  There is active interest in the extent to which unresolved gamma-ray pulsars
contribute to the galactic diffuse emission, and whether unresolved gamma-ray
pulsars could be responsible for the excess of diffuse galactic emission above
1 GeV which has been observed by EGRET. The diffuse gamma-ray intensity due to
unresolved pulsars is directly linked to the number of objects which should be
observed in the EGRET data. We can therefore use our knowledge of the
unidentified EGRET sources to constrain model parameters like the pulsar birth
rate, their beaming angle, etc. This analysis is based only on the properties
of the six pulsars which have been identified in the EGRET data, and is
independent of choice of a pulsar emission model. We find that pulsars
contribute very little to the diffuse emission at lower energies, whereas above
1 GeV they can account for 18% of the observed intensity in selected regions
for a reasonable number of directly observable gamma-ray pulsars (14). The
latitude distribution of the diffuse emission caused by unresolved pulsars is
narrower than that of the observed diffuse emission. While the excess above 1
GeV gamma-ray energy is observed up to at least 6-8 degrees off the plane, the
pulsar contribution would be small there. Thus pulsars do significantly
contribute to the diffuse galactic gamma-ray emission above 1 GeV, but they can
not be made responsible for all the discrepancy between observed intensity and
model predictions in this energy range.
