Cosmology without time: What to do with a possible signature change from
  quantum gravitational origin?
  Within some approaches to loop quantum cosmology, the existence of an
Euclidean phase at high density has been suggested. In this article, we try to
explain clearly what are the observable consequences of this possible
disappearance of time. Depending on whether it is a real fundamental effect or
just an instability in the equation of motion, we show that very different
conclusions should be drawn. We finally mention some possible consequences of
this phenomenon in the black hole sector.
