tu k t g iν
t, u t, ¨ut,
m
k1
D kμ i u k t 0,
u i 0 u0
i , ˙u i 0 u1
i ,
2.1
where t ∈ 0, T, ν 1, , s i , μ 1, , r i , i 1, , m, ˙u u1, , u m , ¨u ˙u1, , ˙u m , A i t,
B iν , C i
kν t and D i
kμsatisfy all conditions of Theorem1.2
xi Suppose that the nonlinear operators
t, u, ˙u
−→ f i
t, u, ˙u
i1
H 1/2 i
i1
H i
−→ H i ,
t, u, ˙u
−→ g iν
t, u, ˙u
i1
H i
1/2
i1
H i
ν
2.2
0, T, u1, v1, u2, v2 ∈ H 1/2× H,
f i
t1, u1, v1
− f i
t2, u2, v2
H i
≤ c i r
|t1− t2| m
i1
u1
i − u2
i
H i 1/2
v1
i − v2
i
H i
,
g iν
t1, u1, v1
− g iν
t2, u2, v2
X i ν
≤ c iν r
|t1− t2| m
i1
u1
i − u2
i
H i 1/2
v1
i − v2
i
H i
,
2.3
where c i ·, c iν ∈ CR, R, ν 1, , s i , i 1, , m,
rm
i1
2
l1
u l
i
H i 1/2
v l
i
H i
Trang 10
Theorem 2.1 Let conditions (i)–(x) and (xi) be satisfied, then there exists T∈ 0, T, such that the
problem2.1 has a unique solution
u u1, , u m ∈ C
0, T
, H0
∩ C1
0, T
, H 1/2
∩ C2
0, T
, H
Additionally, if
E t m
i1
u i t H i
1/2 ˙u i t H i
i1
u0
i
H i 1/2
u1
i
H i
, t∈0, T
where ϕ · ∈ CR, R, then T T Otherwise, there exists T0∈ 0, T, such that
lim
¨
w A0tw Ft, w, ˙w,
w 0 w0, w˙0 w1,
2.8
where w u1, B11u1, , B 1s1u1, , u m , B m1 u m , , B ms m u m,
w0u01, B11u01, , B 1s1u01, , u0m , B m1 u0m , , B ms m u0m
,
w1u11, B11u11, , B 1s1u11, , u1m , B m1 u1m , , B ms m u1m
,
Ft, w, ˙w λ0w F1t, w, ˙w,
F1t, w, ˙w f1
t, u, ˙u
, g11
t, u, ˙u
, , g 1s1
t, u, ˙u
, ,
f m
t, u, ˙u
, g m1
t, u, ˙u
, , g ms m
t, u, ˙u
.
2.9
Fromxi’, it follows that, for arbitrary t1, t2∈ 0, T, w1, w2∈ H1/2 , z1, z2∈ H,
Ft1, w1, z1
− Ft2, w2, z2
|t1− t2| w1− w2
H1/2
z1− z2
H
where c· ∈ CR, R, r 2
l1w lH z lH
Trang 11Thus, the nonlinear operatorF satisfies the condition of local solvability of the Cauchy problem for the quasilinear hyperbolic equations in Hilbert spacesee 6,9 Taking this into
w ∈ C2
0, T
;H∩ C1
0, T
;H1/2
∩ C0, T
;H1
3 Initial Boundary Value Problem with
Non Stationary Boundary and Transmission Condition for
the Impulsive Semilinear Hyperbolic Equations
Let a1 < a2 < · · · < a m1 We consider in the domain0, T × m
i1a i , a i1 the following mixed problem
¨u i t, x − p i tu
i t, x f i
t, x, u i t, x, u
i t, x, ˙u i t, x, ϕ i
u, ˙u
,
t, x ∈ 0, T × a i , a i1, i 1, 2, , m,
u i t, a i1 u i1t, a i1, i 1, 2, , m − 1, t > 0,
¨u1t, a1 − q0tu
1t, a1 g0
t, ψ0
u, ˙u
, t > 0,
¨u i t, a i1 q i tui t, a i1 − u
i1t, a i1! g i
t, ψ i
u, ˙u
,
i 1, 2, , m − 1, t > 0,
¨u m t, a m1 q m tu
m t, a m1 g m
t, ψ m
u, ˙u
, t > 0,
u i 0, x u0
i x, ˙u i 0, x u1
i x, x ∈ a i , b i , i 1, 2, , m,
3.1
where ˙u i ∂u i /∂t, ui ∂u i /∂x, ¨u i ∂2u i /∂t2, u i ∂2u i /∂x2, u u1, , u m , ˙u
˙u1, , ˙u m , p i , q j , f i , g j , u0
i , u1
be specified below, i 1, , m, j 0, 1, , m.
Recently, differential equations with impulses are great interest because of the needs of modern technology, where impulsive automatic control systems and impulsive computing systems are very important and intensively develop broadening the scope of their applications in technical problems, heterogeneous by their physical nature and functional purposesee 10, chapter 1
Assume that the following conditions are held:
10 p i t ∈ C10, T, q j t ∈ C10, T; p i t > 0, q j t > 0, t ∈ 0, T, i 1, , m, j
0, 1, , m,
20 f i · ∈ C10, T × a i , a i1 × R4, i 1, 2, , m,
30 g j · ∈ C10, T, R, j 0, 1, , m,