BPS brane cosmology in N=2 supergravity

TL;DR

This paper explores the dynamics of flat BPS 3-branes within five-dimensional N=2 supergravity, revealing how brane evolution relates to complex structure moduli and discussing potential cosmological implications.

Contribution

It provides new equations for brane dynamics and hypermultiplet fields, and analyzes the stability and evolution of moduli in a supergravity cosmological setting.

Findings

Brane's Hubble parameter correlates with complex structure moduli.

Moduli exhibit early-time instability and decay.

Results align with heavy moduli production and decay in early universe.

Abstract

We study the embedding of flat BPS 3-branes in five dimensional N=2 supergravity theory. We derive the branes' dynamical equations as well as general expressions for the hypermultiplet fields then focus on a single brane and study its time evolution. It is shown that the brane's Hubble parameter correlates with the moduli of the underlying manifold's complex structure. For certain particular solutions, the moduli seem to exhibit an instability; being large valued at early times then rapidly decaying to either zero or some convergent constant value. The possibility of extending these results to the cosmology of our universe is implied and briefly discussed. Our results are in line with the production and decay of heavy moduli in the early universe, as is currently believed in the literature.