4D Effective Theory and Geometrical Approach

TL;DR

This paper explores the 4D effective theory for light Kaluza-Klein modes, emphasizing the importance of including heavy mode contributions to accurately reproduce physical predictions, with analysis of a 6D Einstein-Maxwell model.

Contribution

It demonstrates the necessity of heavy KK mode contributions for the equivalence between effective and geometrical approaches in spontaneous symmetry breaking.

Findings

Heavy KK modes are essential even at Planck scale for correct predictions.

The study analyzes a 6D Einstein-Maxwell model with charged scalar and fermions.

Extensions to non-Abelian and supersymmetric theories are briefly reviewed.

Abstract

We consider the 4D effective theory for the light Kaluza-Klein (KK) modes. The heavy KK mode contribution is generally needed to reproduce the correct physical predictions: an equivalence, between the effective theory and the D-dimensional (or geometrical) approach to spontaneous symmetry breaking (SSB), emerges only if the heavy mode contribution is taken into account. This happens even if the heavy mode masses are at the Planck scale. In particular, we analyze a 6D Einstein-Maxwell model coupled to a charged scalar and fermions. Moreover, we briefly review non-Abelian and supersymmetric extensions of this theory.