H. Dorn et Hj. Otto, Q(Q)over-bar potential from AdS-CFT relation at T >= 0: Dependence on orientation in internal space and higher curvature corrections, J HIGH EN P, (9), 1998, pp. NIL_20-S12
Within the classical approximation we calculate the static Q (Q) over bar p
otential via the AdS/CFT relation for nonzero temperature and arbitrary int
ernal orientation of the quarks. We use a higher order curvature corrected
target space background. For timelike Wilson loops there arises a critical
line in the orientation-distance plane which is shifted to larger distances
relative to the calculation with uncorrected background. Beyond that line
there is no Q (Q) over bar-force. The overall vanishing of the force for an
tipodal orientation known from zero temperature remains valid. The spacelik
e Wilson loops yield a string tension for a (2+1)-dimensional gauge theory,
independent of the relative internal orientation, but sensitive to the bac
kground correction.