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slide-1
SLIDE 1

❏♦✉r♥é❡s ❞❡ Pr♦❜❛❜✐❧✐tés ✷✵✵✼ ▲❛ ▲♦♥❞❡✱ ✶✵✲✶✹ s❡♣t❡♠❜r❡ ✷✵✵✼

Pr✐♥❝✐♣❡ ❞❡ ▼❛①✐♠✉♠ ❡t ❚❤é♦rè♠❡ ❞❡ ❈♦♠♣❛r✐s♦♥ ♣♦✉r ❧❡s s♦❧✉t✐♦♥s ❞✬❊❉P❙ q✉❛s✐✲❧✐♥é❛✐r❡s ❙P❉❊✬s ❆✳ ▼❛t♦✉ss✐ ✭❯♥✐✈❡rs✐té ❞✉ ▼❛✐♥❡✱ ▲❡ ▼❛♥s✮

✫ ▲✳ ❉❡♥✐s ✭❯♥✐✈❡rs✐té ❞✬❊✈r②✮ ✫ ▲✳ ❙t♦✐❝❛ ✭❯♥✐✈❡rs✐té ❞❡ ❇✉❝❤❛r❡st✱ ❘♦✉♠❛♥✐❡✮ ✵✲✵

slide-2
SLIDE 2

Pr♦❜❧❡♠ ✿

❲❡ st✉❞② t❤❡ ❢♦❧❧♦✇✐♥❣ st♦❝❤❛st✐❝ ♣❛rt✐❛❧ ❞✐✛❡r❡♥t✐❛❧ ❡q✉❛t✐♦♥ ✭✐♥ s❤♦rt ❙P❉❊✮ ❢♦r ❛ r❡❛❧ ✲✈❛❧✉❡❞ r❛♥❞♦♠ ✜❡❧❞ ut (x) := u (t, x) , dut (x) = Lut (x) dt + ft (x, ut (x) , ∇ut (x)) dt +

d

  • i=1

∂igi,t (x, ut (x) , ∇ut (x)) dt +

d1

  • j=1

hj,t (x, ut (x) , ∇ut (x)) dBj

t

✭✶✮ ✇✐t❤ ❛ ❣✐✈❡♥ ✐♥✐t✐❛❧ ❝♦♥❞✐t✐♦♥ u0 = ξ, ✇❤❡r❡ L ✐s ❛ s②♠♠❡tr✐❝ s❡❝♦♥❞ ♦r❞❡r ❞✐✛❡r❡♥t✐❛❧ ♦♣❡r❛t♦r ❞❡✜♥❡❞ ✐♥ s♦♠❡ ❜♦✉♥❞❡❞ ♦♣❡♥ ❞♦♠❛✐♥ O ⊂ Rd ❛♥❞ f, gi, i = 1, ..., d, hj, j = 1, ..., d1 ❛r❡ ♥♦♥❧✐♥❡❛r r❛♥❞♦♠ ❢✉♥❝t✐♦♥s✳ ❲❡ st✉❞② ✿ ✲ t❤❡ ♠❛①✐♠✉♠ ♣r✐♥❝✐♣❧❡ ❢♦r t❤❡ ❙P❉❊ (E) ✲ ❝♦♠♣❛r✐s♦♥ t❤❡♦r❡♠✳ ✲ ❡①✐st❡♥❝❡ ❛♥❞ ✉♥✐q✉❡♥❡ss ♦❢ t❤❡ s♦❧✉t✐♦♥ ♦❢ t❤❡ st♦❝❤❛st✐❝ ❇✉r❣❡r ❡q✉❛t✐♦♥✳

✵✲✶

slide-3
SLIDE 3

❚❤❡ ♠❛①✐♠✉♠ ♣r✐♥❝✐♣❧❡ ❢♦r q✉❛s✐❧✐♥❡❛r ♣❛r❛❜♦❧✐❝ ❡q✉❛t✐♦♥s ✭t❤❡ ❞❡t❡r♠✐♥✐st✐❝ ❝❛s❡ ✿ h = 0✮ ✇❛s ♣r♦✈❡❞ ❜② ❆r♦♥s♦♥ ✲❙❡rr✐♥ ✭✶✾✻✼✮ ✐♥ t❤❡ ❢♦❧❧♦✇✐♥❣ ❢♦r♠ ✿ ❚❤❡♦r❡♠ ✿ ▲❡t u ❜❡ ❛ ✇❡❛❦ s♦❧✉t✐♦♥ ♦❢ ❛ q✉❛s✐❧✐♥❡❛r ♣❛r❛❜♦❧✐❝ ❡q✉❛t✐♦♥ ♦❢ t❤❡ ❢♦r♠ ∂tu = divA (t, x, u, ∇u) + B (t, x, u, ∇u) ✐♥ t❤❡ ❜♦✉♥❞❡❞ ❝②❧✐♥❞❡r ]0, T[×O ⊂ Rd+1. ■❢ u ≤ M ♦♥ t❤❡ ♣❛r❛❜♦❧✐❝ ❜♦✉♥❞❛r② {[0, T[×∂O} ∪ {{0} × O}✱ t❤❡♥ ♦♥❡ ❤❛s u ≤ M + Ck (A, B), ✇❤❡r❡ C ❞❡♣❡♥❞s ♦♥❧② ♦♥ T, t❤❡ ✈♦❧✉♠❡ ♦❢ O ❛♥❞ t❤❡ str✉❝t✉r❡ ♦❢ t❤❡ ❡q✉❛t✐♦♥✱ ✇❤✐❧❡ k (A, B) ✐s ❞✐r❡❝t❧② ❡①♣r❡ss❡❞ ✐♥ t❡r♠s ♦❢ s♦♠❡ q✉❛♥t✐t✐❡s r❡❧❛t❡❞ t♦ t❤❡ ❝♦❡✣❝✐❡♥ts A ❛♥❞ B. ❚❤❡ ♠❡t❤♦❞ ♦❢ ♣r♦♦❢ ✇❛s ❜❛s❡❞ ♦♥ ▼♦s❡r✬s ✐t❡r❛t✐♦♥ s❝❤❡♠❡ ❛❞❛♣t❡❞ t♦ t❤❡ ♥♦♥❧✐♥❡❛r ❝❛s❡✳ ❚❤✐s ♠❡t❤♦❞ ✇❛s ❢✉rt❤❡r ❛❞❛♣t❡❞ t♦ t❤❡ st♦❝❤❛st✐❝ ❢r❛♠❡✇♦r❦ ✐♥ ❉❡♥✐s✱ ▼✳ ❛♥❞ ❙t♦✐❝❛ ✭✷✵✵✺✮✱ ♦❜t❛✐♥✐♥❣ s♦♠❡ Lp ❛ ♣r✐♦r✐ ❡st✐♠❛t❡s ❢♦r t❤❡ ✉♥✐❢♦r♠ ♥♦r♠ ♦❢ t❤❡ s♦❧✉t✐♦♥ ♦❢ t❤❡ st♦❝❤❛st✐❝ q✉❛s✐❧✐♥❡❛r ♣❛r❛❜♦❧✐❝ ❡q✉❛t✐♦♥✳

✵✲✷

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SLIDE 4

❲❡ ♣r♦✈❡ t❤❡ st♦❝❤❛st✐❝ ✈❡rs✐♦♥ ♦❢ t❤❡ ♠❛①✐♠✉♠ ♣r✐♥❝✐♣❧❡ ♦❢ ❆r♦♥s♦♥ ✲❙❡rr✐♥ ✿ ❚❤❡♦r❡♠ ✿ ▲❡t p ≥ 2 ❛♥❞ u ❜❡ ❛ s♦❧✉t✐♦♥ ♦❢ ✭✶✮ ✐♥ t❤❡ ✇❡❛❦ s❡♥s❡✳ ❆ss✉♠❡ t❤❛t u ≤ M ♦♥ t❤❡ ♣❛r❛❜♦❧✐❝ ❜♦✉♥❞❛r② {[0, T[×∂O} ∪ {{0} × O}✱ t❤❡♥ ❢♦r ❛❧❧ t ∈ [0, T] ✿ E

