  Sensitivity limits of ground-based infrared interferometers using aperture
synthesis are presented. The motivation of this analysis is to compare an
interferometer composed of multiple large telescopes and a single giant
telescope with adaptive optics. In deriving these limits, perfect wavefront
correction by adaptive optics and perfect cophasing by fringe tracking are
assumed. We consider the case in which n beams are pairwise combined at
n(n-1)/2 detectors and the case in which all the n beams are combined at a
single detector. As a case study, we compare the point-source sensitivities of
interferometers composed of nine 10-m diameter telescopes and a 30-m diameter
single telescope with adaptive optics between 1 and 10 microns.
