EVIDENCE FOR GAUSSIAN INITIAL FLUCTUATIONS FROM THE 1.2 JANSKY IRAS SURVEY

We recover the one-point probability distribution function of the initial density fluctuations (IPDF) from the quasi-linear galaxy density field of the 1.2 Jy IRAS redshift survey smoothed by 10 h(-1) Mpc. The recovery, using the laminar, Eulerian, Zeldovich approximation of Nusser and Dekel, is independent of Omega and is relatively insensitive to linear galaxy biasing in the range 0.5 less than or equal to b less than or equal to 2. Errors due to discrete sampling, the limited survey volume, and the method of recovering the IPDF are evaluated by comparing the IPDF determined from the IRAS data with Monte Carlo IRAS-like catalogs ''observed'' from N-body simulations of cold dark matter models with Gaussian initial conditions. Eight sensitive statistical tests used in this comparison find the IRAS IPDF to be consistent with Gaussian. We provide observational constraints on possible deviations from Gaussianity, which should be obeyed by any theoretical model.