We study the eect of the gravitational Chern-Simons term (GCST) in the (2+1)-dimensional
anti-de Sitter (AdS2+1) geometry. In the context of the gauge gravity, we obtain a black-hole
solution and its boundary Wess-Zumino-Witten (WZW) theory. The Ba~na...
We study the eect of the gravitational Chern-Simons term (GCST) in the (2+1)-dimensional
anti-de Sitter (AdS2+1) geometry. In the context of the gauge gravity, we obtain a black-hole
solution and its boundary Wess-Zumino-Witten (WZW) theory. The Ba~nados-Teitelboim-Zanelli
(BTZ) black-hole solution can still be retrieved but its gravitational mass and angular momentum
are dierent from their inherent values. The deformation of these quantities due to the GCST can be
summarized as a combination of boosting and rescaling. The boundary WZW theory is found to be
chiral, i.e., composed of the right-moving part and the left-moving part with dierent Kac-Moody
levels. We show explicitly that the identication Killing vector used in the Einstein gravity to mode
the AdS2+1 spacetime to make a BTZ black-hole is nothing but the Wilson loop operator accounting
for the holonomy around a point source in the gauge gravity. Assuming pure AdS2+1 spacetime
to be a black-hole vacuum, we show that the statistical entropy from the boundary conformal eld
theory (CFT) system satises the area law.