Lois locales de la fonction $\omega$ dans presque tous les petits intervalles

For $k\ge 1$ an integer and $x\ge 1$ a real number, let ${\pi }_k(x)$ be the number of integers smaller than $x$ having exactly $k$ distinct prime divisors. Building on recent work of Matom"aki and Radziwi\l\l, we investigate the asymptotic behavior of ${\pi }_k(x+h)-{\pi }_k(x)$ for almost all $x$, when $h$ is very small. We obtain optimal results for $k\asymp {\log }_{2}x$ and close to optimal results for $5\le k\le {\log }_{2}x$. Our method also applies to $y$-friable integers in almost all intervals $[x,x+h]$ when $\frac{\log x}{\log y}\leq (\log x)^{1/6-\varepsilon}$.