  We study the holographic renormalization group (RG) flow triggered by a
classically marginal operator. When a marginal operator deforms a conformal
field theory, it does not yield a nontrivial renormalization group flow at the
classical level. At the quantum level, however, quantum corrections modify a
marginal operator into one of the truly marginal, marginally relevant, and
marginally irrelevant operators and can generate a nontrivial RG flow. We
investigate the holographic description of a RG flow triggered by a marginal
operator with quantum corrections. We look into how the physical quantities of
a deformed theory, a coupling constant and the vacuum expectation value, rely
on the RG scale. We further discuss the holographic description of the trace
anomaly caused by the gluon condensation.
