Skip to main content
10 events
when toggle format what by license comment
Nov 1 at 22:23 history edited LSpice CC BY-SA 4.0
Cramer -> Cramér, Holder -> Hölder, while this is on the front page
Dec 5, 2015 at 20:15 comment added Sealander You are right. I have replaced the inequality with Holder's inequality and followed it through to what I think is a nice result. The shakiest part is now the limit where $q \rightarrow \infty$, but I think it is valid (see $\ell_\infty$ norms)
Dec 5, 2015 at 20:12 history edited Sealander CC BY-SA 3.0
Replaced erroneous inequality with Holder's inequality and followed it through
Nov 24, 2015 at 19:26 comment added Michael Note that: $$E[|G|^2]=E[|G|]^2 \iff Var(|G|)=0 \iff \mbox{$|G|$ is constant with prob 1}$$
Nov 24, 2015 at 11:42 history edited Sealander CC BY-SA 3.0
Typo
Nov 24, 2015 at 11:16 comment added Sealander The inequality was kind of a shot in the dark and the more I think about it, the more I don't think it holds even if you restrict it to zero-mean random variables.
Nov 24, 2015 at 10:09 comment added Sealander I am definitely on weakest ground regarding the inequality, but taking your special case of $G = H$ reduces to $E[G^2] \leq E[|G|]^2$ (keeping the absolute value) which seems like it might hold conditionally on $E[G] = 0$.
Nov 24, 2015 at 4:24 comment added Michael Well, your absolute value inequality does not hold in general. For random variables $G,H$, it reduces to the claim $|E[GH]| \leq E[|G|]E[|H|]$. But let $G=H$ and let $G$ be a nonnegative random variable. This reduces to $E[G^2] \leq E[G]^2$, but this is violated whenever $G$ has nonzero variance.
Nov 24, 2015 at 4:12 comment added Michael Thanks for your interest! I asked this 6 months ago, so I need to recall my line of thought on this problem. I will read over your answer this week when I get a chance.
Nov 23, 2015 at 23:12 history answered Sealander CC BY-SA 3.0