Gauge-Fixing and Residual Symmetries in Gauge/Gravity Theories with Extra Dimensions

Understand

We study compactified pure gauge/gravitational theories with gauge-fixing terms and show that these theories possess quantum mechanical SUSY-like symmetries between unphysical degrees of freedom.

• These residual symmetries are global symmetries and generated by quantum mechanical N=2 supercharges.
• Also, we establish new one-parameter family of gauge choices for higher-dimensional gravity, and calculate as a check of its validity one graviton exchange amplitude in the lowest tree-level approximation.
• We confirm that the result is indeed $\xi$-independent and the cancellation of the $\xi$-dependence is ensured by the residual symmetries.