Besides the Hawking talk on BH information loss, and the public lecture by Roger Penrose on fadishness, wishful thinking, and fantasy in theoretical physics (or words to that effect) there is another interesting thing happening GR17(adsbygoogle = window.adsbygoogle || []).push({});

Baez plenary talk on the state of things in

Loop Quantum Gravity, Quantum Geometry, and Spin Foams

It might get missed if I include it in the hawking GR17 thread, so i will make a separate thread for it.

Here is the abstract from the GR17 program:

--------quote from program-------

John Baez (UC Riverside)

- Loop Quantum Gravity, Quantum Geometry and Spin Foams

The last few years have seen the techniques of loop quantum gravity applied to a growing number of problems. They have been used to compute the entropy of various sorts of black holes, including those with non-minimally coupled matter, for which the entropy is not proportional to the area. Perhaps more importantly, loop quantum gravity has given us a clear picture of the quantum geometry of the horizon, which accounts for the microscopic degrees of freedom responsible for black hole entropy. There are tantalizing connections to Hod's work on quasinormal modes, but these remain mysterious. Combined with traditional ideas on quantum cosmology, loop quantum gravity has led to new insights on how quantization can eliminate the singular behavior of geometry at the big bang - perhaps with testable consequences. Predictions of Lorentz symmetry violation may also be experimentally testable, but these remain controversial. Finally, the dynamics of the theory is being studied with the help of spin foam models. My talk will survey all this work with a bare minimum of technical details.

------end quote----

the language "quantum geometry" has possibilities because

Ambjorn has a book on simplicial gravity called "Quantum Geometry"

published by Cambridge----that's his chosen name for the approach that includes his work with Loll using dynamical triangulations

yet on the other hand "quantum geometry" is what Ashtekar calls what he does.

and Ambjorn's simplex gravity is a close relative of spin foam.

so Baez title is inclusive of several threads that seem on the point of joining

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# Baez talk at GR17

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