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Nombre de lectures | 23 |
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nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)hTerpofooNnocvnxeOntheuniformcontrollabilityofviscous
perturbationsofscalarconservationlaws
MatthieuLe´autaud
LaboratoireJacquesLouisLions,UPMCParis6
leautaud@ann.jussieu.fr
acesaWorkshopControlofparabolicequationsandsystems,applicationstofluids,
ControlofPartialandDifferentialEquationsandApplicationsTrimester
November,16.2010
dnocorllraeis
nIrtoudcitnohTerpIntroduction
oTheproblem
lbmehTerTheresult(convexcase)
Theproof
Firststep
Secondstep
selutc(noevxaces)Outline
Nonconvexcaseandcorollaries
hTerpofooNnocvnxeacesnadocorllraeis
nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)hTerpofoIntroduction:anexample
Coron-Guerrero’05
oNnocn
u
t
+
Mu
x
−
ε
u
xx
=0in(0
,
T
)
×
(0
,
L
)
,
u
|
t
=0
=
u
0
in(0
,
L
)
,
u
|
x
=0
=
g
(
t
)and
u
|
x
=
L
=
0
in(0
,
T
)
.
evxcTheorem(Fattorini-Russell’71,FursikovImanuvilov’96)
∀
T
>
0
,
∀
u
0
∈
L
2
(0
,
L
)
,
∃
g
=
g
ε
∈
L
2
(0
,
T
)
satisfying
εk
g
k
L
2
(0
,
T
)
≤
C
(
T
,
L
,
M
,
ε
)
k
u
0
k
L
2
(0
,
L
)
,
s.t.u
|
t
=
T
=0
.
Moreover,C
(
T
,
L
,
M
,
ε
)=
C
0
(
T
,
L
,
M
)exp
C
1
(
T
ε
,
L
,
M
)
.
saenadocorllraeis
nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)hTerpofoIntroduction:anexample
Coron-Guerrero’05
However,forthelimitproblem(
ε
=0)for
M
>
0:
u
t
+
Mu
x
=0in(0
,
T
)
×
(0
,
L
)
,
u
|
t
=0
=
u
0
in(0
,
L
)
,
u
|
x
=0
=
g
(
t
)in(0
,
T
)
.
oNnocvnxeacesnadocTheorem
SupposethatM
>
0
,then,
∀
T
>
ML
,
∀
u
0
∈
L
2
(0
,
L
)
,taking
g
=0
impliesu
|
t
=
T
=0
.(and
k
g
k
L
2
=0
)
orllraeis
nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)hTerpofoIntroduction:anexample
Coron-Guerrero’05
Theorem(Coron-Guerrero’05)
oNnocvnxeSupposethatM
>
0
.
(i)
IfT
<
ML
,then
∃
C
0
,
C
1
>
0
s.t.forallcontrol
g
=
g
ε
,
C1k
g
ε
k
L
2
(0
,
T
)
≥
C
0
exp
ε
k
u
0
k
L
2
(0
,
L
)
(ii)
IfT
>
4
.
3
ML
,then
∃
C
0
,
C
1
>
0
and
∃
g
=
g
ε
s.t.
Tthreeu(ffiorrtslaplraTtC1k
g
ε
k
L
2
(0
,
T
)
≤
C
0
exp
−
ε
k
u
0
k
L
2
(0
,
L
)
o>ftLMeh)oCor-nuGreerorocjnceuter:(ii)hsuolacdesahnodlcdroloalirse
Theproblem
(3)
)2(
(1)
u
|
x
=0
=
g
0
(
t
)and
u
|
x
=
L
=
g
L
(
t
)
in(0
,
T
)
.
u
|
t
=0
=
u
0
in(0
,
L
)
,
u
t
+[
f
(
u
)]
x
−
ε
u
xx
=0in(0
,
T
)
×
(0
,
L
)
,
Semilinearparabolicequation
.Tu=T=t|usefisitas)2(,)3(,)1(fonoitulosehttahtosεLg=Lgdnaε0g=0g?∃,Tutegratadna,0>T,0unevig:melborpytiliballortnoCseirallorocdnaesacxevnocnoNfoorpehT)esacxevnoc(tluserehTmelborpehTnoitcudortnI
nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)TTheproblem
Semilinearparabolicequation
ehrpofooNnu
t
+[
f
(
u
)]
x
−
ε
u
xx
=0in(0
,
T
)
×
(0
,
L
)
,
u
|
t
=0
=
u
0
in(0
,
L
)
,
ocnu
|
x
=0
=
g
0
(
t
)and
u
|
x
=
L
=
g
L
(
t
)in(0
,
T
)
.
evxacesnadocr(1)
)2(
(3)
Controllabilityproblem:given
u
0
,
T
>
0,andatarget
u
T
,
∃
?
g
0
=
g
0
ε
and
g
L
=
g
L
ε
sothatthesolutionof(1),(3),(2)satisfies
u
|
t
=
T
=
u
T
.
loalirse
foorpehT)esacxevnoc(tluserehTmelborpehTnoitcudortnITheproblem
,)1(fonoitulosehttahtos
(Globalexact)controllabilityproblem:given
u
0
,
T
>
0,anda
target
u
T
,
∃
?
g
0
=
g
0
ε
and
g
L
=
g
L
ε
sothatthesolutionof(1),
(3),(2)satisfies
u
|
t
=
T
=
u
T
.
.εCpxe+0→ε∼”tsoc“:snoitauqecilobaraprofsmelborpytiliballortnoctcaxelacollausU.C≤)T,0(∞LkεLgk+)T,0(∞Lkε0gk.e.i,+0→εsa”tsoc“dednuobahtiwtiod:melborpytiliballortnoc)tcaxelabolg(mrofinUseirallorocdnaesacxevnocnoN
.εCpxe+0→ε∼”tsoc“:snoitauqecilobaraprofsmelborpytiliballortnoctcaxelacollausUTheproblem
k
g
0
ε
k
L
∞
(0
,
T
)
+
k
g
L
ε
k
L
∞
(0
,
T
)
≤
C
.
Uniform
(globalexact)controllabilityproblem:doitwitha
bounded“cost”as
ε
→
0
+
,i.e.
(Globalexact)controllabilityproblem:given
u
0
,
T
>
0,anda
target
u
T
,
∃
?
g
0
=
g
0
ε
and
g
L
=
g
L
ε
sothatthesolutionof(1),
(3),(2)satisfies
u
|
t
=
T
=
u
T
.
seirallorocdnaesacxevnocnoNfoorpehT)esacxevnoc(tluserehTmelborpehTnoitcudortnI
nIrtoudcitnohTerpboelmhTeerustlc(noevxaces)TTheproblem
ehrpofooNnocvnxeacesnad(Globalexact)controllabilityproblem:given
u
0
,
T
>
0,anda
target
u
T
,
∃
?
g
0
=
g
0
ε
and
g
L
=
g
L
ε
sothatthesolutionof(1),
(3),(2)satisfies
u
|
t
=
T
=
u
T
.
Uniform
(globalexact)controllabilityproblem:doitwitha
bounded“cost”as
ε
→
0
+
,i.e.
k
g
0
ε
k
L
∞
(0
,
T
)
+
k
g
L
ε
k
L
∞
(0
,
T
)
≤
C
.
Usuallocalexactcontrollabilityproblemsforparabolicequations:
C“cost”
∼
ε
→
0
+
exp
.
ε
ocorllraeis