In the framework of the Journées de Statisque 2012 in Bruxelles, I presented the paper “Efficient estimation of conditional covariance matrices” made under Jean-Michel Loubes and Clement Marteau direction. You could check the program and the slides of the presentation. Today I will present you some ideas about the problem studied and the solution found …

###### Monthly Archives: May 2012

## The Slutsky’s lemma as an application of the continuous mapping theorem and uniform weak convergence

Photo of Evgeny Evgenievich Slutsky. Sources: MacTutor and Bomkj. Applying the continuous mapping theorem and $latex {(v)}&fg=000000$ from the last post, we get the following theorem Lemma (Slutsky). Let be $latex {X_{n}}&fg=000000$, $latex {X}&fg=000000$ and $latex {Y_{n}}&fg=000000$ random vectors and $latex {c}&fg=000000$ a constant vector. If $latex {X_{n}\rightsquigarrow X}&fg=000000$ and $latex {Y_{n}\rightsquigarrow c}&fg=000000$, then $latex …

We are going to show some relations between the different modes of convergence . These results are very important in practical examples. In the next post we will explain some of them. To proof this theorem, we shall use several times the Portmanteau’s lemma.

From left to right: Eduard Helly, Yurii Vasilevich Prokhorov and Andrei Andreyevich Markov. Source: MacTutor (1, 2, 3) and TellOfVisions. Let me start with a technical lemma that it will be very useful to show the equivalence between weak convergence and uniform tightness (Prohorov’s theorem). 1. The Helly‘s lemma Lemma (Helly’s Lemma) Let $latex {(F_{n})_{n}}&fg=000000$ a …