Henderson gives a good talk. He's been working with Abhay Ashtekar on reformulating loop cosmology as a spinfoam-like path integral---also using GFT (group field theory) where a parameter shows up that may have physical interest (possible connection with the cosmological constant). He got questions from several people including Lee Smolin and Laurent Freidel--discussion at the end added to the presentation.(adsbygoogle = window.adsbygoogle || []).push({});

http://pirsa.org/10050018/

Loop Quantum Cosmology and Spin Foams

Adam Henderson

13/05/2010

"Loop quantum gravity and spin foams are two closely related theories of quantum gravity. There is an expectation that the sum over histories or path integral formulation of LQG will take the form of a spin foam, although a rigorous connection between the two is available only in 2+1 gravity. Understanding the relation between them will resolve many open questions of both theories. We probe the connection through an exactly soluble model of loop quantum cosmology. Beginning from the canonical theory we construct aspin foam like expansionof LQC. This construction reveals a number of insights into spin foams including the nature of the continuum limit."

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# Henderson video: spinfoam approach to cosmology

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