We present a new and simple approach to some of the deviation inequalities
for product measures deeply investigated by M. Talagrand in the recent years.
Our method is based on functional inequalities of Poincaré and logarithmic
Sobolev type and iteration of these inequalities. In particular, we establish
with theses tools sharp deviation inequalities from the mean on norms of sums
of independent random vectors and empirical processes. Concentration for
the Hamming distance may...