Conformally Invariant Braneworld and the Cosmological Constant

TL;DR

This paper presents a six-dimensional conformally invariant braneworld model where the cosmological constant naturally vanishes without fine-tuning, featuring a unique compactification of extra dimensions in a football shape with branes at opposite poles.

Contribution

It introduces a conformally invariant six-dimensional braneworld model with a metric-independent measure, eliminating the need for fine-tuning to achieve zero cosmological constant.

Findings

No fine-tuning required for zero 4D cosmological constant

Extra dimensions compactified in a football shape

Branes located at opposite poles of the compactified sphere

Abstract

A six dimensional braneworld scenario based on a model describing the interaction of gravity, gauge fields and 3+1 branes in a conformally invariant way is described. The action of the model is defined using a measure of integration built of degrees of freedom independent of the metric. There is no need to fine tune any bulk cosmological constant or the tension of the two (in the scenario described here) parallel branes to obtain zero cosmological constant, the only solutions are those with zero 4-D cosmological constant. The two extra dimensions are compactified in a "football" fashion and the branes lie on the two opposite poles of the compact "football-shaped" sphere.