Quantum corrections to broken N=8 supergravity

We show that the one-loop effective potential of spontaneously broken N = 8 supergravity is calculable and finite at all classical four-dimensional Minkowski vacua without tachyons in the spectrum. The reason is that the supertraces of the quadratic and quartic mass matrices vanish along the classically flat directions: Str M2 = Str M4 = 0. We also show that Str M6 = 0 but Str M8 > 0 in a broad class of vacua with broken supersymmetry on a flat background, which includes all those explicitly identified so far. We find analytical and numerical evidence that the corresponding one-loop effective potential is negative definite. © SISSA 2012.