Zusammenfassung
In the usual account of eternal inflation the universe is supposed to be a de
Sitter background in which pocket universes nucleate at a steady rate. However
this is metaphysics because there is no way this mosaic structure can be
observed. We don't see the whole universe but only a nearly homogeneous region
within our past light cone. We show that we can use the no-boundary wave
function to calculate small departures from homogeneity within our past light
cone despite the possibility of much larger fluctuations on super horizon
scales. We find that the dominant contribution comes from the history that
exits eternal inflation at the lowest value of the potential and predict, in a
certain class of landscape models, a tensor to scalar ratio of about 10%. In
this way the no-boundary wave function defines a measure for the prediction of
local cosmological observations.
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