  • (u − M)+

p

∞,∞;t ≤ k (p, t) E

  • (ξ − M)+p

∞ +

  • (f 0,M)+

∗p

θ,t +

  • |g0,M|2

∗p/2

θ;t

+

  • |h0,M|2

∗p/2

θ;t

  • ✇❤❡r❡ ✿

f 0,M(t, x) = f(t, x, M, 0), g0,M(t, x) = g(t, x, M, 0), h0,M(t, x) = h(t, x, M, 0) ❛♥❞ k ✐s ❛ ❢✉♥❝t✐♦♥ ✇❤✐❝❤ ♦♥❧② ❞❡♣❡♥❞s ♦♥ t❤❡ str✉❝t✉r❡ ❝♦♥st❛♥ts ♦❢ t❤❡ ❙P❉❊✱ ·∞,∞;t ✐s t❤❡ ✉♥✐❢♦r♠ ♥♦r♠ ♦♥ [0, t]×O ❛♥❞ ·∗

θ;t ✐s ❛ ❝❡rt❛✐♥ ♥♦r♠ ✇❤✐❝❤ ✐s ♣r❡❝✐s❡❧② ❞❡✜♥❡❞

❜❡❧♦✇✳

✵✲✸

slide-5
SLIDE 5

❍②♣♦t❤❡s✐s ❛♥❞ ❞❡✜♥✐t✐♦♥s ✿ ⋄ O ⊂ Rd ♦♣❡♥ ❜♦✉♥❞❡❞ s❡t✳ ⋄ (Bt)t d1✲❞✐♠❡♥s✐♦♥❛❧ ❇▼ ❞❡✜♥❡❞ ♦♥ (Ω, F, (Ft)t, P)✱ ⋄ A := −L := − ∂i(ai,j∂j) ✿ s②♠♠❡tr✐❝ s❡❝♦♥❞ ♦r❞❡r ❞✐✛❡r❡♥t✐❛❧ ♦♣❡r❛t♦r✱ ⋄ a := (aij)i,j ✐s ❛ ♠❡❛s✉r❛❜❧❡ ❛♥❞ s②♠♠❡tr✐❝ ♠❛tr✐① ❛♥❞ s❛t✐s✜❡s ✉♥✐❢♦r♠ ❡❧❧✐♣t✐❝✐t② ✿ λ|ζ|2 ≤

d

  • i,j=1

ai,j(x)ζi ζj ≤ Λ|ζ|2, ∀x ∈ O, ζ ∈ Rd ✇❤❡r❡ λ ❛♥❞ Λ ❛r❡ ♣♦s✐t✐✈❡ ❝♦♥st❛♥ts✳ ⋄ ξ ∈ L2(Ω × O)✳ ⋄ T > 0✳

✵✲✹

slide-6
SLIDE 6

❲❡ ❛r❡ ❣✐✈❡♥ ♣r❡❞✐❝t❛❜❧❡ ❢✉♥❝t✐♦♥s ✿ f : R+ × Ω × O × R × Rd → R , h : R+ × Ω × O × R × Rd → Rd1 g = (¯ g1, ..., ¯ gd) : R+ × Ω × O × R × Rd → Rd. s✉❝❤ t❤❛t ✿ ✶✳ |f(t, ω, x, y, z) − f(t, ω, x, y′, z′)| ≤ C(|y − y′| + |z − z′|) ✷✳ d1

j=1 |hj(t, ω, x, y, z) − hj(t, ω, x, y′, z′)|2 1

2 ≤ C |y − y′| + β |z − z′|✱

✸✳ d

i=1 |gi(t, ω, x, y, z) − gi(t, ω, x, y′, z′)|2 1

2 ≤ C|y − y′| + α |z − z′|✱

✇❤❡r❡ C, α, β ❛r❡ ♥♦♥ ♥❡❣❛t✐✈❡ ❝♦♥st❛♥ts✳ ❈♦♥tr❛❝t✐♦♥ ❤②♣♦t❤❡s✐s ✿ α + 1 2β2 < λ.

✵✲✺

slide-7
SLIDE 7

❲❡❛❦ s♦❧✉t✐♦♥s ♦❢ ❙P❉❊✬s ✿

  • H0 ✿ s❡t ♦❢ H1

0(O)✲✈❛❧✉❡❞ ♣r❡❞✐❝t❛❜❧❡ ♣r♦❝❡ss❡s u s✳t✳

uE,T :=

  • E sup

0≤t≤T

ut2 + T E E (ut, ut) dt 1/2 < ∞ . ✇❤❡r❡ E ✐s t❤❡ ❡♥❡r❣② ✭❉✐r✐❝❤❧❡t ❢♦r♠ ❛ss♦❝✐❛t❡❞ t♦ t❤❡ ❧✐♥❡❛r ♦♣❡r❛t♦r A✮ ✿ E(u, v) :=

  • O

d

  • i,j=1

ai,j∂iu ∂jv dx, ∀u ∈ H1

loc(O), ∀v ∈ H1 0(O).

  • Hloc ✿ s❡t ♦❢ H1

loc(O)✲✈❛❧✉❡❞ ♣r❡❞✐❝t❛❜❧❡ ♣r♦❝❡ss❡s s✉❝❤ t❤❛t ❢♦r ❛♥② ❝♦♠♣❛❝t s✉❜s❡t K ✐♥ O ✿

uE,K,T :=

  • E sup

0≤t≤T

  • K

ut(x)2 dx + E T

  • K

|∇ut(x)|2 dxdt 1/2 < ∞ .

✵✲✻

slide-8
SLIDE 8

❉❡✜♥✐t✐♦♥ ✿ u ∈ Hloc ✐s ❛ ✇❡❛❦ s♦❧✉t✐♦♥ ♦❢ (E)✱ ✇✐t❤ ✐♥✐t✐❛❧ ❝♦♥❞✐t✐♦♥ u0 = ξ✱ ✐❢ ❢♦r ❡❛❝❤ t❡st ❢✉♥❝t✐♦♥ ϕ ∈ D := C∞

c ([0, T)) ⊗ C2 c (O).

T [(us, ∂sϕ) − E (us, ϕs) +(f (s, us, ∇us) , ϕs) − (gi (s, us, ∇us) , ∂iϕs)]ds + T (hj (us, ∇us) , ϕs) dBj

s + (ξ, ϕ0) = 0.

✇❤❡r❡ ( , ) ✐s t❤❡ ✐♥♥❡r ♣r♦❞✉❝t ✐♥ L2(O)✳ ❲❡ ❞❡♥♦t❡ ❜② Uloc(ξ, f, g, h) t❤❡ s❡t ♦❢ s✉❝❤ s♦❧✉t✐♦♥✳ ■❢ u ∈ H0 ✐s ❛ ✇❡❛❦ s♦❧✉t✐♦♥✱ ✇❡ s❛② t❤❛t ✐t s♦❧✈❡s (E) ✇✐t❤ ③❡r♦ ❉✐r✐❝❤❧❡t ❝♦♥❞✐t✐♦♥ ♦♥ ∂O ❛♥❞ ✇❡ ❞❡♥♦t❡ u = U0(ξ, f, g, h) ✳

✵✲✼

slide-9
SLIDE 9

❋✉♥❝t✐♦♥❛❧ s♣❛❝❡s ✿

  • ❲❡ s❤❛❧❧ ✉s❡ t❤❡ ♥♦t❛t✐♦♥

(u, v) =

  • O

u(x)v(x) dx, ✇❤❡r❡ u✱ v ❛r❡ ♠❡❛s✉r❛❜❧❡ ❢✉♥❝t✐♦♥s ❞❡✜♥❡❞ ✐♥ O ❛♥❞ uv ∈ L1(O)✳

  • H1

0 (O) t❤❡ ❍✐❧❜❡rt s♣❛❝❡ ✿ t❤❡ ✜rst ♦r❞❡r ❙♦❜♦❧❡✈ s♣❛❝❡ ♦❢ ❢✉♥❝t✐♦♥s ✈❛♥✐s❤✐♥❣ ❛t t❤❡ ❜♦✉♥❞❛r②✱

■ts ♥❛t✉r❛❧ s❝❛❧❛r ♣r♦❞✉❝t ❛♥❞ ♥♦r♠ ❛r❡ (u, v)H1

0(O) = (u, v) +

  • O

d

  • i=1

(∂iu (x)) (∂iv (x)) dx, uH1

0(O) =

  • u2

2 + ∇u2 2

1

2 .

