Periodicity versus selection effects in the redshift distribution of QSOs

Abstract

Periodicities and selection effects in the redshift (Þ) distribution of QSOs have been debated for a long time in the literature. Here we show that peaks and troughs in the redshift distribution of three new samples, claimed to demonstrate the existence of a periodicity, can be interpreted in terms of known selection effects. This analysis confirms earlier findings that the presence of such selection effects seriously weakens any suggestion for periodicity of the form ¡ Ð Ò ½ · Þ µ ÓÒ×Ø Ò Ø .