  We compute some dependence coefficients for the stationary Markov chain whose
transition kernel is the Perron-Frobenius operator of an expanding map $T$ of
$[0, 1]$ with a neutral fixed point. We use these coefficients to prove a
central limit theorem for the partial sums of $f\circ T^i$, when $f$ belongs to
a large class of unbounded functions from $[0, 1]$ to ${\mathbb R}$. We also
prove other limit theorems and moment inequalities.