  • H1

loc(O) t❤❡ s♣❛❝❡ ♦❢ ❢✉♥❝t✐♦♥s ✇❤✐❝❤ ❛r❡ ❧♦❝❛❧❧② sq✉❛r❡ ✐♥t❡❣r❛❜❧❡ ✐♥ O ❛♥❞ ✇❤✐❝❤ ❛❞♠✐t ✜rst

♦r❞❡r ❞❡r✐✈❛t✐✈❡s t❤❛t ❛r❡ ❛❧s♦ ❧♦❝❛❧❧② sq✉❛r❡ ✐♥t❡❣r❛❜❧❡✳

  • ❋♦r ❡❛❝❤ t > 0 ❛♥❞ ❢♦r ❛❧❧ r❡❛❧ ♥✉♠❜❡rs p, q ≥ 1✱ ✇❡ ❞❡♥♦t❡ ❜② Lp,q([0, t] × O) t❤❡ s♣❛❝❡ ♦❢

✭❝❧❛ss❡s ♦❢✮ ♠❡❛s✉r❛❜❧❡ ❢✉♥❝t✐♦♥s u : [0, t] × O − → R s✉❝❤ t❤❛t up,q; t := t

  • O

|u(t, x)|p dx q/p dt 1/q ✐s ✜♥✐t❡✳ ❚❤❡ ❧✐♠✐t✐♥❣ ❝❛s❡s ✇✐t❤ p ♦r q t❛❦✐♥❣ t❤❡ ✈❛❧✉❡ ∞ ❛r❡ ❛❧s♦ ❝♦♥s✐❞❡r❡❞ ✇✐t❤ t❤❡ ✉s❡ ♦❢ t❤❡

✵✲✽

slide-10
SLIDE 10

❡ss❡♥t✐❛❧ s✉♣ ♥♦r♠✳ ❲❡ ✐❞❡♥t✐❢② t❤✐s s♣❛❝❡✱ ✐♥ ❛♥ ♦❜✈✐♦✉s ✇❛②✱ ✇✐t❤ t❤❡ s♣❛❝❡ Lq ([0, t] ; Lp (O)) , ❝♦♥s✐st✐♥❣ ♦❢ ❛❧❧ ♠❡❛s✉r❛❜❧❡ ❢✉♥❝t✐♦♥s u : [0, t] → Lp (O) s✉❝❤ t❤❛t t usq

p ds < ∞. ❚❤✐s

✐❞❡♥t✐✜❝❛t✐♦♥ ✐♠♣❧✐❡s t❤❛t t usq

p ds

1

q

= up,q; t.

  • ❚❤❡ s♣❛❝❡ ♦❢ ♠❡❛s✉r❛❜❧❡ ❢✉♥❝t✐♦♥s u : R+ → L2 (O) s✉❝❤ t❤❛t u2,2;t < ∞, ❢♦r ❡❛❝❤ t ≥ 0, ✐s

❞❡♥♦t❡❞ ❜② L2

loc (R+; L2 (O)) .

  • ❙✐♠✐❧❛r❧②✱ t❤❡ s♣❛❝❡ L2

loc (R+; H1 0 (O)) ❝♦♥s✐sts ♦❢ ❛❧❧ ♠❡❛s✉r❛❜❧❡ ❢✉♥❝t✐♦♥s u : R+ → H1 0 (O)

s✉❝❤ t❤❛t u2,2;t + ∇u2,2;t < ∞, ❢♦r ❛♥② t ≥ 0.

  • ◆❡①t ✇❡ ❛r❡ ❣♦✐♥❣ t♦ ✐♥tr♦❞✉❝❡ s♦♠❡ ♦t❤❡r s♣❛❝❡s ♦❢ ❢✉♥❝t✐♦♥s ♦❢ ✐♥t❡r❡st ✇❤✐❝❤ ❤❛✈❡ ❛❧r❡❛❞②

❜❡❡♥ ✉s❡❞ ✐♥ ❆r♦♥s♦♥ ❛♥❞ ❙❡rr✐♥ ✿ ▲❡t (p1, q1) , (p2, q2) ∈ [1, ∞]2 ❜❡ ✜①❡❞ ❛♥❞ s❡t I = I (p1, q1, p2, q2) :=

  • (p, q) ∈ [1, ∞]2 / ∃ ρ ∈ [0, 1] s.t. 1

p = ρ 1 p1 + (1 − ρ) 1 p2 , 1 q = ρ 1 q1 + (1 − ρ) 1 q2

  • .

✵✲✾

slide-11
SLIDE 11

❚❤✐s ♠❡❛♥s t❤❛t t❤❡ s❡t ♦❢ ✐♥✈❡rs❡ ♣❛✐rs

  • 1

p, 1 q

  • , (p, q) ❜❡❧♦♥❣✐♥❣ t♦ I, ✐s ❛ s❡❣♠❡♥t ❝♦♥t❛✐♥❡❞ ✐♥

t❤❡ sq✉❛r❡ [0, 1]2 , ✇✐t❤ t❤❡ ❡①tr❡♠✐t✐❡s

  • 1

p1, 1 q1

  • ❛♥❞
  • 1

p2, 1 q2

  • .
  • ❚❤❡r❡ ❛r❡ t✇♦ s♣❛❝❡s ♦❢ ✐♥t❡r❡st ❛ss♦❝✐❛t❡❞ t♦ I. ❖♥❡ ✐s t❤❡ ✐♥t❡rs❡❝t✐♦♥ s♣❛❝❡

LI;t =

  • (p,q)∈I

Lp,q ([0, t] × O) . ❍ö❧❞❡r✬s ✐♥❡q✉❛❧✐t② ❧❡❛❞ t♦ t❤❡ ❢♦❧❧♦✇✐♥❣ ✐♥❝❧✉s✐♦♥ ✿ Lp1,q1 ([0, t] × O) ∩ Lp2,q2 ([0, t] × O) ⊂ Lp,q ([0, t] × O) , ❢♦r ❡❛❝❤ (p, q) ∈ I, ❛♥❞ t❤❡ ✐♥❡q✉❛❧✐t② up,q;t ≤ up1,q1;t ∨ up2,q2;t ❢♦r ❛♥② u ∈ Lp1,q1 ([0, t] × O) ∩ Lp2,q2 ([0, t] × O) .

  • ▼♦r❡♦✈❡r✱ ❜② ❍ö❧❞❡r✬s ✐♥❡q✉❛❧✐t②✱ ✐t ❢♦❧❧♦✇s t❤❛t ♦♥❡ ❤❛s

t

  • O

u (s, x) v (s, x) dxds ≤ uI;t vI′;t , ✭✷✮ ❢♦r ❛♥② u ∈ LI;t ❛♥❞ v ∈ LI′;t. ❚❤✐s ✐♥❡q✉❛❧✐t② s❤♦✇s t❤❛t t❤❡ s❝❛❧❛r ♣r♦❞✉❝t ♦❢ L2 ([0, t] × O) ❡①t❡♥❞s t♦ ❛ ❞✉❛❧✐t② r❡❧❛t✐♦♥ ❢♦r t❤❡ s♣❛❝❡s LI;t ❛♥❞ LI′;t.

