Statistical analysis of the occurrence of periodicities in galaxy redshift data

We investigate some of Tifft's recent statistical analyses of periodicities in extragalactic redshift samples. The values of the periodicities are refinements of those predicted by Lehto. The redshifts have been corrected for the apparent motion of the solar system relative to the cosmic background radiation and have been filtered by applying criteria such as 21 cm profile width and redshift. In all cases except one, our Monte-Carlo simulations show general agreement with Tifft's results. However, we find that one of his analyses is weakened by applying an inappropriate Bernoulli-trials statistic. We apply a new, more straightforward statistic that shows high statistical significance for some of the periodicities. We conclude that although some of Tifft's procedures seem to be open to some criticism, the periodicities are present at a level that is statistically significant.