Landscape, Swampland, and Extra Dimensions

TL;DR

This paper explores how swampland conjectures and observational data suggest the small dark energy could be linked to an extra dimension decompactifying, leading to new insights in cosmology and particle physics.

Contribution

It analyzes the fundamental framework connecting swampland ideas with observable cosmological phenomena involving an extra dark dimension.

Findings

Potential dark matter candidates linked to the dark dimension

Decoding neutrino masses through the extra dimension

New cosmological phenomena arising from the dark dimension

Abstract

By combining swampland conjectures with observational data, it was recently suggested that the cosmological hierarchy problem (i.e. the smallness of the dark energy in Planck units) could be understood as an asymptotic limit in field space, corresponding to a decompactification of one extra (dark) dimension of a size in the micron range. In these Proceedings we examine the fundamental setting of this framework and discuss general aspects of the effective low energy theory inherited from properties of the overarching string theory. We then explore some novel phenomenology encompassing the dark dimension by looking at potential dark matter candidates, decoding neutrino masses, and digging into new cosmological phenomena.