Диссертация (1136178), страница 31
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Òîãäà èç ñîîòíîøåíèÿ (3.61) íàõîäèì, ÷òî= 142. Ýòîìó çíà÷åíèþ σ ñîîòâåñòâóåò îäíîïàðàìåòðè÷åñêîåïèñàíî â âèäå(2)σ1ñåìåéñòâî ðåøåíèé (3.46), êîýôôèöèåíòû êîòîðîãî èìåþò âèäsin α(2)c0,1 = √ ,2Çäåñü(2)c1,1 = cos α,(c0 + c2 )2 =σ(3.73)α ∈ R. ñëó÷àå, åñëèäëÿsin α(2)c2,1 = − √ .238,39ñíîâà ïîëó÷àåì çíà÷åíèå (3.70). Åìó ñîîòâåñòâóåò îäíîïà-ðàìåòðè÷åñêîå ñåìåéñòâî ðåøåíèé (3.46), êîýôôèöèåíòû êîòîðîãîèìåþò âèä(2)c0,01=√39√√√ (2) 2 5138 √38(2)+ 10 cos α , c1,0 = √ sin α, c2,0 = √−23939 2261√− 10 cos α .Çäåñüα ∈ R.Îòìåòèì, ÷òî åñëèíûå âûøå ïðèc1 = 0(3.74)(2)σ = σ0è(2)σ = σ1, òî ïîñòðîåí-ðåøåíèÿ ñèñòåìû (3.58) (3.60) ñîäåðæàòñÿ âîäíîïàðàìåòðè÷åñêèõ ñåìåéñòâàõ (3.74), (3.73).ÄîêàçàíàÒåîðåìà 3.4.(3.25),Ïðè p = 2 ñîáñòâåííûå çíà÷åíèÿ çàäà÷è(3.24),îòâå÷àþùèå âåùåñòâåííûì ñîáñòâåííûì ôóíêöèÿì, èìå-þò âèä(0.35), (3.70), (3.66).Ñîîòâåòñòâóþùèå ñîáñòâåííûåôóíêöèè îïðåäåëÿþòñÿ ðàâåíñòâàìè1.6.(3.46), (3.74), (3.73), (3.67).Ñïåêòðàëüíàÿ çàäà÷à íà ïîäïðîñòðàíñòâåH2 .Êîìïëåêñíûå ðåøåíèÿÏåðåéäåì ê ïîñòðîåíèþ êîìïëåêñíûõ ðåøåíèé ñèñòåìû (3.53) (3.56).
 ñèëó çàìå÷àíèÿ 3.3. ìû ìîæåì ñ÷èòàòü, ÷òîc1 ∈ R. Ïîýòîìóïîëîæèì(2)c0 =| c0 | eiϕ0 ,Ïîäåëèì äàëåå (3.53) íà(2)c1 =| c1 |,eiϕ0 , (3.55) íà eiϕ2(2)c2 =| c2 | eiϕ2 .è ïðèðàâíÿåì â óðàâíåíè-ÿõ (3.53) (3.55) ê íóëþ âåùåñòâåííûå è ìíèìûå ÷àñòè.  ðåçóëüòàòåïîëó÷àåì ñèñòåìó−σ | c0 | +2471| c0 |3 + | c0 |2 | c2 | cos (ϕ2 − ϕ0 ) + 153 | c1 |2 | c0 | −221343− | c1 |2 | c2 | cos (ϕ2 − ϕ0 )+ | c2 |2| c0 | + | c2 | ×22× cos (ϕ2 − ϕ0 ) − 30 | c0 || c1 |2 cos2 ϕ0 − 18 | c2 || c1 |2 cos ϕ2 cos ϕ0 ++2 | c0 || c2 | cos (ϕ2 − ϕ0 )| c0 | 9− | c2 | cos (ϕ2 − ϕ0 ) = 0,22(3.75)| c1 | {−σ + 153 | c0 |2 +142 | c1 |2 +153 | c2 |2 −−2 | c0 || c2 | cos (ϕ2 − ϕ0 ) − 2 | c0 | cos ϕ0 (15 | c0 | cos ϕ0 ++9 | c2 | cos ϕ2 ) − 2 | c2 | cos ϕ2 (9 | c0 | cos ϕ0 + 15 | c2 | cos ϕ2 )} = 0,2623431| c0 | cos (ϕ2 − ϕ0 ) +| c2 | + | c1 |2 ×221× − | c0 | cos (ϕ2 − ϕ0 ) + 153 | c2 | + | c2 |2| c0 | cos (ϕ2 − ϕ0 )+2247+| c2 | − 18 | c0 || c1 |2 cos ϕ0 cos ϕ2 − 30 | c2 || c1 |2 cos2 ϕ0 +29| c2 | +2 | c0 || c2 | cos (ϕ2 − ϕ0 ) − | c0 | cos (ϕ2 − ϕ0 ) += 0,22−σ | c2 | + | c0 |2(3.76)| c0 |2 + | c1 |2 + | c2 |2 = 1,(3.77)| c0 |2|c2 |22|c2 | sin (ϕ2 − ϕ0 )− |c1 | +− 9|c0 ||c2 | cos (ϕ2 − ϕ0 ) +22+ | c1 |2 sin ϕ0 (30 | c0 | cos ϕ0 + 18 | c2 | cos ϕ2 ) = 0,(3.78)|c0 |2|c2 |22|c0 | sin (ϕ2 − ϕ0 )− |c1 | +− 9|c0 ||c2 | cos (ϕ2 − ϕ0 ) −22− | c1 |2 sin ϕ2 (18 | c0 | cos ϕ0 + 30 | c2 | cos ϕ2 ) = 0,(3.79)| c1 | {| c0 | sin ϕ0 (5 | c0 | cos ϕ0 + 3 | c2 | cos ϕ2 )++ | c2 | sin ϕ2 (3 | c0 | cos ϕ0 + 5 | c2 | cos ϕ2 )} = 0.(3.80)Óðàâíåíèå (3.80) çäåñü ìîæíî îòáðîñèòü, òàê êàê îíî ÿâëÿåòñÿ ëèíåéíîé êîìáèíàöèåé (3.78), (3.79).Àíàëèç óðàâíåíèé (3.78), (3.79) ïîêàçûâàåò, ÷òî êîìïëåêñíûåðåøåíèÿ ñïåêòðàëüíîé çàäà÷è íà ïîäïðîñòðàíñòâåH2ìîãóò ñóùå-ñòâîâàòü â ñëåäóþùèõ ïÿòè ñëó÷àÿõ.c1 = 0.2 ñëó÷àé.| c2 |= 0, | c0 |6= 0, ϕ0 = ±π/2.3 ñëó÷àé.| c0 |= 0, | c2 |6= 0, ϕ2 = ±π/2.4 ñëó÷àé.ϕ0 = ϕ2 = ±π/2.5 ñëó÷àé.| c0 |=| c2 |6= 0, ϕ2 = −ϕ0 .Ðàññìîòðèì ñëó÷àé 1.
Ïóñòü c1 = 0. Òîãäà èç1 ñëó÷àé.óðàâíåíèé (3.77),(3.78) ñëåäóåò, ÷òîcos (ϕ2 − ϕ0 ) =118 | c0 || c2 |.(3.81)263( Ïðèsin (ϕ2 − ϕ0 ) = 0 ñíîâà ïðèõîäèì ê âåùåñòâåííûì ðåøåíèÿì.)Äàëåå ïîäñòàâèì ïðàâóþ ÷àñòü (3.81) â (3.75), (3.76).  ðåçóëüòàòåïîëó÷àåì ñèñòåìó| c0 | {−σ +9247+ | c2 |2 48 −}+2(18 | c0 || c2 |)2+ | c2 || c0 |+112 | c0 || c2 |136 | c0 || c2 |+−| c2 | = 0,18 | c0 || c2 | + | c2 | {−σ+18 | c0 |993432−+|c|−48+} = 0,22(18 | c0 || c2 |)2(18 | c0 || c2 |)2| c0 |2 + | c2 |2 = 1,êîòîðàÿ ñâîäèòñÿ ê ðåøåíèþ ñëåäóþùèõ óðàâíåíèéσ + 48 | c2 |2 =1343+,182σ − 48 | c2 |2 =1247+.182(3.82)Èç (3.82) íàõîäèì, ÷òî5(2)σ5 = 147 + ,9√| c0 |=| c2 |= 1/ 2,è, ñëåäîâàòåëüíî,(3.83)cos (ϕ2 − ϕ0 ) = 1/9.Òàêèìîáðàçîì, ñîîòâåòñòâóþùèå (3.83) êîýôôèöèåíòû ðàçëîæåíèÿ (3.46)èìåþò âèä(2)c0,5√1 ± 4 5i√=,9 2(2)c1,5 = 0,1(2)c2,5 = √ .2(3.84)Îñòàëüíûå ñëó÷àè ðàññìàòðèâàþòñÿ àíàëîãè÷íî.
