1547845447-The_Ricci_Flow_-_Techniques_and_Applications_-_Part_IV__Chow_

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78 29. COMPACT 2-DIMENSIONAL ANCIENT SOLUTIONS


LEMMA 29 .8.
(29.33)
J[!Vvl~2 [[w 2 .p :::; C(p) for p ?_ 1, [[IVvl;2 J[c 1 .a :::; C(a) for a E (0, 1).

PROOF. By the Bochner formula for 682 IVvl;2 (see (29.26)) and by applying
IV"vl2
68 2v = R + ~ - 2v to the term 2 (\7(652v ), V'v) 8 2, we compute that


652 IV'vl~2 = 2 IV^2 vl! 2 + 2 (\7(652v), \7v) 82 + 2 IV'vl~2


I

= 2 \7^2 v l2^2 \^2 ) IVvl~2
82 + -v V IV'vl 82 , \i'v 52 - 2--v 2 -


  • 2 IV'vl~2 + 2 (\7 R , \i'v) 82
    ~B.


By (29.32), (29.25), and (29.7), we have


(29.34) IV ln vi~ = IV'vl~

(^2) :::; C
v
on 52 x (-oo,-1]. From this, (29.28), and l(VR,V'v) 8 2I:::; IVRl 91 :~~q
2
:::; C
(see the remark below), we obtain llB llLP :::; C(p). Thus we conclude (29.33) for
t E (-oo,-1]. D


REMARK 29 .9. Since 0 < R :::; C on (-oo, -1], the derivative estimates imply


that there exist constants Cm < oo such that IV;' R[ 9 :::; Cm on 52 x (-oo, -1].


However, this does not imply bounds for IV'$2Rl 52.


LEMMA 29.10.

[[v3/2Jlc2,a :::; C(a), l[fo\72v[[ca :::; C(a), and [lv2[[c3,a :::; C(a).

P W h h
I
ROOF. e ave t at n v IV"vlv ~2^1 <^1 IV"vl!2^2 1n^2 I IV"vls2 · b d d ·
112 _^2 v 312 + v v 82 v 112 IS oun e m
LP by (29.34) and (29.28) and we have that


~6 2 (v3f2) = v1/2 R _ 2 v3/2 + ~ IV'vl;2
3 5 2 vl/2 '

so that 11652 ( v^312 ) II wr.p :::; C. Hence, on the time interval (-oo, -1], we have that


(29.35)


Since we have ~v^112 V^2 v + ~v-^112 \i'v ® \i'v = \7^2 (v^312 ) E W^1 ·P as well as
v-^112 \i'v ® \i'v E W^1 ·P, it follows from (29.35) that on (-oo, -1],


(29.36) [lfoV^2 v[lw1,p:::; C(p), so llfoV^2 v[lca :::; C(a).


Since 6 52(v^2 ) = 2Rv - 4v^2 + 4 IV'vl~2 ~ D , where llDllw2,p:::; C, we obtain


(29.37) D


LEMMA 29.11.

(29.38)

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