✵✲✶✵

slide-12
SLIDE 12
  • ◆♦✇ ❧❡t ✉s r❡❝❛❧❧ t❤❛t t❤❡ ❙♦❜♦❧❡✈ ✐♥❡q✉❛❧✐t② st❛t❡s t❤❛t

u2∗ ≤ cS ∇u2, ❢♦r ❡❛❝❤ u ∈ H1

0 (O) , ✇❤❡r❡ cS > 0 ✐s ❛ ❝♦♥st❛♥t t❤❛t ❞❡♣❡♥❞s ♦♥ t❤❡ ❞✐♠❡♥s✐♦♥ ❛♥❞ 2∗ = 2d d−2

✐❢ d > 2, ✇❤✐❧❡ 2∗ ♠❛② ❜❡ ❛♥② ♥✉♠❜❡r ✐♥ ]2, ∞[ ✐❢ d = 2 ❛♥❞ 2∗ = ∞ ✐❢ d = 1.

  • ❚❤❡r❡❢♦r❡ ♦♥❡ ❤❛s

u2∗,2;t ≤ cS ∇u2,2;t , ❢♦r ❡❛❝❤ t ≥ 0 ❛♥❞ ❡❛❝❤ u ∈ L2

loc (R+; H1 0 (O)) .

✵✲✶✶

slide-13
SLIDE 13
  • ✐❢ u ∈ L∞

loc (R+; L2 (O) ) L2 loc (R+; H1 0 (O)) , ♦♥❡ ❤❛s

u2,∞;t ∨ u2∗,2;t ≤ c1

  • u2

2,∞;t + ∇u2 2,2;t

1

2 ,

✇✐t❤ c1 = cS ∨ 1.

  • ❖♥❡ ♣❛rt✐❝✉❧❛r ❝❛s❡ ♦❢ ✐♥t❡r❡st ❢♦r ✉s ✐♥ r❡❧❛t✐♦♥ ✇✐t❤ t❤✐s ✐♥❡q✉❛❧✐t② ✐s ✇❤❡♥ p1 = 2, q1 = ∞

❛♥❞ p2 = 2∗, q2 = 2. ■❢ I = I (2, ∞, 2∗, 2) , t❤❡♥ t❤❡ ❝♦rr❡s♣♦♥❞✐♥❣ s❡t ♦❢ ❛ss♦❝✐❛t❡❞ ❝♦♥❥✉❣❛t❡ ♥✉♠❜❡rs ✐s I′ = I′ (2, ∞, 2∗, 2) = I

  • 2, 1,

2∗ 2∗−1, 2

  • , ✇❤❡r❡ ❢♦r d = 1 ✇❡ ♠❛❦❡ t❤❡ ❝♦♥✈❡♥t✐♦♥ t❤❛t

2∗ 2∗−1 = 1.

  • ■♥ t❤✐s ♣❛rt✐❝✉❧❛r ❝❛s❡ ✇❡ s❤❛❧❧ ✉s❡ t❤❡ ♥♦t❛t✐♦♥ L#;t := LI;t ❛♥❞ L∗

#;t := LI′;t ❛♥❞ t❤❡ r❡s♣❡❝t✐✈❡

♥♦r♠s ✇✐❧❧ ❜❡ ❞❡♥♦t❡❞ ❜② u#;t := uI;t = u2,∞;t ∨ u2∗,2;t , u∗

#;t := uI′;t .

❚❤✉s ✇❡ ♠❛② ✇r✐t❡ u#;t ≤ c1

  • u2

2,∞;t + ∇u2 2,2;t

1

2 ,

✭✸✮ ❢♦r ❛♥② u ∈ L∞

loc (R+; L2 (O) ) L2 loc (R+; H1 0 (O)) ❛♥❞ t ≥ 0 ❛♥❞ t❤❡ ❞✉❛❧✐t② ✐♥❡q✉❛❧✐t② ❜❡❝♦♠❡s

t

  • O

u (s, x) v (s, x) dxds ≤ u#;t v∗

#;t ,

❢♦r ❛♥② u ∈ L#;t ❛♥❞ v ∈ L∗

#;t.

✵✲✶✷

slide-14
SLIDE 14

❍②♣♦t❤❡s❡s ♦♥ ✐♥✐t✐❛❧ ❝♦♥❞✐t✐♦♥s ✿

❋♦r ❛ ❝❡rt❛✐♥ p ≥ 2 ✿

  • ξ ∈ Lp(Ω; L∞(O))✳
  • ❚❤❡r❡ ❡①✐sts θ ∈ (0, 1) s✉❝❤ t❤❛t f 0∗

θ;T✱

  • |g0|2∗

θ;T

1/2 ✱

  • |h0|2∗

θ;T

1/2 ❛r❡ ✐♥ Lp (Ω, P) ✳ ⋄ f 0 := f(., ., ., 0, 0) ∈ L2([0, T] × Ω × O) ✭r❡s♣✳ g0 ❛♥❞ h0✮✳

  • ❆ss✉♠♣t✐♦♥ ✭❍❉✮ ❧♦❝❛❧ ✐♥t❡❣r❛❜✐❧✐t② ❝♦♥❞✐t✐♦♥s ♦♥ f 0✱ g0 ❛♥❞ h0 ✿

E t

  • K

(|f 0

t (x)| + |g0 t (x)|2 + |h0 t|2 )dxdt < ∞

❢♦r ❛♥② ❝♦♠♣❛❝t s❡t K ⊂ O✱ ❛♥❞ ❢♦r ❛♥② t ≥ 0✳

  • ❆ss✉♠♣t✐♦♥ ✭❍■✮ ❧♦❝❛❧ ✐♥t❡❣r❛❜✐❧✐t② ❝♦♥❞✐t✐♦♥ ♦♥ t❤❡ ✐♥✐t✐❛❧ ❝♦♥❞✐t✐♦♥ ✿

E

  • K

|ξ(x)|2dx < ∞ ❢♦r ❛♥② ❝♦♠♣❛❝t s❡t K ⊂ O✳

✵✲✶✸

slide-15
SLIDE 15
  • ❆ss✉♠♣t✐♦♥ ✭❍❉★✮

E

  • f 0

#;t

2 +

  • g0

2

2,2;t +

  • h0

2

2,2;t

  • < ∞,

❢♦r ❡❛❝❤ t ≥ 0. ❙♦♠❡t✐♠❡s ✇❡ s❤❛❧❧ ❝♦♥s✐❞❡r t❤❡ ❢♦❧❧♦✇✐♥❣ str♦♥❣❡r ❢♦r♠s ♦❢ t❤❡s❡ ❝♦♥❞✐t✐♦♥s ✿

  • ❆ss✉♠♣t✐♦♥ ✭❍❉✷✮

E

  • f 0

2

2,2;t +

  • g0

2

2,2;t +

  • h0

2

2,2;t

  • < ∞,

❢♦r ❡❛❝❤ t ≥ 0.

  • ❆ss✉♠♣t✐♦♥ ✭❍■✷✮ ✐♥t❡❣r❛❜✐❧✐t② ❝♦♥❞✐t✐♦♥ ♦♥ t❤❡ ✐♥✐t✐❛❧ ❝♦♥❞✐t✐♦♥ ✿

Eξ2 < ∞.

