Emergent de Sitter Cosmology from Decaying AdS

Understand

Recent developments in string compactifications demonstrate obstructions to the simplest constructions of low energy cosmologies with positive vacuum energy.

• The existence of obstacles to creating scale-separated de Sitter solutions indicates a UV/IR puzzle for embedding cosmological vacua in a unitary theory of quantum gravity.
• Motivated by this puzzle, we propose an embedding of positive energy Friedmann-Lemaitre-Robertson-Walker cosmology within string theory.
• Our proposal involves confining 4D gravity on a brane which mediates the decay from a non-supersymmetric false AdS5 vacuum to a true vacuum.