Диссертация (1149369), страница 8
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[26]). Íà ãëàäêèõ ïîëÿõâûïîëíåíîLPGT = L.(3.2.33)Äåéñòâèòåëüíî,LPGT w(3.2.28)(3.2.32)(1.2.3)∇κ div PGT w = ∇κ div (w − PJT w) = Lw. v0 ∈ LνT ñïðàâåäëèâî ïðåäñòàâëåíèåËåììà 3.2.5. Íà ãëàäêèõ ïîëÿõ v =0=) ()c ∂1 ∂12− ΛcJ + JΛc v 0 r0 .N L(N ) v r0 =c2 ∂τcJ ∂τ v0Äîêàçàòåëüñòâî. Äëÿ ïðîèçâîëüíîãî ãëàäêîãî v = ∈ LνT èìååì0(TT ∗ 0(3.2.34) 000vvv(3.2.31) (3.2.29) (3.2.33)== LL(N T )∗ = LPGT divθ−1 [c−1 Λc2 v 0 ]divθ−1 [c−1 Λc2 v 0 ]01 ∂ c c2 ∂τ J=∇θ Jc] 1 ∂ c [ ∂] 00−1 −12 02cJv+cJdivdiv[cΛcv]cJ+JΛcvθθ∂τ c2 ∂τ J ∂τ =;[∂][∂] 0c0−1 −12 02cJv + cJdivθ divθ [c Λc v ]∇θ J ∂τ cJ + JΛc v∂τ[∂] [ 12 ∂ c ∂ cJ + JΛc2 v 0 c ∂τ J ∂τ1 − 1c Λ∇−1v0θ TT ∗ (3.2.30) =N L(N )=000][c∂02∇θ J ∂τ cJ + JΛc v[] 0]c[∂1 ∂12− c Λ J ∂τ cJ + JΛc v2.= c ∂τ0Ëåììà äîêàçàíà.543.2.8Îïåðàòîð èçîáðàæåíèÿÎïåðàòîðûNTΠTèITóíèòàðíû; êîìïîçèöèÿI T = ΠT N T óíèòàðíûé îïåðàòîð èçGTíà(3.2.35)FνT (0 < T < T reg ).
I Tíàçûâàåòñÿîïåðàòîðîì èçîá-ðàæåíèÿ; îáðàç h̃ = I T h èçîáðàæåíèåì ïîëÿ h; èçîáðàæåíèå åñòü ïîëå íà âûêðîéêåΘT ,íîðìàëüíîå êΓ. îáðàòíîé çàäà÷å îïåðàòîðITáóäåò èãðàòü êëþ÷åâóþ ðîëü.ÏóñòüN := {g ∈ L2 (Γ, R3 ) | g × ν = 0}åñòü ïðîñòðàíñòâî íîðìàëüíûõ ïîëåé íàΓ (ν íîðìàëü ê(3.1.16) áóäåì ðàññìàòðèâàòü êàê ïðîñòðàíñòâîN-çíà÷íûõΓ).ÏðîñòðàíñòâîFνTôóíêöèé ïåðåìåííîéτ ∈ [0, T ] :FνT = L2 ([0, T ]; N) ;âFνT(3.2.36)äåéñòâóåò ñåìåéñòâî ñðåçàþùèõ ïðîåêòîðîâ(X ξ f )(τ ) :=f (τ ) , 0 6 τ 6 ξ ;0 ,ξ<τ 6T(0 6 ξ 6 T ).Ëåììà 3.2.6. Ñïðàâåäëèâî ðàâåíñòâîI T Qξ = X ξ I T .Äîêàçàòåëüñòâî.(3.2.37) ïðîñòðàíñòâå ïðîäîëüíûõ ïîëåéLνTâûäåëèì ðàñøèðÿþùååñÿñåìåéñòâî ïîäïðîñòðàíñòâLνξ := {v ∈ LνT | supp v ⊂ Ωξ } ,÷åðåçYξîáîçíà÷èì ïðîåêòîð âïîäîáëàñòüΩξ .LνTíàLνξ ;0 6 ξ 6 T < T reg ;åãî äåéñòâèå ñâîäèòñÿ ê ñðåçêå ïîëÿ íàÀíàëîãè÷íî [33], ìîæíî ïîêàçàòü, ÷òîN T Qξ = Y ξ N T ,0 6 ξ 6 T < T reg ;55òåïåðü(3.2.37)I T = ΠT N TèÿâëÿåòñÿΠTñëåäñòâèåìýòîãîðàâåíñòâàèîïðåäåëåíèÿîïåðàòîðîâ(ñì.
