Cremon, J. C.Jackson, A. D.Karabulut, E. O.Kavoulakis, G. M.Mottelson, B. R.Reimann, S. M.2020-03-262020-03-2620151050-29471094-1622https://dx.doi.org/10.1103/PhysRevA.91.033623https://hdl.handle.net/20.500.12395/32522When a Bose-Einstein-condensed cloud of atoms is given some angular momentum, it forms vortices arranged in structures with a discrete rotational symmetry. For these vortex states, the Hilbert space of the exact solution separates into a "primary" space related to the mean-field Gross-Pitaevskii solution and a "complementary" space including the corrections beyond mean field. Considering a weakly interacting Bose-Einstein condensate of harmonically trapped atoms, we demonstrate how this separation can be used to close the conceptual gap between exact solutions for systems with only a few atoms and the thermodynamic limit for which the mean field is the correct leading-order approximation. Although we illustrate this approach for the case of weak interactions, it is expected to be more generally valid.en10.1103/PhysRevA.91.033623info:eu-repo/semantics/closedAccessArticle913N/AWOS:000352074800005Q1