0
$\begingroup$

Let $(X_n)_{n\in\mathbb N}$ be a sequence of independent random variables with the same distribution. The common distribution $\mu$ is such that it is symmetric, that is, $\mu((-\infty,x])=\mu([-x,\infty))$ for every $x\in\mathbb R$, and it has no first moment, that is, $$\int_{-\infty}^{\infty}|x|\,\mathrm d\mu(x)=\infty.$$

Are there any well-known results as to whether $$\frac{X_1+\cdots+X_n}{n}$$ converges in law as $n\to\infty$? My preliminary experimentation (and the fact that the average of Cauchy random variables is Cauchy) seems to me to suggest the possibility that the answer may be positive and the limit distribution is Cauchy, but I’m not sure. Any thoughts would be appreciated.

$\endgroup$
2
  • $\begingroup$ If you want the denominator to be $n$, then this is Law of large numbers, not CLT. There are many posts on MSE about the infinite mean case. $\endgroup$ Commented 5 hours ago
  • $\begingroup$ @KaviRamaMurthy Fair point, although I decided to use the CLT analogy because I expect convergence in law, not almost sure convergence as with LLN. $\endgroup$ Commented 5 hours ago

0

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.