  We propose an information-theoretic model for the transport of waves through
a chaotic cavity in the presence of absorption. The entropy of the S-matrix
statistical distribution is maximized, with the constraint $<Tr SS^{\dagger}>
=\alpha n$: n is the dimensionality of S, and $0\leq \alpha \leq 1, \alpha
=0(1)$ meaning complete (no) absorption. For strong absorption our result
agrees with a number of analytical calculations already given in the
literature. In that limit, the distribution of the individual (angular)
transmission and reflection coefficients becomes exponential -Rayleigh
statistics- even for n=1. For $n\gg 1$ Rayleigh statistics is attained even
with no absorption; here we extend the study to $\alpha <1$. The model is
compared with random-matrix-theory numerical simulations: it describes the
problem very well for strong absorption, but fails for moderate and weak
absorptions. Thus, in the latter regime, some important physical constraint is
missing in the construction of the model.