Âî âòîðîìñëó÷àå íàõîäèì ÷èñëî(2)σ4 = 145 −181(3.85)264è êîýôôèöèåíòû√(2)c0,4√22i=±,9(2)c1,4 =59,9(2)c2,4 = 0.(3.86) òðåòüåì ñëó÷àå íàõîäèì ÷èñëî (3.85) è êîýôôèöèåíòû√√(2)c0,4= 0,(2)c1,4=59,9(2)c2,4=±22i.9(3.87) ÷åòâåðòîì ñëó÷àå íàõîäèì ÷èñëî(2)σ3 = 145 −133(3.88)è êîýôôèöèåíòû(2)c0,3(2)c0,3√√± 5 + 24i√=,66√√± 5 − 24i√=,66√8(2)c1,3 = √ ,66√8(2)c1,3 = √ ,66√√±5−24i(2)√c2,3 =;66√√± 5 + 24i(2)√c2,3 =.66(3.89)(3.90)Íàêîíåö, â ïÿòîì ñëó÷àå íàõîäèì äâà ÷èñëà (3.83), (3.88), à òàêæåêîýôôèöèåíòû(2)c0,5√5i=± √ ,3 2(2)c1,52= ,3(2)c2,5√5i=± √ .3 2(3.91)è(2)c0,3(2)c0,3√√± 5 + 24i√=,66√√± 5 − 24i√=,66√8(2)c1,3 = √ ,66√8(2)c1,3 = √ ,66√√±5−24i(2)√c2,3 =;66√√±5+24i(2)√c2,3 =.66(3.92)(3.93)ÑïðàâåäëèâàÒåîðåìà 3.5.(3.25),âèäÏðè p = 2 ñîáñòâåííûå çíà÷åíèÿ çàäà÷è(3.24),îòâå÷àþùèå êîìïëåêñíûì ñîáñòâåííûì ôóíêöèÿì, èìåþò(0.35), (3.88), (3.85), (3.83).Ñîîòâåòñòâóþùèå ñîáñòâåííûå265ôóíêöèè îïðåäåëÿþòñÿ ðàâåíñòâàìè(3.46), (3.92), (3.93), (3.89),(3.90); (3.86), (3.87); (3.84), (3.91). 2.Êâàçèêëàññè÷åñêàÿ àñèìïòîòèêà ñïåêòðàäâóìåðíîãî îïåðàòîðà Õàðòðè âáëèçèâåðõíèõ ãðàíèö ñïåêòðàëüíûõ êëàñòåðîâ.2.1.Ââåäåíèå ê 2Ðàññìîòðèì çàäà÷ó íà ñîáñòâåííûå çíà÷åíèÿ (0.40), (0.41) äëÿíåëèíåéíîãî îïåðàòîðà Õàðòðè âëÿòîð (0.42),ε>0L2 (R2 ), ãäå H äâóìåðíûé îñöèë- ìàëûé ïàðàìåòð.
