grandes-ecoles 2021 Q34

grandes-ecoles · France · centrale-maths1__mp Not Maths Almost Sure Convergence and Random Series Properties
Let $A > 2$. Deduce that $$\lim_{n \rightarrow +\infty} \frac{1}{n} \mathbb{E}\left(\sum_{\substack{1 \leqslant i \leqslant n \\ |\Lambda_{i,n}| \geqslant A}} |f - P|\left(\Lambda_{i,n}\right)\right) = 0.$$
Let $A > 2$. Deduce that
$$\lim_{n \rightarrow +\infty} \frac{1}{n} \mathbb{E}\left(\sum_{\substack{1 \leqslant i \leqslant n \\ |\Lambda_{i,n}| \geqslant A}} |f - P|\left(\Lambda_{i,n}\right)\right) = 0.$$