✵✲✶✹

slide-16
SLIDE 16

■✳ ❙♦❧✉t✐♦♥ ♦❢ (E) ✇✐t❤ ❩❡r♦ ❉✐r✐❝❤❧❡t ❝♦♥❞✐t✐♦♥

  • ▲✳ ❉❡♥✐s✱ ❆✳ ▼✳ ❛♥❞ ▲✳ ❙t♦✐❝❛ ✿ Lp ❡st✐♠❛t❡s ❢♦r t❤❡ ✉♥✐❢♦r♠ ♥♦r♠ ♦❢ s♦❧✉t✐♦♥s ♦❢ q✉❛s✐❧✐♥❡❛r

❙P❉❊✬s✳ Pr♦❜✳ ❚❤❡♦r✳ ❘❡❧❛t❡❞ ❋✐❡❧❞s ✭✷✵✵✺✮✳ ❚❤❡♦r❡♠ ✶ ❊q✉❛t✐♦♥ (E) ❛❞♠✐ts ❛ ✉♥✐q✉❡ s♦❧✉t✐♦♥✱ u ✐♥ H0✳ ❚❤✐s s♦❧✉t✐♦♥ ❤❛s L2(O)✲❝♦♥t✐♥✉♦✉s tr❛❥❡❝t♦r✐❡s ❛♥❞ ✐t s❛t✐s✜❡s t❤❡ ❢♦❧❧♦✇✐♥❣ ❡st✐♠❛t❡ ∀t ∈ [0, T] ✿ E up

∞,∞;t ≤ k (p, t) E

  • ξp

∞ +

  • f 0

∗p

θ,t +

  • |g0|2

∗p/2

θ;t

+

  • |h0|2

∗p/2

θ;t

  • ,

✇❤❡r❡ k ✐s ❛ ❢✉♥❝t✐♦♥ ✇❤✐❝❤ ♦♥❧② ❞❡♣❡♥❞s ♦♥ C, α ❛♥❞ β✳

✵✲✶✺

slide-17
SLIDE 17

▼❛✐♥ t♦♦❧s ❢♦r t❤❡ ♣r♦♦❢ ✿

  • ■t♦✬s ❢♦r♠✉❧❛

▲❡♠♠❛ ✷ ✿ ▲❡t ϕ : R − → R ❜❡ C2 ✇✐t❤ ❜♦✉♥❞❡❞ ❞❡r✐✈❛t✐✈❡s✳ ❚❤❡♥ ❛✳s✳✱ ❢♦r ❛❧❧ t ≥ 0

  • O

ϕ(ut(x)) dx + t E(ϕ′(us), us) ds =

  • O

ϕ(ξ) dx + t (ϕ′(us), fs) ds −

d

  • i=1

t

  • O

ϕ′′(us(x))∂ius(x) gi(s, x) dx ds +

d1

  • j=1

t (ϕ′(us), hj(s)) dBj

s

+1 2

d1

  • j=1

t

  • O

ϕ′′(us(x))h2

j(s, x) dx ds .

✵✲✶✻

slide-18
SLIDE 18
  • ❆s ❛ ❝♦♥s❡q✉❡♥❝❡ ✭ ✦✮

▲❡♠♠❛ ✸ ❋♦r ❛❧❧ l ≥ 2✱ P✲❛❧♠♦st s✉r❡❧②✱ ❢♦r ❛❧❧ t ≥ 0

  • O

|ut(x)|l dx + t E (l (us)l−1 sgn(us), us) ds =

  • O

|ξ(x)|l dx + l t

  • O

sgn(us)|us(x)|l−1f(s, x, us, ∇us) dxds − l(l − 1)

d

  • i=1

t

  • O

|us(x)|l−2∂ius(x) gi(s, x, us, ∇us) dx ds + l

d1

  • j=1

t

  • O

sgn(us)|ut(x)|l−1hj(s, x, us, ∇us) dxdBj

s

+ l(l − 1) 2

d1

  • j=1

t

  • O

|ut(x)|l−2h2

j(s, x, us, ∇us) dx ds .

✇❤❡r❡ E (l (us)l−1 sgn(us), us) = l(l − 1)

d

  • i,j=1
  • O

|us(x)|l−2aij(x) ∂ius(x) ∂jus(x) dx.

✵✲✶✼

slide-19
SLIDE 19
  • ❙♦❜♦❧❡✈✬s ✐♥❡q✉❛❧✐t②✳
  • ❊st✐♠❛t❡s ♦❢ t❤❡ st♦❝❤❛st✐❝ ♣❛rt t❤❛♥❦s t♦ t❤❡ t❤❡♦r② ♦❢ ❞♦♠✐♥❛t✐♦♥ ♦❢ ♣r♦❝❡ss❡s✳
  • ❆r♦♥s♦♥✲❙❡rr✐♥✬s ■t❡r❛t✐♦♥ ✭♦r ▼♦s❡r✬s s❝❤❡♠❡✮

✵✲✶✽

slide-20
SLIDE 20

❆ ❝♦♠♣❛r✐s♦♥ ❚❤❡♦r❡♠ ✿

❲❡ ❦❡❡♣ s❛♠❡ ❤②♣♦t❤❡s❡s✳ ❲❡ ❛r❡ ❣✐✈❡♥ ❛♥♦t❤❡r ❢✉♥❝t✐♦♥ ξ′ ∈ Lp(Ω, L∞(O)) ❛♥❞ ❛♥♦t❤❡r ❝♦❡✣❝✐❡♥t ¯ f ✇❤✐❝❤ s❛t✐s❢② t❤❡ s❛♠❡ ❛ss✉♠♣t✐♦♥s ❛s f✳ ❲❡ st✐❧❧ ❝♦♥s✐❞❡r u = U0(ξ, f, g, h) ❛♥❞ ✇❡ s❡t v = U0(ξ′, ¯ f, g, h)✳ ❚❤❡♦r❡♠ ✹ ❆ss✉♠❡ ξ ≥ ξ′ dP ⊗ dx✲❛✳❡✳ ❛♥❞ f(t, w, x, ut(x), ∇ut(x)) ≥ ¯ f(t, w, x, ut(x), ∇ut(x)), dt ⊗ dP ⊗ dx❛✳❡ ❚❤❡♥✱ ❢♦r ❛❧❧ t ∈ [0, T]✱ ut ≥ vt; dP ⊗ dx − a.e. ■❞❡❛ ♦❢ t❤❡ ♣r♦♦❢ ✿ ❆♣♣❧② ■t♦✬s ❢♦r♠✉❧❛ t♦ |(ut − vt)+|2 ❛♥❞ ●r♦♥✇❛❧❧✬s ▲❡♠♠❛✳

✵✲✶✾

slide-21
SLIDE 21

■■✳ ▲♦❝❛❧ ❙♦❧✉t✐♦♥ ♦❢ (E) ✇✐t❤ ♥♦♥ ❩❡r♦ ❇♦✉♥❞❛r② ❝♦♥❞✐t✐♦♥

  • ▲✳ ❉❡♥✐s✱ ❆✳ ▼✳ ❛♥❞ ▲✳ ❙t♦✐❝❛ ✿ ▼❛①✐♠✉♠ ♣r✐♥❝✐♣❧❡ ❛♥❞ ❈♦♠♣❛r✐s♦♥ ❚❤❡♦r❡♠ ❢♦r ◗✉❛s✐❧✐♥❡❛r

❙P❉❊✬s✳ Pr❡♣r✐♥t ✭✷✵✵✼✮✱ s✉❜♠✐tt❡❞✳

  • ❲❡ ❝♦♥s✐❞❡r t❤❡ ♣❛r❛❜♦❧✐❝ ❜♦✉♥❞❛r② ✿ Γ = {∂O × [0, T]} {O × (t = 0)}✳
  • M✱ ❛♥ R✲✈❛❧✉❡❞ ♣r♦❝❡ss ❣✐✈❡♥ ❜②

∀t ≥ 0, Mt = m + t bs ds + t σs dBs, ✇❤❡r❡ b ✱ σ ❛r❡ ♣r❡❞✐❝t❛❜❧❡ ♣r♦❝❡ss❡s s✉❝❤ t❤❛t ✿ E T |bs|

