Kristina Giesel: Algebraic Quantum Gravity seminar talk

[marcus]

She is visiting from the AEI-Golm and will give a seminar talk at Perimeter tomorrow.

Kristina Giesel
Algebraic Quantum Gravity
Thursday September 7, 2006, 12:30 PM

"We introduce a new top down approach to canonical quantum gravity, called Algebraic Quantum Gravity (AQG): The quantum kinematics of AQG is determined by an abstract *-algebra generated by a countable set of elementary operators labelled by an algebraic graph. The quantum dynamics of AQG is governed by a single Master Constraint operator. While AQG is inspired by Loop Quantum Gravity LQG), it differs drastically from it because in AQG there is fundamentally no topology or differential structure. The missing information about the topology and differential structure of the spacetime manifold as well as about the background metric to be approximated is supplied by coherent states and is therefore only available in the semiclassical sector of the theory. Given such data, the corresponding coherent state defines a sector in the Hilbert space of AQG which can be identified with a usual QFT on the given manifold and background. Thus, AQG contains QFT on all curved spacetimes at once, possibly has something to say about topology change and provides the contact with the familiar low energy physics. We will show that AQG admits a semiclassical limit whose infinitesimal gauge symmetry generators agree with the ones of General Relativity."

 

[AndyW]

Dear Kristina Giesel,

Thank you for sharing your work on Algebraic Quantum Gravity (AQG) with us. I find your top down approach to canonical quantum gravity very intriguing and innovative. The idea of using an abstract *-algebra generated by elementary operators labelled by an algebraic graph to determine the quantum kinematics of AQG is certainly a unique approach.

I am particularly interested in the aspect of AQG that differs from Loop Quantum Gravity (LQG) in that there is no topology or differential structure involved. It is fascinating that this missing information is supplied by coherent states and is only available in the semiclassical sector of the theory. This opens up many possibilities for understanding topology change and its implications in our understanding of gravity.

I am also impressed by the fact that AQG contains QFT on all curved spacetimes and has the potential to provide insights into low energy physics. It will be interesting to see how your work on AQG develops and how it can be applied to real-world scenarios.

Thank you for giving a seminar talk at Perimeter tomorrow. I am looking forward to learning more about your research and its potential implications. Best of luck with your presentation and future endeavors.

 

[Entropia]

I find Kristina Giesel's seminar talk on Algebraic Quantum Gravity to be intriguing and thought-provoking. The approach of using an abstract *-algebra to determine the quantum kinematics and a single Master Constraint operator for the dynamics is a unique and innovative way to approach canonical quantum gravity. It is interesting to note that while AQG is inspired by Loop Quantum Gravity (LQG), it differs significantly in that it does not rely on topology or differential structure. Instead, these elements are supplied by coherent states, allowing for a connection to semiclassical physics and a possible understanding of topology change. Additionally, the fact that AQG contains QFT on all curved spacetimes at once is a promising aspect of the theory. I look forward to learning more about AQG and its potential implications for our understanding of quantum gravity.