Runaway dilatonic domain walls

Understand

We explore the stability of domain wall and bubble solutions in theories with compact extra dimensions.

• The energy density stored inside of the wall can destabilize the volume modulus of a compactification, leading to solutions containing either a timelike singularity or a region where space decompactifies, depending on the metric ansatz.
• We determine the structure of such solutions both analytically and using numerical simulations, and analyze how they arise in compactifications of Einstein--Maxwell theory and Type IIB string theory.
• The existence of instabilities has important implications for the formation of networks of topological defects and the population of vacua during eternal inflation.