1 1−θ ds

p < +∞ ❛♥❞ E T |σs|

2 1−θ ds

p < +∞. ■♥ ♣❛rt✐❝✉❧❛r✱ t❤❡s❡ ❝♦♥❞✐t✐♦♥s ✐♠♣❧② t❤❛t E(M∗p

θ,T) < +∞✳

  • ▲❡t ✉s ♥♦✇ ♣r❡❝✐s❡ t❤❡ s❡♥s❡ ✐♥ ✇❤✐❝❤ ❛ s♦❧✉t✐♦♥ ✐s ❞♦♠✐♥❛t❡❞ ♦♥ t❤❡ ❧❛t❡r❛❧ ❜♦✉♥❞❛r② ✿ ❆ss✉♠❡

t❤❛t v ❜❡❧♦♥❣s t♦ H1

loc(O′) ✇❤❡r❡ O′ ✐s ❛ ❧❛r❣❡r ♦♣❡♥ s❡t s✉❝❤ t❤❛t O ⊂ O′✳ ❚❤❡♥ t❤❡ ❝♦♥❞✐t✐♦♥

v+

|O ∈ H1 0(O) ❡①♣r❡ss❡s t❤❡ ❜♦✉♥❞❛r② r❡❧❛t✐♦♥ v ≤ 0 ♦♥ ∂O✳

❙✐♠✐❧❛r❧②✱

✵✲✷✵

slide-22
SLIDE 22

❉❡✜♥✐t✐♦♥ ✺ ✐❢ ❛ ♣r♦❝❡ss u ❜❡❧♦♥❣s t♦ Hloc(O′), t❤❡♥ t❤❡ ❝♦♥❞✐t✐♦♥ u+

|O ∈ H0 ❡♥s✉r❡s t❤❡ ✐♥✲

❡q✉❛❧✐t② u ≤ 0 ♦♥ t❤❡ ❧❛t❡r❛❧ ❜♦✉♥❞❛r② {[0, ∞[×∂O}✳ ❚❤❡♦r❡♠ ✻ ▲❡t u ∈ Uloc(ξ, f, g, h)✳ ❆ss✉♠❡ t❤❛t u ≤ M ♦♥ Γ✱ t❤❡♥ ❢♦r ❛❧❧ t ∈ [0, T] ✿ E

  • (u − M)+

p

∞,∞;t ≤ k (t) E

  • (ξ − M)p

∞ +

  • (f M − b)+

∗p

θ,t +

  • |gM|2

∗p/2

θ;t

+

  • |(hM − σ)|2

∗p/2

θ;t

  • ✇❤❡r❡ f M(t, x) = f(t, x, Mt, 0) ✱ gM(t, x) = g(t, x, Mt, 0)✱ hM(t, x) = h(t, x, Mt, 0)✳

❘❡♠❛r❦ ✶ ■❢ M ✐s ❛ ❝♦♥st❛♥t✱ t❤❡♥ ✉s✐♥❣ t❤❡ ▲✐♣s❝❤✐t③ ❝♦♥❞✐t✐♦♥ ♦♥ t❤❡ ❝♦❡✣❝✐❡♥ts✱ ✇❡ ❣❡t ❛♥ ❡st✐♠❛t❡ s✐♠✐❧❛r t♦ t❤❡ ❝❧❛ss✐❝❛❧ ♦♥❡ ❢♦r q✉❛s✐❧✐♥❡❛r P❉❊ ♦❜t❛✐♥❡❞ ❜❛② ❆rr♦♥s♦♥ ❛♥❞ ❙❡rr✐♥ ✳

✵✲✷✶

slide-23
SLIDE 23

❙t❡♣ ✶ ✿ ❊st✐♠❛t❡s ❢♦r s♦❧✉t✐♦♥s ✇✐t❤ ♥✉❧❧ ❉✐r✐❝❤❧❡t ❝♦♥❞✐t✐♦♥s ✉♥❞❡r ✇❡❛❦❡r L1✲✐♥t❡❣r❛❜✐❧✐t② ❝♦♥❞✐t✐♦♥ ♦♥ f 0 ❚❤❡♦r❡♠ ✼ ❚❤❡r❡ ❡①✐sts ❛ ✉♥✐q✉❡ s♦❧✉t✐♦♥ ♦❢ ✭✶✮ ✐♥ H0. ▼♦r❡♦✈❡r✱ t❤✐s s♦❧✉t✐♦♥ ❤❛s ❛ ✈❡rs✐♦♥ ✇✐t❤ L2(O)✲❝♦♥t✐♥✉♦✉s tr❛❥❡❝t♦r✐❡s ❛♥❞ ✐t s❛t✐s✜❡s t❤❡ ❢♦❧❧♦✇✐♥❣ ❡st✐♠❛t❡s E

  • u2

2,∞;t + ∇u2 2,2;t

  • ≤ k (t) E
  • ξ2

2 +

  • f 0

#;t

2 +

  • g0

2

2,2;t +

  • h0

2

2,2;t

  • ,

❢♦r ❡❛❝❤ t ≥ 0, ✇❤❡r❡ k (t) ✐s ❛ ❝♦♥st❛♥t t❤❛t ♦♥❧② ❞❡♣❡♥❞s ♦♥ t❤❡ str✉❝t✉r❡ ❝♦♥st❛♥ts ❛♥❞ t. Pr♦♦❢ ✿ ❲❡ st❛rt ❜② ✇r✐t✐♥❣ ■t♦✬s ❢♦r♠✉❧❛ ❢♦r t❤❡ s♦❧✉t✐♦♥ ✐♥ t❤❡ ❢♦r♠ ut2

2 + 2

t E (us, us) ds = ξ2

2 + 2

t (us, fs (us, ∇us)) ds − 2 t

d

  • i=1

(∂ius, gi,s (us, ∇us)) ds + t hs (us, ∇us)2

2 ds

+ 2

d1

  • j=1

t (us, hj,s (us, ∇us)) dBj

s,

✭✹✮

✵✲✷✷

slide-24
SLIDE 24

❡q✉❛❧✐t② ✇❤✐❝❤ ❤♦❧❞s ❛✳s✳ ❚❤❡ ▲✐♣s❝❤✐t③ ❝♦♥❞✐t✐♦♥ ❛♥❞ t❤❡ ✐♥❡q✉❛❧✐t② ✭✷✮ ❧❡❛❞ t♦ t❤❡ ❢♦❧❧♦✇✐♥❣ ❡st✐♠❛t❡ t (us, fs (us, ∇us)) ds ≤ ε ∇u2

2,2;t + cε u2 2,2;t + δ u2 #;t + cδ

  • f 0

#;t

2 , ✇❤❡r❡ ε, δ > 0 ❛r❡ t✇♦ s♠❛❧❧ ♣❛r❛♠❡t❡rs t♦ ❜❡ ❝❤♦s❡♥ ❧❛t❡r ❛♥❞ cε, cδ ❛r❡ ❝♦♥st❛♥ts ❞❡♣❡♥❞✐♥❣ ♦❢ t❤❡♠✳ ❙✐♠✐❧❛r ❡st✐♠❛t❡s ❤♦❧❞ ❢♦r t❤❡ ♥❡①t t✇♦ t❡r♠s − t

d

  • i=1

(∂ius, gi,s (us, ∇us)) ds ≤ (α + ε) ∇u2

2,2;t + cε u2 2,2;t + cε

  • g0

2

2,2;t ,

t hs (us, ∇us)2

2 ds ≤

  • β2 + ε
  • ∇u2

2,2;t + cε u2 2,2;t + cε

  • h0

2

2,2;t .

❈♦r♦❧❧❛r② ✽ ▲❡t ✉s ❛ss✉♠❡ t❤❡ ❤②♣♦t❤❡s❡s ♦❢ t❤❡ ♣r❡❝❡❞✐♥❣ ❚❤❡♦r❡♠ ✇✐t❤ t❤❡ s❛♠❡ ♥♦t❛t✐♦♥s✳ ▲❡t ϕ : R → R ❜❡ ❛ ❢✉♥❝t✐♦♥ ♦❢ ❝❧❛ss C2 ❛♥❞ ❛ss✉♠❡ t❤❛t ϕ′′ ✐s ❜♦✉♥❞❡❞ ❛♥❞ ϕ′ (0) = 0. ❚❤❡♥ t❤❡ ❢♦❧❧♦✇✐♥❣ r❡❧❛t✐♦♥ ❤♦❧❞s ❛✳s✳ ❢♦r ❛❧❧ t ≥ 0 ✿

  • O

ϕ (ut (x)) dx + t E (ϕ′ (us) , us) ds =

  • O

ϕ (ξ (x)) dx + t (ϕ′ (us) , fs(us, ∇us) ds

✵✲✷✸

slide-25
SLIDE 25

− t

d

  • i=1

(∂i (ϕ′ (us)) , gi,s(us, ∇us) ds + 1 2 t

  • ϕ′′ (us) , |hs(us, ∇us)|2

ds +

d1

  • j=1

t (ϕ′ (us) , hj,s(us, ∇us)) dBj

s.

