  In the present study, we investigate the full counting statistics in a
two-terminal Aharonov-Bohm interferometer embedded with an interacting quantum
dot. We introduce a novel saddle-point solution for a cumulant-generating
function, which satisfies the fluctuation theorem and accounts for the
interaction in the mean-field level approximation. Nonlinear transport
coefficients satisfy universal relations imposed by microscopic reversibility,
though the scattering matrix itself is not reversible. The skewness can be
finite even in equilibrium, owing to the interaction and is proportional to the
asymmetric component of nonlinear conductance.
