48.7. LIMIT CONDITIONS FOR NEMYTSKII OPERATORS 1589

≤(

b1∣∣∣∣unk (t,ω)

∣∣∣∣p−1V +b2 (t,ω)

)||u(t,ω)||V ,

therefore,∣∣∣∣unk (t,ω)

∣∣∣∣V and consequently

∣∣∣∣znk (t,ω)∣∣∣∣

V ′ are bounded. This follows from48.7.35. Note that

∣∣∣∣znk (t,ω)∣∣∣∣

V ′ is bounded independently of nk because of the assumptionthat A(·, t,ω) is bounded and we just showed that

∣∣∣∣unk (t,ω)∣∣∣∣

V is bounded.Taking a further subsequence if necessary, let unk (t,ω)→ u(t,ω) weakly in U ′ and

unk (t,ω)→ ξ weakly in V . Thus, by density considerations, ξ = u(t,ω). Now, 48.7.37and the limit conditions for pseudomonotone operators imply that the liminf conditionholds.There exists z∞ ∈ A(u(t,ω) , t,ω) such that

lim infk→∞⟨znk (t,ω) ,unk (t,ω)−u(t,ω)⟩ ≥ ⟨z∞,u(t,ω)−u(t,ω)⟩= 0

> limk→∞⟨znk (t,ω) ,unk (t,ω)−u(t,ω)⟩,

which is a contradiction. This completes the proof of the claim.We continue with the proof of the theorem. It follows from this claim that for given ω,

every t /∈ Σω ,lim inf

n→∞⟨zn (t,ω) ,un (t,ω)−u(t,ω)⟩ ≥ 0. (48.7.39)

Also, it is assumed thatlim sup

n→∞

⟨zn,un−u⟩V ≤ 0.

Then from the estimates,∫Ω

∫ T

0

(b3 ||un (t,ω)||pV −b4 (t,ω)−λ |un (t,ω)|2H

)dtdP

≤∫

∫ T

0∥u(t,ω)∥V

(∥un (t,ω)∥p−1 b1 +b2

)dtdP

so it is routine to get ∥un∥V is bounded. This follows from the assumptions, in particular48.7.35.

Now, the coercivity condition 3 shows that if y ∈ V , then

⟨zn (t,ω) ,un (t,ω)− y(t,ω)⟩ ≥ b3 ||un (t,ω)||pV −b4 (t,ω)−λ |un (t,ω)|2H−(

b1 ||un (t,ω)||p−1 +b2 (t,ω))||y(t,ω)||V .

Using p−1 = pp′ , where 1

p +1p′ = 1, the right-hand side of this inequality equals

b3 ||un (t,ω)||pV −b4 (t,ω)−b1 ||un (t,ω)||p/p′ ||y(t,ω)||V−b2 (t,ω) ||y(t,ω)||V −λ |un (t,ω)|2H ,

the last term being bounded independent of t,n by assumption. Thus there exists c(·, ·) ∈L1 ([0,T ]×Ω) and a positive constant C such that

⟨zn (t,ω) ,un (t,ω)− y(t,ω)⟩ ≥ −c(t,ω)−C ||y(t,ω)||pV . (48.7.40)

48.7. LIMIT CONDITIONS FOR NEMYTSKII OPERATORS 1589< (b1 mn, (6.0)||! +52(0,@)) lle (t.0)|lytherefore, ||un, (t,0)| ly and consequently ||Zn, (t,@)||,1 are bounded. This follows from48.7.35. Note that | |Z (t,@) | y 1s bounded independently of ny because of the assumptionthat A (-,t,@) is bounded and we just showed that | |Uny (t, @) | ly is bounded.Taking a further subsequence if necessary, let up, (t,@) — u(t,@) weakly in U’ andUn, (t,@) + § weakly in V. Thus, by density considerations, § = u(t,@). Now, 48.7.37and the limit conditions for pseudomonotone operators imply that the liminf conditionholds.There exists zo. € A (u(t, @) ,t,@) such thatlim inf (Zn (t,@) ,Un, (t,@)—u(t,@)) > (Zo,u(t,@)—u(t,@)) =0— yoo> lim (Zn, (t,@) Un, (t,@) —u(t,@)),kowhich is a contradiction. This completes the proof of the claim.We continue with the proof of the theorem. It follows from this claim that for given @,every t ¢ Lo,lim inf (Zn (t,@) ,Un (t,@) —u(t,@)) >0 (48.7.39)n—-ooAlso, it is assumed thatlim sup (Zn,Un —Uu)y <0.n— ooThen from the estimates,TLf (b3 \un (t.00)|If. —Ba (1,0) —2 lum (t,0)|f,) aeaPr -1< ff \u(t,olly (lun (¢500)|!""' bi +62) deaQ/0so it is routine to get ||u,||,, is bounded. This follows from the assumptions, in particular48.7.35.Now, the coercivity condition 3 shows that if y € Y, then(Zn (t,@) Un (t,@)—y(t,@)) > b3\|un (t,@)||p — ba (t,@) —A lun (t,0)|7,= (b1 lle (t,0)||?"! +52(6,0)) [lv (¢,@)lly-Using p—1= z, where ; + a = |, the right-hand side of this inequality equalsbs ||ttn (t,0)||f — ba (t,@) — dr ||un (t,)|I?"” [Ly lly2—b2 (t,@)||y (t,@)||y —A lun (t, ©) [7the last term being bounded independent of t,n by assumption. Thus there exists c(-,-) €L! ({0,7] x Q) and a positive constant C such that(Zn (t,@) ,Un (t,@) —y(t,@)) 2 —c (t,@) —C\ly(t,@)||p- (48.7.40)