Vilkovisky-DeWitt Effective Action for Einstein Gravity on Kaluza-Klein   Spacetimes $M^4\times S^N$
  We evaluate the divergent part of the Vilkovisky-DeWitt effective action for Einstein gravity on even-dimensional Kaluza-Klein spacetimes of the form $M^{4}\times S^{N}$. Explicit results are given for $N$=2, 4, and 6. Trace anomalies for gravitons are also given for these cases. Stable Kaluza-Klein configurations are sought, unsuccessfully, assuming the divergent part of the effective action dominates the dynamics. 
H. T. Cho and R. Kantowski