  In an odd-dimensional spacetime, gravity can be formulated as a proper gauge
theory based on the Chern-Simons action for a suitable gauge group. Performing
dimensional reduction, one obtains, as an effective theory, Chamseddine's
even-dimensional topological gravity with the reduced gauge symmetry. This
theory involves a multiplet of scalar fields that appear as a result of the
dimensional reduction, and it is topological in the sense that its action does
not depend on the metric. Focusing primarily on the four-dimensional case, we
use the holographic dictionary to compute one-point correlation functions of
the relevant boundary operators and find that the spin-current can have a
nonzero expectation value in the dual quantum field theory. We also consider
the generalized holographic Weyl anomaly and find that it vanishes. Finally, we
propose a way of computing two-point correlation functions using the
gravitational Wilson lines.
