Anomalous condensate fluctuations in strongly interacting superfluids

We show that the condensate occupation of a superfluid Bose liquid quite generally exhibits anomalously large fluctuations at finite temperatures [Formula Presented] In three dimensions, the variance [Formula Presented] of the number [Formula Presented] of particles in the condensate scales nonlinearly with volume V like [Formula Presented] at low T, generalizing the result obtained by Giorgini, Pitaevskii, and Stringari for a weakly interacting Bose gas. In two dimensions there is only a quasicondensate whose fluctuations are of the same order as the mean value.