Description
We present initial results of a survey for star-forming galaxies in the redshift range 3.8{<~}z{<~}4.5. This sample consists of a photometric catalog of 244 galaxies culled from a total solid angle of 0.23 deg^2^ to an apparent magnitude of I_AB_=25.0. Spectroscopic redshifts in the range 3.61{<~}z{<~}4.81 have been obtained for 48 of these galaxies; their median redshift is <z>=4.13. Selecting these galaxies in a manner entirely analogous to our large survey for Lyman-break galaxies at smaller redshift (2.7{<~}z{<~}3.4) allows a relatively clean differential comparison between the populations and integrated luminosity density at these two cosmic epochs. Over the same range of UV luminosity, the spectroscopic properties of the galaxy samples at z{~}4 and z{~}3 are indistinguishable, as are the luminosity function shapes and the total integrated UV luminosity densities [{rho}_UV_(z=3)/{rho}_UV_(z=4)=1.1{+/_}0.3].
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