Cycling in the Throat

TL;DR

This paper investigates the dynamics of probe D3-branes in warped string backgrounds, revealing that angular momentum induces bouncing and cyclic cosmologies, thus offering new phenomenological insights into brane motion and universe evolution.

Contribution

It introduces the analysis of brane angular momentum effects in warped backgrounds, uncovering phenomena like bouncing and cyclic universes not previously detailed.

Findings

Angular momentum creates a centrifugal barrier leading to bouncing cosmologies.

Existence of bound orbits corresponding to cyclic universes.

Analysis across various backgrounds including AdS5, Klebanov-Tseytlin, and Klebanov-Strassler.

Abstract

We analyse the dynamics of a probe D3-(anti-)brane propagating in a warped string compactification, making use of the Dirac-Born-Infeld action approximation. We also examine the time dependent expansion of such moving branes from the ``mirage cosmology'' perspective, where cosmology is induced by the brane motion in the background spacetime. A range of physically interesting backgrounds are considered: AdS5, Klebanov-Tseytlin and Klebanov-Strassler. Our focus is on exploring what new phenomenology is obtained from giving the brane angular momentum in the extra dimensions. We find that in general, angular momentum creates a centrifugal barrier, causing bouncing cosmologies. More unexpected, and more interesting, is the existence of bound orbits, corresponding to cyclic universes.