One-Loop Effective Potential in Scherk–Schwarz Compactifications of Pure d = 5 $d=5$ Supergravities

Abstract

We perform a systematic analysis of the one-loop effective potential of pure $d=5$ supergravities, with supersymmetry fully broken by a Scherk–Schwarz compactification on the circle, as a function of the radial modulus. We discuss the precise correspondence between the effective potential $V_1$ in the full compactified theory and its counterpart $V_{1,red}$ in the reduced theory. We confirm that $V_1$ is finite for any $N>0$, in contrast to $V_{1,red}$. We find that for broken $N=8$ supergravity $V_1$ is negative definite even after accounting for the Kaluza–Klein states. We outline a program for future work where the study of a different kind of Scherk-Schwarz compactifications, still at the field theory level but with at least three extra dimensions, could lead to qualitatively new results.