208 5. ENERGY, MONOTONICITY, AND BREATHERS
so that
JM w^2 dμ 91 Q(g2, w) - JM w^2 dμ 92 Q(g1, w)
'.S 4 ( (1 + c;):g:+l - 1) JM w^2 dμ 91 JM IV'wl~ 1 dμg1
- 4 ( 1-(1 + c;)-n/
2
) JM w^2 dμ 91 JM IV'wl~ 1 dμg 1
- JM w
2
dμ^91 JM w
2
(I ( R^92 - R^91 ) ~~:: I + I ( ~~:: -1) R^91 I) dμ^91
- IJM w
2
( 1-~~::) dμg111/M Rg1 w
2
dμ^91 I·
(In the above estimates we took into account that R may change sign.) Let
fJ ~max { (1 + c;rl^2 - 1, 1 - (1 + c;)-n/^2 }, so that fJ---+ 0 as c;---+ 0. Since
1
1 - dμdμgl^92 I < - fJ ' we have
Hence
Q(g2, w) Q(g1, w)
JM w2dμg2 JM w2dμg1
'.S 4 ((l + c;):g:+i _ (l + c;)-n/2) JM l\7wJ~1 dμg1
JM w dμg2
+ ( (1 + fJ) max IRg2 - Rg1 I + 26 max IRg1 I) (1 + E: r1^2.
Taking w to be a minimizer for Q (g1, ·), we have
,\ (g2) - ,\ (g1)
'.S 4 ( (l + c;):g:+i _ (l + c;)-n/2) (l + c;r12 JM IV'wJ~1 dμg1
JM w dμg1
+ ((1 + fJ) max IR 92 - R 91 I+ 2fJmax IR 91 I) (1 + c;r/^2.