Early photometric data from the Sloan Digital Sky Survey ( SDSS ) contain angular positions for 1.5 million galaxies .
In companion papers , the angular correlation function w ( \theta ) and 2D power spectrum C _ { l } of these galaxies are presented .
Here we invert Limber ’ s equation to extract the 3D power spectrum from the angular results .
We accomplish this using an estimate of dn / dz , the redshift distribution of galaxies in four different magnitude slices in the SDSS photometric catalog .
The resulting 3D power spectrum estimates from w ( \theta ) and C _ { l } agree with each other and with previous estimates over a range in wavenumbers 0.03 < k / { h Mpc } ^ { -1 } < 1 .
The galaxies in the faintest magnitude bin ( 21 < r ^ { * } < 22 , which have median redshift z _ { m } = 0.43 ) are less clustered than the galaxies in the brightest magnitude bin ( 18 < r ^ { * } < 19 with z _ { m } = 0.17 ) , especially on scales where nonlinearities are important .
The derived power spectrum agrees with that of Szalay et al .
( 2001 ) who go directly from the raw data to a parametric estimate of the power spectrum .
The strongest constraints on the shape parameter \Gamma come from the faintest galaxies ( in the magnitude bin 21 < r ^ { * } < 22 ) , from which we infer \Gamma = 0.14 ^ { +0.11 } _ { -0.06 } ( 95 \% C.L .
) .