What is space-time?

Synopsis

The concept of space-time is a mystery for physicists.  There are many theories which consider the space-time(gravity) as an emergent phenomenon. Emergent means something which is not fundamental and emerges from other things. Thermodynamics is an example of an emergent phenomenon. There are a few models which try to show how gravity and space-time emerge from fundamental laws of physics-archive. In this talk, I am going to talk about one of these ideas which has been highly regarded and will talk about how space-time can be built from entanglement.  This effort is based on the idea of AdS/CFT, which roughly speaking is a duality between a certain class of gravity theories in (n)-dimensions and a Quantum field theory in (n-1)-dimensions with conformal symmetry. I will show how space-time emerges from entanglements between two separate quantum systems, and conversely how it disappears by removing the entanglements between entangled states.