DOE RESEARCH AND
NonGaussian Density Perturbations in Inflationary Cosmologies #
T. J. Allen, B. Grinstein and Mark B. Wise +
California Institute of Technology, Pasadena, CA 91125
The primordial mass density fluctuations may have arisen from quantum fluctuations in a
(massless) scalar field that occurred during an inflationary era. We show that it is possible for
primordial mass density fluctuations, which arose in this way, to be highly nonGaussian. We
also show that the ``bad'' infrared properties of the propagator for a massless scalar field in de
Sitter space can translate itself into a power spectrum, for the the twopoint spatial correlation
of objects that do not trace the mass, which behaves like k -3 , at small wave numbers k.
# Work supported in part by the U.S. Department of Energy under Contracts DEAC0381ER40050 and
+ Sloan Fellow.
Limits on the anisotropy of the microwave background radiation restrict the primordial fluc
tuations in the mass density to be small at early times. However, the fluctuations do grow in the
matterdominated era because of gravitational instability. Presumably the primordial fluctua