(3.1.19)). Ëåììà äîêàçàíà.Òàêæå îòìåòèì, ÷òî áëàãîäàðÿ ñâîéñòâó (3) ëåììû 3.1.1, ñîîòâåòñòâèåh → IT hñîõðàíÿåò ãëàäêîñòü:I T [G T ∩ C ∞ (ΩT ; R3 )] = FνT ∩ C ∞ (ΘT ; R3 ) ;ïðè ýòîì âûïîëíåíî ñîîòíîøåíèå(I T h)|τ =0 = κ0 hν |Γ ,cκ0 := κ|Γ =√c0(3.2.38), ñëåäóþùåå èç()ξ→0(N T h)|Γξ = {hν − Λ∇θ−1 hθ ν}|Γξ −→ hν |Γè îïðåäåëåíèÿ îïåðàòîðà3.2.9ÎïåðàòîðÎïðåäåëèì îïåðàòîðïîòåíöèàëüíûõ ïîëÿõΠT .I T (∇κ div)(I T )∗LT : G T → G T ,hDomLT = G T ∩ C ∞ (ΩT ) ,êîòîðûé íà ãëàäêèõäåéñòâóåò ïî ïðàâèëó:LT h := Lh = ∇κ div h .ÎòîáðàæåíèåITèíäóöèðóåò âFνTîïåðàòîðL̃T := (I T )LT (I T )∗ñ Dom(3.2.39)L̃T = FνT ∩ C ∞ (ΘT ). Íèæå ìû îïèñûâàåì ïðåäñòàâëåíèå L̃T , èãðàþùåå âàæíóþðîëü â îáðàòíîé çàäà÷å.ÎïåðàòîðîïåðàòîðîâS : FνT → FνTáóäåì íàçûâàòüS(τ ) : N → N(0 6 τ 6 T ),ïîñëîéíûì,åñëè åãî îïðåäåëÿåò ñåìåéñòâî11à ñàì îí äåéñòâóåò ïî ïðàâèëó:(Sf )(τ ) = S(τ )f (τ ), τ ∈ [0, T ] .11 çäåñü,â ñîîòâåòñòâèè ñ ïðåäñòàâëåíèåì (3.2.36), f ïîíèìàåòñÿ êàêN-çíà÷íàÿ ôóíêöèÿ îò τ56Ïóñòüσ⊂Γ îêðåñòíîñòü, êîòîðàÿ ïîêðûâàåòñÿ ëîêàëüíûìè êîîðäèíàòàìèr̃0 áàçèñíîå ïîëå â σ × [0, T ] ⊂ ΘT , êîòîðîå íå çàâèñèò îò τγ 1, γ 2 ;è îïðåäåëÿåòñÿ ôîðìóëîér̃0 (γ, τ ) = r0 (γ, 0) ;f = f 0 r̃0åñòü ïðåäñòàâëåíèå ïîëÿf ∈ FνTíàσ × [0, T ] .Òåîðåìà 3.2.1.
Ïðè 0 < T < T reg äëÿ ãëàäêîãî íîðìàëüíîãî ïîëÿ f = f 0 r̃0 íà σ×[0, T ] ,ñïðàâåäëèâî ïðåäñòàâëåíèå[L̃T f = ∂2∂τ 2− Λ̃2]f0 + S̃f ,(3.2.40)0√√Jc −1â êîòîðîì Λ̃ := πΛcπ , à S̃ åñòü ïîñëîéíûé ïñåâäîäèôôåðåíöèàëüíûé îïåcJðàòîð íà âûêðîéêå ΘT , ïîðÿäêà íå âûøå 1.Äîêàçàòåëüñòâó òåîðåìû ïðåäïîøë¼ì íåñêîëüêî ëåìì.