Äëÿ ïîñòðîåíèÿ àñèìïòîòè-÷åñêèõ ðåøåíèé âîñïîëüçóåìñÿ òåì, ÷òî â ïîëÿðíûõ êîîðäèíàòàõóðàâíåíèå (0.40) äîïóñêàåò ðàçäåëåíèå ïåðåìåííûõ.Ðàññìîòðèì ñëó÷àé, êîãäà ÷èñëîn,çàäàþùåå íåâîçìóùåííîåñîáñòâåííîå çíà÷åíèå, âåëèêî ( äëÿ îïðåäåëåííîñòè áóäåì ñ÷èòàòü,÷òîλèìååò ïîðÿäîêε−1 )[68].  2 äëÿ êàæäîãîk = 0, 1, 2, . . .áóäåò íàéäåíî àñèìïòîòè÷åñêîå ñîáñòâåííîå çíà÷åíèå (0.43), ëåæàùåå âáëèçè âåðõíèõ ãðàíèö ñïåêòðàëüíûõ êëàñòåðîâ. Çäåñü ÷èñëîδ0 = 1/4,à ïðèk ≥ 1÷èñëàδkçàäàþòñÿ ôîðìóëîé (0.44). Ñîîò-âåòñòâóþùèå àñèìïòîòè÷åñêèå ñîáñòâåííûå ôóíêöèè ëîêàëèçîâàíûâáëèçè îêðóæíîñòåé.Ïðîèçâåäåì ñðàâíåíèå ôîðìóëû (0.43) ñ ôîðìóëàìè äëÿ àñèìïòîòèêè ñïåêòðà äâóìåðíîãî îïåðàòîðà òèïà Õàðòðè â ñëó÷àå ãëàäêîãî ÿäðà ñàìîäåéñòâèÿ. Ðàíåå â 1 è 2 âòîðîé ãëàâû áûëà ðàññìîòðåíà çàäà÷à íà ñîáñòâåííûå çíà÷åíèÿ â(H0 +ε2ZL2 (R2 )W (|x−x0 |2 ) | v(x0 ) |2 dx0 )v = Ev,kvkL2 (R2 ) = 1,R2ãäåε2H0 = −2∂2∂2+∂x21 ∂x22x21 + x22+,2(3.94)266ε>0 ìàëûå ïàðàìåòð, àW (τ ) = w0 + w1 τ + w2 τ 2 ïðîèçâîëü-íûé ìíîãî÷ëåí âòîðîé ñòåïåíè ñ âåùåñòâåííûìè êîýôôèöèåíòàìè,ó êîòîðîãîw 2 > 0.Àñèìïòîòè÷åñêèå ñîáñòâåííûå çíà÷åíèÿ çàäà÷è(3.94) âáëèçè âåðõíèõ ãðàíèö ñïåêòðàëüíûõ êëàñòåðîâ èìåþò âèäE = En,k = nε + ε + (w0 + 2nεw1 + 9n2 ε2 w2 )ε2 +√+(2w1 +2nεw2 (9−2 6(k+1/2)))ε3 +O(ε4 ),k = 0, 1, 2, .
. . ,ε → 0.(3.95)n ∈ N èìååò ïîðÿäîê ε−1 è îïðåäåëÿåò ñîáñòâåííîå çíà÷åíèå ε(n+1) íåâîçìóùåííîãî îïåðàòîðà H0 . Àíàëîãè÷íàÿ ôîðìóëàÇäåñü ÷èñëîñïðàâåäëèâà è âáëèçè íèæíèõ ãðàíèö ñïåêòðàëüíûõ êëàñòåðîâ:E = En,k = nε + ε + (w0 + 2nεw1 + 6n2 ε2 w2 )ε2 ++(2w1 + 2nεw2 (2k + 7)))ε3 + O(ε4 ),k = 0, 1, 2, . . . ,ε → 0.(3.96)Ïðîèçâåäåì çàìåíó ïåðåìåííûõx=√εq,√v = ψ/ ε,ε2E = λε − ln ε.2(3.97)Òîãäà çàäà÷à (0.40), (0.41) ïðèíèìàåò âèä (3.94), â êîòîðîìW (τ ) = −ln τ.2(3.98)Ñîîòâåòñòâåííî, ôîðìóëó (0.43) ìîæíî ïåðåïèñàòü â âèäåE = En,k2ε5/2 δkε2= nε+ε− ln(nε)− √+O(ε3 ), k = 0, 1, 2, . .
