Bose-Einstein condensation of atoms in a trap

We point out that the local density approximation (LDA) of Oliva is an adaptation of the Thomas-Fermi method, and is a good approximation when epsilon=HBAR omega/kT much less than 1. For the case of scattering length a>0, the LDA leads to a quantitative result, Eq. (14'), easily checked by experiments. Critical remarks are made about the physics of the many-body problem in terms of the scattering length a.