Íàïîìíèì, ÷òî îïåðàòîðâL2 (ΩT )ìû íàçûâàåì ïîñëîéíûì, åñëè îí äåéñòâóåò ïî ïðàâèëó(Kφ)Γξ := K(ξ)[φΓξ ] ,ãäåK(ξ)K îïåðàòîðû â0 < ξ 6 T,L2 (Γξ ).Ëåììà 3.2.7. Äëÿ ãëàäêîé â ΩT ôóíêöèè χ ñïðàâåäëèâî ðàâåíñòâî∂∂Λχ − Λχ= K,∂τ∂τ(3.2.41)â êîòîðîì K åñòü ïîñëîéíûé îïåðàòîð òàêîé, ÷òî âñå K(ξ) ñóòü ÏÄÎ ïîðÿäêà 1.Ïðåäñòàâëåíèå (3.2.41) ëåãêî ñëåäóåò èç ôîðìóëû (B.4) ëåììû B.2 ïðèëîæåíèÿ B.â [31]. Îòìåòèì òàêæå, ÷òî îïåðàòîðKîêàçûâàåòñÿ ïñåâäîäèôôåðåíöèàëüíûì èç-çàòîãî, ÷òî òàêîâûìè ÿâëÿþòñÿ îïåðàòîðû Êàëüäåðîíà, îïðåäåëÿþùèåΛ:êàæäûéΛξåñòü ýëëèïòè÷åñêèé ÏÄÎ ïîðÿäêà 1 (ñì., íàïðèìåð, [35]). v0 ∈ LνTËåììà 3.2.8. Äëÿ ëþáîãî ãëàäêîãî ïîëÿ v =0[ 2] ∂20 ∂τ 2 − Λ̄ v T TT ∗N L (N ) v = + Sv ,0(3.2.42)57ãäåΛ̄ := Λ∗ c = 1c Λc2 ,Äîêàçàòåëüñòâî.àS ïîñëîéíûé ÏÄÎ ïîðÿäêà íå âûøå 1. âûêëàäêå, êîòîðàÿ ïðèâîäèòñÿ íèæå, çíà÷êîì∼ îòìå÷àþòñÿ ïå-ðåõîäû ñ îòáðàñûâàèåì îïåðàòîðîâ áîëåå íèçêîãî ïîðÿäêà. Äëÿ ïðîèçâîëüíîãî ãëàäêîãîv = v 0 r0 ∈ LνTèìååì) ()11 ∂c ∂2N L (N ) v r0 =− ΛcJ + JΛc v 0 r0 =c2 ∂τcJ ∂τ()1 ∂ c ∂1 ∂1 c ∂122=cJ + 2 cΛc − ΛcJ − ΛcΛc v 0 r0 ∼2c ∂τ J ∂τc ∂τc J ∂τc()1 ∂ 2 ∂1 ∂1 2 ∂122∼c+Λc − Λc− ΛcΛc v 0 r0 ∼c2 ∂τ ∂τc ∂τc∂τc( 2[])( 2)∂∂1 ∂11(3.2.41)22 ∂202∼+Λc − Λc− ΛcΛc v r0 ∼− ΛcΛc v 0 r0 .∂τ 2 c ∂τ∂τc∂τ 2 cTÎáîçíà÷àÿ(3.2.34)T ∗ 0T(Λ̄ := 1c Λc2 è âñïîìèíàÿ, ÷òî Λ∗ = 1c Λc, ïðèõîäèì ê (3.2.42).
Ëåììà äîêàçàíà.Òåïåðü ìû ãîòîâû çàâåðøèòü äîêàçàòåëüñòâî òåîðåìû 3.2.1. Ïî îïðåäåëåíèþ(3.1.19), îïåðàòîðΠT : LνT → FνTäåéñòâóåò òàêΠT v = κπv,ãäå, ñîãëàñíî (3.1.18),cκ=c0Ïîëüçóÿñü óíèòàðíîñòüþ îïåðàòîðàL̃T(3.2.39)=(I T )LT (I T )∗(3.2.35)=ΠT ,√c(3.2.43)J.J0(3.2.44)çàïèøåìΠT N T LT (N T )∗ (ΠT )∗(3.2.43)=κπN T LT (N T )∗ π −1 κ−1 .Îñòàëîñü âîñïîëüçîâàòüñÿ ëåììîé 3.2.8. Èìååì:(L̃ = κπT)∂22− Λ̄ π −1 κ−1 + (I T )S(I T )∗ .∂τ 2Ïîñêîëüêó íà ïðîäîëüíûõ ïîëÿõ∂π∂τ∂= π ∂τD∂τ=(3.2.45)∂, òî ðàâåíñòâî (3.1.12) ïðèîáðåòàåò âèä∂τ; ïîýòîìó∂ 2 −1 −1∂ 2 −1∂2κπ 2 π κ = κ 2 κ ∼ 2 .∂τ∂τ∂τ(3.2.46)Äàëåå, îáîçíà÷èìΛ̃2 := κπ Λ̄2 π −1 κ−1(3.1.10)=πκΛ̄2 κ−1 π −1 ,(3.2.47)58ãäå−1 −1 (3.2.44)Λ̃ := πκΛ̄κ π=√1π cJ Λ̄ √ π −1cJÓ÷èòûâàÿ (3.2.46) è (3.2.47) è îáîçíà÷àÿ â (3.2.45)(f= f 0 r̃0 ) :(TL̃ f =ëåãêî âèäåòü, ÷òîΛ̄= 1c Λc2=√πJΛcc√c −1π .JS̃ := (I T )S(I T )∗ , ïðèõîäèì ê (3.2.40))∂22− Λ̃ f 0 r̃0 + S̃f ;∂τ 2(3.2.48)S̃ ïîñëîéíûé ÏÄÎ íà âûêðîéêå ïîðÿäêà íå âûøå 1.