. , ε → 0.2πnε(3.99)Ñðàâíèâàÿ (3.99) ñ (3.95) è (3.96), âèäèì, ÷òî ðàñùåïëåíèå ñïåêòðà â(3.99) ïðîèñõîäèò â ÷ëåíå ïîðÿäêàïîïðàâêè îò ÷èñëàkε5/2 ,à íåε3 ,ïðè÷åì çàâèñèìîñòüâ ñëó÷àå íåãëàäêîãî ïîòåíöèàëà ñàìîäåéñòâèÿñòàíîâèòñÿ íåëèíåéíîé.2672.2.Ïîñòðîåíèå àñèìïòîòè÷åñêîãî ðåøåíèÿq1 = ρ cos ϕ, q2 = ρ sin ϕ è±imϕ(0.41) â âèäå ψ = g(ρ, ε)e,Ïåðåéäåì ê ïîëÿðíûì êîîðäèíàòàìáóäåì èñêàòü ðåøåíèå çàäà÷è (0.40),ãäåZm = 0, 1, 2, . . . .Ó÷èòûâàÿ, ÷òî[79](π20 2000ln(ρ + (ρ ) − 2ρρ cos(ϕ − ϕ))dϕ =−πïîëó÷àåì çàäà÷ó íà ñîáñòâåííûå çíà÷åíèÿ âHρ − 2περZg 2 (ρ0 , ε)ρ0 dρ0 +ln ρL2 (R1+ )∞Z04π ln ρ, 0 < ρ0 < ρ,4π ln ρ0 ,ρ0 > ρ,ln ρ0 g 2 (ρ0 , ε)ρ0 dρ0 −ρ−λ g(ρ, ε) = 0,∞Zg 2 (ρ, ε)ρdρ =0Çäåñü îïåðàòîðHρèìååò âèä1Hρ = −21 ∂∂m2ρ2ρ− 2 + .ρ ∂ρ∂ρρ2g = g(ρ, ε)ñòåïåíÿì εÁóäåì èñêàòüðàçëîæåíèé ïî1.2πg∼∞Xjèε gj (ρ),j=0λ = λ(ε)λ∼∞Xâ âèäå àñèìïòîòè÷åñêèõ(2πε)j λj .(3.100)j=0Äâà ïåðâûå ÷ëåíà ðàçëîæåíèé (3.100) óäîâëåòâîðÿþò ñëåäóþùèìçàäà÷àì:(Hρ − λ0 )g0 = 0,Z0∞g02 (ρ)ρdρ =1;2π(Hρ − λ0 )g1 = F1 (ρ)g0 ,Z ∞g1 (ρ)g0 (ρ)ρdρ = 0,0(3.101)(3.102)(3.103)(3.104)268ãäåF1 (ρ) = 2πρZg02 (ρ0 )ρ0 dρ0ln ρ∞Z+0ln ρ0g02 (ρ0 )ρ0 dρ0+ λ1 .ρÐåøåíèå çàäà÷è (3.101), (3.102) õîðîøî èçâåñòíî ( ñì., íàïðèìåð,[89] ).
Îíî âûðàæàåòñÿ ÷åðåç ïîëèíîìû Ëàãåððàêàæäîãî(n)λ0 = λ0 = n + 1, n = 0, 1, 2, . . .m = n − 2k,ãäå[ ][56]. Äëÿèk = 0, 1, 2, . . . , [n/2],(3.105)îáîçíà÷àåò öåëóþ ÷àñòü ÷èñëà, èìååì:√g0 (ρ) =(n,k)g0 (ρ)=pk!π(n − k)!ρn−2k e−ρ2/2Ln−2k(ρ2 ).kÊàê èçâåñòíî [56], âòîðîå ëèíåéíî íåçàâèñèìðå ðåøåíèåG(ρ) óðàâ-íåíèÿ (3.101) âûðàæàåòñÿ ÷åðåç âûðîæäåííóþ ãèïåðãåîìåòðè÷åñêóþ ôóíêöèþ âòîðîãî ðîäàG(ρ) = ρn−2k eρÈñïîëüçóÿG(ρ)èg0 (ρ),2/2Ψ(a, b, z):Ψ(n − k + 1, n − 2k + 1, −ρ2 ).îáùåå ðåøåíèå íåîäíîðîäíîãî óðàâíåíèÿ(3.103) ìîæíî çàïèñàòü â êâàäðàòóðàõ.
