The importance of scalar fields as extradimensional metric components in Kaluza-Klein models

TL;DR

This paper explores how scalar fields embedded in extradimensional metrics can geometrically induce matter in four-dimensional spacetime, offering insights into the nature of extra dimensions and their role in cosmology.

Contribution

It introduces a purely geometrical model where scalar fields in the extra dimension generate observable matter without matter Lagrangians, providing a new perspective on matter induction in Kaluza-Klein theories.

Findings

Scalar fields in extra dimensions can produce observable matter effects.

The model explains cosmic features without matter Lagrangians.

Provides an alternative understanding of matter creation from geometry.

Abstract

Extradimensional models are achieving their highest popularity nowadays, among other reasons, because they can plausible explain some standard cosmology issues, such as the cosmological constant and hierarchy problems. In extradimensional models, we can infer that the four-dimensional matter rises as a geometric manifestation of the extra coordinate. In this way, although we still cannot see the extra dimension, we can relate it to physical quantities that are able to exert such a mechanism of matter induction in the observable universe. In this work we propose that scalar fields are those physical quantities. The models here presented are purely geometrical in the sense that no matter lagrangian is assumed and even the scalar fields are contained in the extradimensional metric. The results are capable of describing different observable cosmic features and yield an alternative to ultimately understand the extra dimension and the mechanism in which it is responsible for the creation of matter in the observable universe.