Why Randall-Sundrum Scenarious are not Compatible with an Orbifolded Fifth Dimension

TL;DR

The paper demonstrates that Randall-Sundrum scenarios with a ${ m Z}_2$ orbifold symmetry are mathematically inconsistent without boundary actions, challenging their integration into higher-dimensional theories like string theory.

Contribution

It clarifies the inconsistency of Randall-Sundrum models with orbifold symmetry due to regularity issues at the orbifold planes, emphasizing the need for boundary actions.

Findings

Randall-Sundrum models lack regularity at orbifold planes without boundary actions.

Such models are mathematically inconsistent in higher-dimensional frameworks.

The paper discusses potential directions to address these issues.

Abstract

We show the (already known) fact that Randall-Sundrum scenarious although compatible with a ${\mathbb{Z}}_2$ orbifold symmetry cannot hold regularity of the fields at the orbifold planes in the absence of boundary actions and respective jumps of the fields. This makes the models mathematical inconsistence and invalidate the inclusion of such models in a higher dimensional theory such as string theory. For completeness we point out some directions already in the literature and in progress.