Skip to main content

New answers tagged

3 votes
Accepted

$X \in \{-b,0,b\}$ $P$-almost surely if and only if $P(|X| \geq b)=b^{-p}\mathbb{E}|X|^p $

First note that $$\int_{|X|\geq b}b^pdP\le\int_{|X|\geq b}|X|^pdP \le\mathbb{E}(|X|^p).$$ If $P(|X| \geq b)=b^{-p}\mathbb{E}(|X|^p)$ then these two inequalities become equalities. The first one ...
Anne Bauval's user avatar
  • 44.2k
0 votes
Accepted

Prove $f = 0$ Almost Everywhere in $L^1$ Under Given Conditions

One idea thats a bit more explicit is to write $A=\bigcup_{n}\{x: f(x)\geq \frac{1}{n}\}$. Denote $A_{n}=\{x: f(x)\geq \frac{1}{n}\}$, you can cover $A_{n}$ by a countable collection of intervals of ...
Ace's user avatar
  • 112

Top 50 recent answers are included