Òåîðåìà 3.2.1Λ ïîñëîéíûé îïåðàòîð, â êîòîðîì êàæäûéäîêàçàíà.Îòìåòèì, ÷òîåñòü ñêàëÿðíûé ÏÄÎ 1-ãî ïîðÿäêà c ãëàâíûì ñèìâîëîìΛξ ,ñîãëàñíî (3.2.10),|k|g ; ïîëüçóÿñü ýòèì, à òàê æåñâîéñòâàìè ãëàâíûõ ñèìâîëîâ ïðè êîìïîçèöèè îïåðàòîðîâ è óìíîæåíèè èõ íà ôóíêöèè, çàêëþ÷àåì, ÷òî ðåçóëüòàò òåîðåìû 3.2.1 äîïóñêàåò ñëåäóþùóþ èíâàðèàíòíóþôîðìóëèðîâêó â òåðìèíàõ ïñåâäîäèôôåðåíöèàëüíûõ îïåðàòîðîâ.Òåîðåìà 3.2.2. Ñïðàâåäëèâî ïðåäñòàâëåíèåL̃T =∂2+ H,∂τ 2(3.2.49)â êîòîðîì H åñòü ïîñëîéíûé îïåðàòîð òàêîé, ÷òî êàæäûé H(τ ) :0 < τ 6 T , Dom H(τ ) =N∩C∞N → N,(Γ, R3 ) åñòü ÏÄÎ âòîðîãî ïîðÿäêà ñ ìàòðè÷íûìãëàâíûì ñèìâîëîìSymbH(τ ) (γ, k1 , k2 ) = −c2 (γ, τ )|k|2g Idγ = −|k |2h Idγ ,(3.2.50))1/2(; k1 , k2 ïåðåìåííûå, äâîéñòâåííûå ê γ 1 ; γ 2 ; Idγ ãäå |k|h := hαβ (γ 1 , γ 2 , τ )kα kβòîæäåñòâåííûé îïåðàòîð íà êîêàñàòåëüíîì ïðîñòðàíñòâå Tγ∗ Γ; γ = (γ 1 , γ 2 ) ∈ Γ.Îòìåòèì, ÷òî âòîðîå ðàâåíñòâî â (3.2.50) ñëåäóåò èç (3.1.5), ïîñêîëüêó.c2 g αβ = hαβ593.3Äèíàìèêà3.3.1Ïðÿìàÿ çàäà÷à.
Îïåðàòîð óïðàâëåíèÿÔèêñèðóåì ïðîèçâîëüíîåíàïîìíèì, ÷òîçíà÷åíèÿìè âè ðàññìîòðèì çàäà÷ó (3.2.25)(3.2.27)htt − Lh = 0âQT ,(3.3.1)h|t=0 = ht |t=0 = 0âΩ,(3.3.2)hν = fíàL = ∇κ div, νh = hf (x, t)à ðåøåíèåT >0 íîðìàëü êΣT ;Γ, hν = (h·ν)ν , f ∈ FνT ⊂ F T(3.3.3) óïðàâëåíèå,ìû ðàññìàòðèâàåì êàê çàâèñÿùóþ îò âðåìåíè ôóíêöèþ ñîGT . ñîîòâåòñòâóþùåé çàäà÷å äèíàìè÷åñêîé ñèñòåìåíèå" ðåàëèçóåòñÿαTpîòîáðàæåíèå "âõîä ñîñòîÿ-îïåðàòîðîì óïðàâëåíèÿ W T : FνT → G T , Dom W T = MTνW Tf = hf (· , T ) .12(3.3.4)Íåòðóäíî ïîêàçàòü, ÷òî îí äîïóñêàåò çàìûêàíèå.
