  We consider the large time behavior in two types of equations, posed on the
whole space R^d: the Schr{\"o}dinger equation with a logarithmic nonlinearity
on the one hand; compressible, isothermal, Euler, Korteweg and quantum
Navier-Stokes equations on the other hand. We explain some connections between
the two families of equations, and show how these connections may help having
an insight in all cases. We insist on some specific aspects only, and refer to
the cited articles for more details, and more complete statements. We try to
give a general picture of the results, and present some heuristical arguments
that can help the intuition, which are not necessarily found in the mentioned
articles.
