Spin Foam Models for Quantum Gravity and semi-classical limit

Understand

The spinfoam framework is a proposal for a regularized path integral for quantum gravity.

• Spinfoams define quantum space-time structures describing the evolution in time of the spin network states for quantum geometry derived from Loop Quantum Gravity (LQG).
• The construction of this covariant approach is based on the formulation of General Relativity as a topological theory plus the so-called simplicity constraints which introduce local degrees of freedom.
• The simplicity constraints are essential in turning the non-physical topological theory into 4d gravity.