Dans ce travail, nous présentons une nouvelle caractérisation de la norme des espaces de Besov-Orlicz associés à la $𝒩$-fonction exponentielle $M_{\beta }$ pour $\beta \>0$. Nous utilisons cette nouvelle norme et un lemme de Marcus et Pisier [15], pour démontrer un critère de tension et de régularité dans les espaces de Besov-Orlicz pour $\beta \ge 1$. Nous étudions ensuite dans les espaces de Besov-Orlicz pour $\beta =1$, des théorèmes limites pour les mesures d’occupations du temps local du processus stable symétrique d’indice $1\<\alpha \le 2$, ce qui...

Suppose that $𝒢$ is a finite, connected graph and $X$ is a lazy random walk on $𝒢$. The lamplighter chain $X^{\diamond }$ associated with $X$ is the random walk on the wreath product ${𝒢}^{\diamond }={𝐙}_2\wr 𝒢$, the graph whose vertices consist of pairs $(\underline{f},x)$ where $f$ is a labeling of the vertices of $𝒢$ by elements of ${𝐙}_2=\{0,1\}$ and $x$ is a vertex in $𝒢$. There is an edge between $(\underline{f},x)$ and $(\underline{g},y)$ in ${𝒢}^{\diamond }$ if and only if $x$ is adjacent to $y$ in $𝒢$ and $f_z=g_z$ for all $z\ne x,y$. In each step, $X^{\diamond }$ moves from a configuration $(\underline{f},x)$ by updating $x$ to $y$ using the transition rule of $X$ and then sampling both...

The asymptotics of the probability that the self-intersection local time of a random walk on ${\mathbb{Z}}^d$ exceeds its expectation by a large amount is a fascinating subject because of its relation to some models from Statistical Mechanics, to large-deviation theory and variational analysis and because of the variety of the effects that can be observed. However, the proof of the upper bound is notoriously difficult and requires various sophisticated techniques. We survey some heuristics and some recently elaborated...