Baryon oscillations and consistency tests for photometrically determined redshifts of very faint galaxies

We investigate the impact of uncertainties in the photometric redshift error probability distribution on dark energy constraints from detection of baryon acoustic oscillations in galaxy power spectra. We also consider the prospects for determining the photometric redshift error probability distribution from the galaxy power spectra themselves. We find that although a sufficiently precise determination of redshift biases delta z and variances sigma(2)(z) is not possible, a strong consistency test is. For example, if sigma(z) is known to 1%, then any redshift bias delta z greater than 0.008 will be detectable in the proposed survey of the Large Synoptic Survey Telescope through baryon oscillations. We speculate about the utility of this test for interpretation of cosmic shear data.