  Analogue gravity can be used to reproduce the phenomenology of quantum field
theory in curved spacetime and in particular phenomena such as cosmological
particle creation and Hawking radiation. In black hole physics, taking into
account the backreaction of such effects on the metric requires an extension to
semiclassical gravity and leads to an apparent inconsistency in the theory: the
black hole evaporation induces a breakdown of the unitary quantum evolution
leading to the so called information loss problem. Here we show that analogue
gravity can provide an interesting perspective on the resolution of this
problem, albeit the backreaction in analogue systems is not described by
semiclassical Einstein equations. In particular, by looking at the simpler
problem of cosmological particle creation, we show, in the context of
Bose--Einstein condensates analogue gravity, that the emerging analogue
geometry and quasi-particles have correlations due to the quantum nature of the
atomic degrees of freedom underlying the emergent spacetime. The quantum
evolution is, of course, always unitary, but on the whole Hilbert space, which
cannot be exactly factorised a posteriori in geometry and quasi-particle
components. In analogy, in a black hole evaporation one should expect a
continuous process creating correlations between the Hawking quanta and the
microscopic quantum degrees of freedom of spacetime, implying so that only a
full quantum gravity treatment would be able to resolve the information loss
problem by proving the unitary evolution on the full Hilbert space.
