In contrast, the acoustic metric is more constrained. Being specified completely by the three scalars
,
, and
, the acoustic metric has at most
degrees of freedom per point
in spacetime. The equation of continuity actually reduces this to
degrees of freedom, which can be
taken to be
and
.
Thus the simple acoustic metric of this section can at best reproduce some subset of the generic metrics of interest in general relativity.
![]() |
http://www.livingreviews.org/lrr-2005-12 |
© Max Planck Society and the author(s)
Problems/comments to |