Induced cosmology on a regularized brane in six-dimensional flux compactification

TL;DR

This paper investigates the cosmological evolution on a regularized brane within a six-dimensional flux compactification, revealing high-energy five-dimensional behavior and low-energy issues with negative effective gravity.

Contribution

It introduces a model of induced cosmology on a regularized brane in a 6D flux compactification, analyzing the resulting Friedmann equations and identifying challenges at low energies.

Findings

High-energy cosmology dominated by five-dimensional rho^2 term

Low-energy Friedmann equation with negative effective Newton's constant

Discussion of potential solutions to the negative gravity issue

Abstract

We consider a six-dimensional Einstein-Maxwell system compactified in an axisymmetric two-dimensional space with one capped regularized conical brane of codimension one. We study the cosmological evolution which is induced on the regularized brane as it moves in between known static bulk and cap solutions. Looking at the resulting Friedmann equation, we see that the brane cosmology at high energies is dominated by a five-dimensional rho^2 energy density term. At low energies, we obtain a Friedmann equation with a term linear to the energy density with, however, negative coefficient in the small four-brane radius limit (i.e. with negative effective Newton's constant). We discuss ways out of this problem.