✵✲✷✹

slide-26
SLIDE 26

❙t❡♣ ✷ ✿ ❊st✐♠❛t❡s ♦❢ t❤❡ ♣♦s✐t✐✈❡ ♣❛rt ♦❢ t❤❡ s♦❧✉t✐♦♥ ❲❡ ♥❡①t ♣r♦✈❡ ❛♥ ❡st✐♠❛t❡ ❢♦r t❤❡ ♣♦s✐t✐✈❡ ♣❛rt u+ ♦❢ t❤❡ s♦❧✉t✐♦♥ u = U (ξ, f, g, h) . ❋♦r t❤✐s ✇❡ ♥❡❡❞ t❤❡ ❢♦❧❧♦✇✐♥❣ ♥♦t❛t✐♦♥ ✿ f u,0 = 1{u>0}f 0, gu,0 = 1{u>0}g0, hu,0 = 1{u>0}h0, f u = f − f 0 + f u,0, gu = g − g0 + gu,0, hu = h − h0 + hu,0 f u,0+ = 1{u>0}

  • f 0 ∨ 0
  • , ξ+ = ξ ∨ 0.

❚❤❡♦r❡♠ ✾ ❚❤❡ ♣♦s✐t✐✈❡ ♣❛rt ♦❢ t❤❡ s♦❧✉t✐♦♥ s❛t✐s✜❡s t❤❡ ❢♦❧❧♦✇✐♥❣ ❡st✐♠❛t❡ E

  • u+

2

2,∞;t +

  • ∇u+

2

2,2;t

  • ≤ k (t) E
  • ξ+

2

2 +

  • f u,0+

#;t

2 +

  • gu,0

2

2,2;t +

  • hu,0

2

2,2;t

  • .

Pr♦♦❢ ✿ ❚❤❡ ✐❞❡❛ ✐s t♦ ❛♣♣❧② ■t♦✬s ❢♦r♠✉❧❛ t♦ t❤❡ ❢✉♥❝t✐♦♥ ψ ❞❡✜♥❡❞ ❜② ψ (y) = (y+)2 , ❢♦r ❛♥② y ∈ R.

  • ❙✐♥❝❡ t❤✐s ❢✉♥❝t✐♦♥ ✐s ♥♦t ♦❢ t❤❡ ❝❧❛ss C2 ✇❡ s❤❛❧❧ ♠❛❦❡ ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ❛s ❢♦❧❧♦✇s✳ ▲❡t ϕ ❜❡

❛ C∞ ❢✉♥❝t✐♦♥ s✉❝❤ t❤❛t ϕ (y) = 0 ❢♦r ❛♥② y ∈] − ∞, 1] ❛♥❞ ϕ (y) = 1 ❢♦r ❛♥② y ∈ [2, ∞[. ❲❡ s❡t ψn (y) = y2ϕ (ny) , ❢♦r ❡❛❝❤ y ∈ R ❛♥❞ ❛❧❧ n ∈ N∗. ■t ✐s ❡❛s② t♦ ✈❡r✐❢② t❤❛t (ψn)n∈N∗ ❝♦♥✈❡r❣❡s ✉♥✐❢♦r♠❧② t♦ t❤❡ ❢✉♥❝t✐♦♥ ψ ❛♥❞ t❤❛t lim

n→∞ ψ′ n (y) = 2y+, lim n∞ ψ′′ n (y) = 2 · 1{y>0},

✵✲✷✺

slide-27
SLIDE 27

❢♦r ❛♥② y ∈ R. ▼♦r❡♦✈❡r ✇❡ ❤❛✈❡ t❤❡ ❡st✐♠❛t❡s 0 ≤ ψn (y) ≤ ψ (y) , 0 ≤ ψ′ (y) ≤ Cy, |ψ′′

n (y)| ≤ C,

❢♦r ❛♥② y ≥ 0 ❛♥❞ ❛❧❧ n ∈ N∗, ✇❤❡r❡ C ✐s ❛ ❝♦♥st❛♥t✳ ❙t❡♣ ✸ ✿ ❊①t❡♥s✐♦♥ ♦❢ t❤❡ ■t♦✬s ❢♦r♠✉❧❛ ❚❤❡ ❢♦❧❧♦✇✐♥❣ t❤❡♦r❡♠ r❡♣r❡s❡♥ts ❛ ❦❡② t❡❝❤♥✐❝❛❧ r❡s✉❧t ✇❤✐❝❤ ❧❡❛❞s t♦ ❛ ❣❡♥❡r❛❧✐③❛t✐♦♥ ♦❢ t❤❡ ❡st✐♠❛t❡s ♦❢ t❤❡ ♣♦s✐t✐✈❡ ♣❛rt✳ ▲❡t u ∈ Uloc (ξ, f, g, h) ❜❡ ❛ s♦❧✉t✐♦♥ ❛♥❞ u+ ✐ts ♣♦s✐t✐✈❡ ♣❛rt ❛♥❞ s❡t f u,0 = 1{u>0}f 0, gu,0 = 1{u>0}g0, hu,0 = 1{u>0}h0, f u,0+ = 1{u>0}

  • f 0 ∨ 0
  • , ξ+ = ξ ∨ 0.

✵✲✷✻

slide-28
SLIDE 28

❚❤❡♦r❡♠ ✶✵ ❆ss✉♠❡ t❤❛t u+ ❜❡❧♦♥❣s t♦ H ❛♥❞ ❛ss✉♠❡ t❤❛t t❤❡ ❞❛t❛ s❛t✐s❢② t❤❡ ❢♦❧❧♦✇✐♥❣ ✐♥t❡❣r❛❜✐❧✐t② ❝♦♥❞✐t✐♦♥s E

  • ξ+

2

2 < ∞, E

  • f u,0

#;t

2 < ∞, E

  • gu,0

2

2,2;t < ∞, E

  • hu,0

2

2,2;t < ∞,

❢♦r ❡❛❝❤ t ≥ 0. ▲❡t ϕ : R → R ❜❡ ❛ ❢✉♥❝t✐♦♥ ♦❢ ❝❧❛ss C2, ✇❤✐❝❤ ❛❞♠✐ts ❛ ❜♦✉♥❞❡❞ s❡❝♦♥❞ ♦r❞❡r ❞❡r✐✈❛t✐✈❡ ❛♥❞ s✉❝❤ t❤❛t ϕ′ (0) = 0. ❚❤❡♥ t❤❡ ❢♦❧❧♦✇✐♥❣ r❡❧❛t✐♦♥ ❤♦❧❞s✱ ❛✳s✳✱ ❢♦r ❡❛❝❤ t ≥ 0,

  • O

ϕ

  • u+

t (x)

  • dx +

t E

  • ϕ′

u+

s

  • , u+

s

  • ds =
  • O

ϕ

  • ξ+ (x)
  • dx +

t

  • ϕ′

u+

s

  • , fs
  • u+

s , ∇u+ s

  • ds

− t

d

  • i=1
  • ϕ′′

u+

s

  • ∂iu+

s , gi,s

  • u+

s , ∇u+ s

  • ds + 1

2 t

  • ϕ′′

u+

s

  • ,
  • hs
  • u+

s , ∇u+ s

  • 2

ds +

d1

  • j=1

t

  • ϕ′

u+

s

  • , hj,s
  • u+

s , ∇u+ s

  • dBj

s.

