Problem:f belongs to L^p_0(X,M,μ) for some 0 < p_0 < ∞
assume μ(X) = 1
Prove lim ║f║_p = exp [∫ log|f|dμ ].
p→0 X
positive part of log|f|is integrable
if ∫ log|f|dμ= -∞
X
in this case lim║f║_p = 0
p→0
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書上給出提示(只po出一小部分)如下:
先考慮|f|> 0 a.e.且以知 lim ∫|f|^p dμ = μ({f≠0})
p→0 X
利用上述及mean value theorem可證得
log║f║_p = (║f║_q)^(-q) ∫|f|^q log |f| dμ for some 0 < q < p
X
請高手提示怎麼證明上面書上給的提示?
※ 編輯: hau 來自: 61.59.223.74 (12/27 02:12)
※ 編輯: hau 來自: 61.59.223.74 (12/27 02:12)