Óñëîâèåì ðàçðåøèìîñòè çàäà÷è (3.103), (3.104) ñëóæèò ðàâåíñòâî∞ZF1 (ρ)g02 (ρ)ρdρ = 0.0ÑïðàâåäëèâàËåììà 3.5.×èñëîλ1 =(n,k)λ1Z= −2π+ρρZg02 (ρ0 )ρ0 dρ0 +[ ln ρ0Z∞0∞ln ρ0 g02 (ρ0 )ρ0 dρ0 ] g02 (ρ)ρdρ,(3.106)269à òàêæå ïðèíàäëåæàùàÿ ïðîñòðàíñòâó L2 (R1+ ) ôóíêöèÿg1 (ρ) =pρZπk!(n − k)!(−1)n−2k+1 [F1 (ρ0 )g0 (ρ0 )G(ρ0 )ρ0 dρ0 g0 (ρ)+0Z∞+F1 (ρ0 )g02 (ρ0 )ρ0 dρ0 G(ρ)] − c1 g0 (ρ),ρãäå êîíñòàíòà∞Zpc1 = 2π 3/2 k!(n − k)!(−1)n−2k+10Z[ρF1 (ρ0 )g0 (ρ0 )G(ρ0 )ρ0 dρ0 ×0∞ZF1 (ρ0 )g02 (ρ0 )ρ0 dρ0 G(ρ)]g0 (ρ)ρdρ,×g0 (ρ) +ρÿâëÿþòñÿ ðåøåíèåì çàäà÷è(3.103), (3.104).Ðàññìîòðèì äàëåå íåáîëüøèå çíà÷åíèÿ ÷èñëàêàçàíî íèæå, èìåííî òàêèå çíà÷åíèÿkk.Êàê áóäåò ïî-îòâå÷àþò âåðõíèì ãðàíèöàìñïåêòðàëüíûõ êëàñòåðîâ.ÑïðàâåäëèâàÒåîðåìà 3.6.Ïðè ε → 0 è n ïîðÿäêà ε−1 ÷èñëî(n,k)λn,k = n + 1 + 2πελ1,k = 0, 1, 2, .
. . ,è ôóíêöèÿψn,k = (g0 (ρ) + εg1 (ρ))e±i(n−2k)ϕ ,k = 0, 1, 2, . . . ,ÿâëÿþòñÿ àñèìïòîòè÷åñêèì ñîáñòâåííûì çíà÷åíèåì è àñèìïòîòè÷åñêîé ñîáñòâåííîé ôóíêöèåé çàäà÷è(0.40), (0.41)â ïðîñòðàí-ñòâå L2 (R2 ). Áîëåå òî÷íî, ïðè λ = λn,k ôóíêöèÿ ψn,k óäîâëåòâîðÿåò óðàâíåíèþ (0.40) ñ òî÷íîñòüþ O n−3 ñ îöåíêîé íåâÿçêè âíîðìå L2 (R2 ), à òàêæå óñëîâèþ íîðìèðîâêèO n−3 .(0.41)ñ òî÷íîñòüþ2702.3.Àñèìïòîòèêà ñîáñòâåííûõ ôóíêöèé âáëèçèîêðóæíîñòè.
Âû÷èñëåíèå ñïåêòðàëüíûõ ïîïðàâîêÏîëüçóÿñü çàìåíîé (3.97), ïðèâåäåì çàäà÷ó (0.40), (0.41) ê ñòàíäàðòíîìó äëÿ òåîðèè êâàçèêëàññè÷åñêèõ ïðèáëèæåíèé âèäó (3.94),â êîòîðîì ÿäðî ñàìîäåéñòâèÿ çàäàåòñÿ ôîðìóëîé (3.98). Íàéäåìàñèìïòîòèêó ñîáñòâåííûõ ôóíêöèé íåâîçìóùåííîé çàäà÷è√vm,k = pπε(m + k)!m = n − 2k , r =| x |,√R2 . Çäåñü a = εm.ãäåâk!r√εme−r2/(2ε)Lmkâáëèçè îêðóæíîñòèr2εe±imϕ ,(3.107)Γa = {(r, ϕ) | r = a}Ââåäåì íîâóþ ïåðåìåííóþ√s=r2m( − 1).a(3.108)ÑïðàâåäëèâàÒåîðåìà 3.7.Ïðè m → ∞ è íåáîëüøèõ k = 0, 1, 2, .