Îòìåòèì òàêæå, ÷òî ïðè âðåìåíàõT < T∗13îïåðàòîð óïðàâëåíèÿ èíúåêòèâåí:Ker W T = {0}(äîêàçàòåëüñòâî àíàëî-ãè÷íî ïðåäñòàâëåííîìó â [15]).3.3.2ÓïðàâëÿåìîñòüÌíîæåñòâîGT := Ran W T ⊂ G Tíàçûâàåòñÿäîñòèæèìûìê ìîìåíòó âðåìåíèT.Ïðåäëîæåíèå 3.3.1. Ïðè âðåìåíàõ T < T reg ñïðàâåäëèâî ñîîòíîøåíèåGT = G T(3.3.5)(çàìûêàíèå â ìåòðèêå H).12 MTν= FνT ∩ MT , ñì. (3.1.17)÷òî T ∗ åñòü âðåìÿ çàïîëíåíèÿ îáëàñòè Ω âîëíàìè, èäóùèìè îò ãðàíèöû: ñì.
ðàçäåë13 íàïîìíèì,1.1.160Îíî âûâîäèòñÿ âïîëíå àíàëîãè÷íî ñîîòíîøåíèþ (2.2.17).Èç (3.3.5) ñëåäóåò, ÷òî ëþáîå ïîòåíöèàëüíîå ïîëå â ïîäîáëàñòèìèðîâàòü âîëíàìèêàê îhf (· , T )L2 -íîðìå.âïðèáëèæåííîé óïðàâëÿåìîñòèFνTÂî âíåøíåì ïðîñòðàíñòâåñèñòåìû (3.3.1)(3.3.3).ðàññìîòðèì ñåìåéñòâî ïîäïðîñòðàíñòâ0 6 ξ 6 T,äëÿèìååì âêëþ÷åíèåsupp hf (·, T ) ⊂ Ωξ ,ò.å.Çàïàçäûâà-supp hf (·, ξ) ⊂ Ωξè ñòàöèîíàðíîñòè ñèñòåìû (3.3.1)(3.3.3) (íåçàâèñèìîñòèf ∈ FνT,ξ(3.3.6)çàïàçäûâàþùèìè óïðàâëåíèÿìè (FνT,0 = {0}, FνT,T = FνT ).íèå óïðàâëåíèÿ ïðèâîäèò ê çàïàçäûâàíèþ âîëíû: ïî ñâîéñòâó(0 < ξ 6 T )ìîæíî àïïðîêñè- òåîðèè óïðàâëåíèÿ îá òîì ñâîéñòâå ãîâîðÿò,FνT,ξ := {f ∈ FνT f (·, t) = 0, 0 6 t < T − ξ},îáðàçîâàííûõΩTLîò âðåìåíè)hf (·, T ) ⊂ G ξ .Ââåä¼ì ðàñøèðÿþùååñÿ ñåìåéñòâî äîñòèæèìûõ ìíîæåñòâGξ := W T FνT,ξ ⊂ G ξ .ÏðîåêòîðûPξâGTíàGξíàçûâàþòñÿâîëíîâûìè;äîïîëíèòåëüíûå ïðîåêòîðû ñóòüP⊥ξ := IGT − P ξ .(3.3.7)Ñòàöèîíàðíîñòü ñèñòåìû è ñîîòíîøåíèå (3.3.5) ïðèâîäÿò ê ðàâåíñòâóGξ = G ξ ,(3.3.8)èç êîòîðûõ, â ñâîþ î÷åðåäü, ñëåäóåòP ξ = Qξ ,ξ(Q ïðîåêòîð âGTÐàçóìååòñÿ, êàêíàQξ ,Gξ:P⊥ξ = Qξ⊥(0 6 ξ 6 T < T reg ) .(3.3.9)ñì.















