  Pure gravity in (2+1)-dimensions with negative cosmological constant is
classically equivalent Chern-Simons gauge theory with gauge group SO(2; 2),
which may be realized on chiral and antichiral gauge connections. This paper
looks at half-AdS geometries i.e. those with a trivial rightmoving gauge
connection while the left-moving connection is a standard (Banados-Teitelboim-
Zanelli) BTZ connection. These are shown to be related by diffeomorphism to a
BTZ geometry with different mass and angular momentum. Generically this is
over-spinning, leading to a naked closed timelike curves. Other closely related
solutions are also studied. These results suggest that the measure of the
Chern-Simons path integral cannot factorize in a chiral way, if it is to
represent a sum over physically sensible states.

High Energy Physics - Theory