Sommerfeld Theory Colloquium, Quantum mechanics is important for determining the geometry of

spacetime. We will review the role of quantum fluctuations that determine

the large scale structure of the universe. In some model universes

we can give an alternative description of the physics in terms

of a theory of particles that lives on its boundary. This implies that

the geometry is an emergent property. Furthermore, entanglement

plays a crucial role in the emergence of geometry. Large amounts of

entanglement are conjectured to give rise to geometric connections,

or wormholes, between distant and non-interacting systems.