Spin foam model from canonical quantization

In summary, there are several research groups at various universities in France focusing on the spinfoam path integral approach to quantum gravity. These groups are located in Marseille, Monpellier, Lyon, and Tours and are led by prominent researchers such as Rovelli, Perez, Roche, Buffenoir, Alexandrov, Livine, Speziale, and Noui. These groups have recently published several papers related to the spinfoam vertex and are expected to continue making significant contributions to the field.
  • #1
jal
549
0
The “math kids” are hard at work.
http://arxiv.org/PS_cache/arxiv/pdf/0705/0705.3892v1.pdf [Broken]
Spin foam model from canonical quantization
Sergei Alexandrov
26 may 2007
-----------

A quick search of dual 4-simplex found this supplementary information http://www.valdostamuseum.org/hamsmith/FynCkb.html [Broken]
4-dim HyperDiamond Lattice
------------

http://www.fogandonions.com/index.html [Broken]
PHYSICS: Projective Structures, Mass Generation
------------------

http://graphics.idav.ucdavis.edu/research/mat_bou_sur [Broken]
Material Boundary Surfaces
-------------------

If you can follow all of that math then you don’t need to look at a simple version, without math., the pictures in my blog.
jal
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
jal said:
The “math kids” are hard at work.
http://arxiv.org/PS_cache/arxiv/pdf/0705/0705.3892v1.pdf [Broken]
Spin foam model from canonical quantization
Sergei Alexandrov
26 may 2007
...

You've spotted a significant development. He hasn't got a formula for the Lorentzian spinfoam vertex amplitude yet but he is clearly working hard on it.
He cites the recent Rovelli et al paper, discusses it quite a lot. That is his reference [24] which you see all thru the latter half of his paper. Rovelli et al dealt with the Euclidean case which is like a first stage. I think a number of people besides Sergei Alexandrov could be expected to take up the challenge of getting to the next stage. Your link is to the PDF so I will add one here to the abstract in case anyone just wants a quick look at the summary.
http://arxiv.org/abs/0705.3892
Spin foam model from canonical quantization
Sergei Alexandrov

"We suggest a modification of the Barrett-Crane spin foam model of 4-dimensional Lorentzian general relativity motivated by the canonical quantization. The starting point is Lorentz covariant loop quantum gravity. Its kinematical Hilbert space is found as a space of the so-called projected spin networks. These spin networks are identified with the boundary states of a spin foam model and provide a generalization of the unique Barrette-Crane intertwiner. We propose a way to modify the Barrett-Crane quantization procedure to arrive at this generalization: the B field (bi-vectors) should be promoted not to generators of the gauge algebra, but to their certain projection. The modification is also justified by the canonical analysis of Plebanski formulation. Finally, we compare our construction with other proposals to modify the Barret-Crane model."
 
Last edited by a moderator:
  • #3
The two senior people at Montpellier II are Eric Buffenoir and Philippe Roche, I think there is also Karim Noui there.
The 2004 Loops and Spinfoam conference at Marseille was organized by Rovelli and Roche.

Alexandrov got the PhD at Paris around 2004, then he went to Utrecht for postdoc, now he is at Montpellier II. One could say there is a GROUP there who can do significant covariant LQG and spinfoam research if they choose. All these people have impressive research records already.

have to go, will think about this some more later.

there is a network of 3 universities Lyon, Montpellier, and Marseille. Etera Livine is at Lyon, there is that group at Monpellier, and there are Rovelli and Perez and their group at Marseille.. In this research network, they know each other and are accustomed to work together.
suddenly, just in the past 3 or 4 weeks we get 3 papers about the spinfoam vertex one from Lyon (Livine and Speziale) one from Rovelli et al at Marseille, and one from Montpellier.
 
Last edited:
  • #4
marcus said:
...there is a network of 3 universities Lyon, Montpellier, and Marseille. Etera Livine is at Lyon, there is that group at Monpellier, and there are Rovelli and Perez and their group at Marseille.. In this research network, they know each other and are accustomed to work together.
suddenly, just in the past 3 or 4 weeks we get 3 papers about the spinfoam vertex one from Lyon (Livine and Speziale) one from Rovelli et al at Marseille, and one from Montpellier.

to correct a mistake: I am told that Karim Noui is now at Tours.

so there are some four French universities with research cadres in Quantum Gravity forming a kind of network.

Marseille (Rovelli, Perez et al)
Monpellier (Roche, Buffenoir, Alexandrov)
Lyon (Livine, Speziale, and also Freidel when he is not at Perimeter)
Tours (Noui)

the focus seems to be on the spinfoam path integral approach.
 

1. What is the spin foam model from canonical quantization?

The spin foam model from canonical quantization is a proposed method for describing the quantum properties of space-time. It combines the concepts of spin networks and loop quantum gravity to create a framework for studying the dynamics of space-time at a quantum level.

2. How does the spin foam model differ from other approaches to quantum gravity?

The spin foam model differs from other approaches to quantum gravity, such as string theory, in that it does not rely on the existence of extra dimensions or the use of perturbation theory. Instead, it is based on the fundamental principles of quantum mechanics and general relativity.

3. What is the significance of the term "spin foam" in the model's name?

The term "spin foam" refers to the discrete structures that make up space-time in the spin foam model. These structures are composed of spin networks, which represent the quantum states of space-time, and are thought to be the building blocks of the universe at a fundamental level.

4. How is the spin foam model related to loop quantum gravity?

The spin foam model is closely related to loop quantum gravity, as both theories are based on the idea that space-time is made up of discrete, quantized units. However, the spin foam model goes beyond loop quantum gravity by incorporating the dynamics of these units in a way that is consistent with general relativity.

5. What are the potential implications of the spin foam model for our understanding of the universe?

The spin foam model has the potential to provide a more complete and unified understanding of the universe by bridging the gap between quantum mechanics and general relativity. It may also help to resolve some of the paradoxes and problems that arise when trying to combine these two theories, such as the singularity at the center of a black hole.

Similar threads

  • Beyond the Standard Models
Replies
27
Views
5K
Replies
2
Views
1K
  • Beyond the Standard Models
Replies
13
Views
6K
Replies
9
Views
5K
Replies
26
Views
8K
Replies
4
Views
3K
  • Beyond the Standard Models
Replies
2
Views
3K
  • Poll
  • Beyond the Standard Models
Replies
18
Views
7K
  • Beyond the Standard Models
Replies
2
Views
2K
Replies
133
Views
26K
Back
Top