✵✲✷✼

slide-29
SLIDE 29

❙t❡♣ ✹ ✿ ❊st✐♠❛t❡s ❈♦r♦❧❧❛r② ✶✶ ❯♥❞❡r t❤❡ ❤②♣♦t❤❡s❡s ♦❢ t❤❡ ❛❜♦✈❡ t❤❡♦r❡♠ ✇✐t❤ s❛♠❡ ♥♦t❛t✐♦♥s✱ ♦♥❡ ❤❛s t❤❡ ❢♦❧❧♦✇✐♥❣ ❡st✐♠❛t❡s E

  • u+

2

2,∞;t +

  • ∇u+

2

2,2;t

  • ≤ k (t) E
  • ξ+

2

2 +

  • f u,0+

#;t

2 +

  • gu,0

2

2,2;t +

  • hu,0

2

2,2;t

  • .

❆s ❛ ❈♦♥s❡q✉❡♥❝❡ ✿ ▼♦r❡ ❣❡♥❡r❛❧ ❝♦♠♣❛r✐s♦♥ ❚❤❡♦r❡♠

❚❤❡♦r❡♠ ✶✷ ❆ss✉♠❡ t❤❛t f 1, f

2 ❛r❡ t✇♦ ❢✉♥❝t✐♦♥s s✐♠✐❧❛r t♦ f ✇❤✐❝❤ s❛t✐s❢② t❤❡ ▲✐♣s❝❤✐t③

❝♦♥❞✐t✐♦♥ ❛♥❞ s✉❝❤ t❤❛t ❜♦t❤ tr✐♣❧❡s (f 1, g, h) ❛♥❞ (f 2, g, h) s❛t✐s❢② ♦✉r ❛ss✉♠♣t✐♦♥s✳ ❆ss✉♠❡ t❤❛t ξ1, ξ2 ❛r❡ r❛♥❞♦♠ ✈❛r✐❛❜❧❡s s✐♠✐❧❛r t♦ ξ✳ ▲❡t ui ∈ Uloc (ξi, f i, g, h) , i = 1, 2 ❛♥❞ s✉♣♣♦s❡ t❤❛t t❤❡ ♣r♦❝❡ss (u1 − u2)+ ❜❡❧♦♥❣s t♦ H0 ❛♥❞ t❤❛t ♦♥❡ ❤❛s E

  • f 1

u2, ∇u2 − f 2 u2, ∇u2 ∗

#;t

2 < ∞, ❢♦r ❡❛❝❤ t ≥ 0. ■❢ ξ1 ≤ ξ2 ❛✳s✳ ❛♥❞ f 1 (u2, ∇u2) ≤ f 2 (u2, ∇u2) ❛✳s✳✱ t❤❡♥ ♦♥❡ ❤❛s u1 ≤ u2 ❛✳s✳

✵✲✷✽

slide-30
SLIDE 30

■❞❡❛ ♦❢ t❤❡ ♣r♦♦❢ ✿ ❚❤❡ ❞✐✛❡r❡♥❝❡ v = u1 − u2 ❜❡❧♦♥❣s t♦ Uloc

  • ξ, f, g, h
  • , ✇❤❡r❡

ξ = ξ1 − ξ2, f (t, ω, x, y, z) = f 1 t, ω, x, y + u2

t (x) , z + ∇u2 t (x)

  • − f 2

t, ω, x, u2

t (x) , ∇u2 t (x)

  • ,

g (t, ω, x, y, z) = g

  • t, ω, x, y + u2

t (x) , z + ∇u2 t (x)

  • − g
  • t, ω, x, u2

t (x) , ∇u2 t (x)

  • ,

h (t, ω, x, y, z) = h

  • t, ω, x, y + u2

t (x) , z + ∇u2 t (x)

  • − h
  • t, ω, x, u2

t (x) , ∇u2 t (x)

  • .

❚❤❡ r❡s✉❧t ❢♦❧❧♦✇s ❢r♦♠ t❤❡ ♣r❡❝❡❞✐♥❣ ❝♦r♦❧❧❛r②✱ s✐♥❝❡ ξ ≤ 0 ❛♥❞ f

0 ≤ 0 ❛♥❞ g0 = h 0 = 0. ✷

✵✲✷✾

slide-31
SLIDE 31

❘❡❢❡r❡♥❝❡s ✿

■✮ ❈❛s❡ ✇✐t❤♦✉t ❞✐✈❡r❣❡♥❝❡ t❡r♠ ✭ ✐✳❡✳ g = 0✮

  • P❛r❞♦✉① ❛♥❞ P❡♥❣ ✿ ❈❧❛ss✐❝❛❧ s♦❧✉t✐♦♥s ♦❢ ❙P❉❊✬s ❛♥❞ t❤❡ ❧✐♥❦ ✇✐t❤ ❇❛❝❦✇❛r❞ ❉♦✉❜❧② ❙❉❊✬s

✭s♠♦♦t❤ ❝♦❡✣❝✐❡♥ts✮✳ Pr♦❜✳ ❚❤❡♦r✳ ❘✳ ❋✐❡❧❞s ✭✶✾✾✹✮

  • ❱✳ ❇❛❧❧② ❛♥❞ ❆✳ ▼✳ ✿ ❙♦❜♦❧❡✈ s♦❧✉t✐♦♥s ♦❢ s❡♠✐❧✐♥❡❛r ❙P❉❊✳ ❏✳ ❚❤❡♦r✳ Pr♦❜✳ ✭✵✶✮✳
  • ❆✳ ▼✳ ✫ ❙❝❤❡✉t③♦✇ ✿ ❙♦❜♦❧❡✈ s♦❧✉t✐♦♥s ✇✐t❤ ❑✉♥✐t❛✲♥♦✐s❡✳ ❏✳ ❚❤❡♦r✳ Pr♦❜✳ ✭✵✷✮✳
  • ❘♦③❦♦s③ ✿ ❇❙❉❊✬s ❛♥❞ P❉❊✬s ✐♥ ❞✐✈❡r❣❡♥❝❡ ❢♦r♠✳ Pr♦❜✳ ❚❤❡♦r✳ ❘✳ ❋✐❡❧❞s ✭✵✸✮✳
  • ▲✳ ❉❡♥✐s ✿ ❙♦❧✉t✐♦♥s ♦❢ ❙P❉❊✬s ❝♦♥s✐❞❡r❡❞ ❛s ❉✐r✐❝❤❧❡t ♣r♦❝❡ss❡s✳ ❇❡r♥♦✉❧❧✐ ✭✵✹✮✳

■■✮ ❈❛s❡ ✇✐t❤ ❞✐✈❡r❣❡♥❝❡ t❡r♠ ✿

  • ●②¨
  • ♥❣② ❛♥❞ ❘♦✈✐r❛ ✿ Lp✲♥♦r♠ ❡st✐♠❛t❡s ❢♦r t❤❡ s♦❧✉t✐♦♥s ♦❢ ❙P❉❊✬s ✭♥♦✲❣r❛❞✐❡♥t ❞❡♣❡♥❞❡♥❝❡

✐♥ t❤❡ ❝♦❡✣❝✐❡♥ts✮✳ ❙P❆ ✭✵✵✮✳

  • ▲✳ ❉❡♥✐s ❛♥❞ ▲✳ ❙t♦✐❝❛ ✿ ❆ ❣❡♥❡r❛❧ ❛♥❛❧②t✐❝❛❧ r❡s✉❧t ❢♦r ♥♦♥✲❧✐♥❡❛r

❙P❉❊✬s ❛♥❞ ❛♣♣❧✐❝❛t✐♦♥s✳ ❊❏P ✭✵✹✮✳

  • ▲✳ ❉❡♥✐s✱ ❆✳ ▼✳ ❛♥❞ ▲✳ ❙t♦✐❝❛ ✿ Lp ❡st✐♠❛t❡s ❢♦r t❤❡ ✉♥✐❢♦r♠ ♥♦r♠ ♦❢ s♦❧✉t✐♦♥s ♦❢ q✉❛s✐❧✐♥❡❛r

❙P❉❊✬s✳ Pr♦❜✳ ❚❤❡♦r✳ ❘✳ ❋✐❡❧❞s ✭✷✵✵✺✮✳

✵✲✸✵