We estimate the mass density fluctuations power spectrum ( PS ) on large scales by applying a maximum likelihood technique to the peculiar velocity data of the recently completed redshift-distance survey of early-type galaxies ( hereafter ENEAR ) .
Parametric CDM-like models for the PS are assumed , and the best fit parameters are determined by maximizing the probability of the model given the measured peculiar velocities of the galaxies , their distances and estimated errors .
The method has been applied to CDM models with and without COBE normalization .
The general results are in agreement with the high amplitude power spectra found from similar analysis of other independent all-sky catalogs of peculiar velocity data such as MARK III ( Willick et al . 1997 ) and SFI ( Giovanelli et al . 1998 ; da Costa et al . 1996 ) , in spite of the differences in the way these samples were selected , the fact that they probe different regions of space and galaxy distances are computed using different distance relations .
For example , at k = 0.1 h { Mpc ^ { -1 } } the power spectrum value is P ( k ) \Omega ^ { 1.2 } = ( 6.5 \pm 3 ) \times 10 ^ { 3 } ( h ^ { -1 } { Mpc } ) ^ { 3 } and \eta _ { 8 } \equiv \sigma _ { 8 } \Omega ^ { 0.6 } = 1.1 _ { -0.35 } ^ { +0.2 } ; the quoted uncertainties refer to 3 \sigma error level .
We also find that , for \Lambda CDM and OCDM COBE-normalized models , the best-fit parameters are confined by a contour approximately defined by \Omega h ^ { 1.3 } = 0.377 \pm 0.08 and \Omega h ^ { 0.88 } = 0.517 \pm 0.083 respectively . \Gamma -shape models , free of COBE normalization , results in the weak constraint of \Gamma \geq 0.17 and in the rather stringent constraint of \eta _ { 8 } = 1.0 \pm 0.25 .
All quoted uncertainties refer to 3 \sigma confidence-level ( c.l . ) .

The calculated PS has been used as a prior for Wiener reconstruction of the density field at different resolutions and the three-dimensional velocity field within a volume of radius \approx 80 h ^ { -1 } { Mpc } .
All major structures in the nearby universe are recovered and are well matched to those predicted from all-sky redshift surveys .
The robustness of these features has been tested with Constrained Realizations ( CR ) .
Analysis of reconstructed three-dimensional velocity field yields a small bulk flow amplitude ( \sim 160 \pm 60 ~ { } { km s ^ { -1 } } at 60 ~ { } h ^ { -1 } { Mpc } ) and a very small rms value of the tidal field ( \sim 60 ~ { } { km s ^ { -1 } } ) .
The results give further support to the picture that most of the motion of the Local Group arises from mass fluctuations within the volume considered .