Full Counting Statistics and Large Deviations in a Thermal 1D Bose Gas

Abstract

We obtain the distribution of a number of atoms in an interval (full counting statistics) for interacting bosons in one dimension. Our results are valid in the weakly interacting regime in a parametrically large window of temperatures and interval lengths. The obtained distribution significantly deviates from a Gaussian away from the quasicondensate regime, and, for sufficiently short intervals, the probability of large number fluctuations is strongly enhanced.