作者查詢 / doubleN
作者 doubleN 在 PTT [ Math ] 看板的留言(推文), 共103則
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1F推:直接用 Holder ineq or Jensen ineq06/13 00:16
1F推:f in Lp, ∫fg ≦ c║f║ => g in Lq, 1/p + 1/q =106/04 19:22
1F推:u.i. => exist finite interval I s.t.04/30 05:17
2F→:∫_(R\I) dFn < ε04/30 05:20
3F→: => tightness04/30 05:21
4F→:直觀上 u.i.是強收斂的條件 tight是若收斂的條件04/30 07:53
5F→:強收斂 => 弱收斂, 弱收斂 =\=> 強收斂04/30 07:55
6F→:(弱收斂要加上其他條件才能得到強收斂)04/30 07:57
1F推:If w_tt - △w = 0 and w_t = u02/28 09:03
2F→:let e(t) = (1/2)∫(w_t)^2 + |▽w|^2 dx02/28 09:04
3F→:then e'(t) = ∫w_t (w_tt - △w) dx02/28 09:05
4F→:so e'(t) = 0, i.e., e(t) = C for any t02/28 09:07
5F→:hence ∫u^2 = ∫(w_t)^2 ≦ C02/28 09:10
2F推:1.∫|▽u|^2 = λ∫|u|^2 - a∫|u|^202/16 19:13
3F→:a > 0, u =\= 0 => λ > 002/16 19:14
4F→:2.條件夠嗎?02/16 19:20
1F推:let ∫|u|^2=1, then inf[∫|▽u|^2] = λ02/13 06:54
2F→:=> inf [∫|▽u|^2 -λ] = inf [∫|▽u|^2 -λ∫u^2]02/13 06:56
3F→:let L[u] = ∫|▽u|^2 -λ∫u^202/13 06:57
4F→:and vεC^∞ with compact support02/13 07:00
5F→:then d/dt(L[u+tv]) = 0 when t=0 (local minimal)02/13 07:03
6F→:=> ∫(-△u -λu)v = 002/13 07:05
7F→:=> -△u -λu = 002/13 07:05
1F推:這是Evans的習題吧 按他的hint用 Poisson formula02/11 19:49
2F→:以及 mean value property 即可02/11 19:50
4F推:23. 若 m*(A)<∞, 則 A可測 <=> m***(A) = m*(A)10/24 00:47
5F推:對任意的 A, m***(A)≦ m*(A)10/24 00:54
5F推:du/dn 不用是零, 在邊界上積分為零即可07/25 21:04
6F推:推 MMP XDD06/05 18:14