Gravity as a diffeomorphism invariant gauge theory (new Krasnov paper)

In summary, the conversation is about a new paper by Kirill Krasnov on gravity as a diffeomorphism invariant gauge theory, with a focus on its application to perturbative quantisation. The paper discusses the linearised theory, gauge symmetries, and gauge fixing, and presents the propagator in a simple form similar to that of Yang-Mills theory. The conversation also mentions that this paper is part of a series dating back to 2006 or 2007 and that MTd2 may have some insights on the cosmological constant.
  • #1
marcus
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I'm hoping there will be some comment on this new paper of Kirill Krasnov

http://arxiv.org/abs/1101.4788
Gravity as a diffeomorphism invariant gauge theory
Kirill Krasnov
24 pages
(Submitted on 25 Jan 2011)
"A general diffeomorphism invariant SU(2) gauge theory is a gravity theory with two propagating polarisations of the graviton. We develop this description of gravity, in particular for future applications to the perturbative quantisation. Thus, the linearised theory, gauge symmetries, gauge fixing are discussed in detail, and the propagator is obtained. The propagator takes a simple form of that of Yang-Mills theory with an additional projector on diffeomorphism equivalence classes of connections inserted. In our approach the gravitational perturbation theory takes a rather unusual form in that the Planck length determined from the self-coupling of the graviton is no longer fundamental but becomes a derived quantity."

It is the latest in a series of paper going back to 2006 or 2007. MTd2 called it especially to our attention. He may have a handle on the cosmological constant.

Have to go out, I'll get back to this later.
 
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  • #2
Thanks marcus. But it was you that pointed out the paper. I just asked you privately to open the thread as this subject is not very known to me. :bigrin:
 

1. What is the new Krasnov paper about?

The new Krasnov paper focuses on the concept of gravity as a diffeomorphism invariant gauge theory.

2. What is a diffeomorphism invariant gauge theory?

A diffeomorphism invariant gauge theory is a type of physical theory that is based on the principle of general covariance, which means that the laws of physics remain unchanged under any smooth coordinate transformation.

3. How does the new Krasnov paper contribute to our understanding of gravity?

The new Krasnov paper proposes a new approach to understanding gravity by treating it as a diffeomorphism invariant gauge theory. This allows for a more comprehensive and unified understanding of gravity, as it takes into account the fundamental principles of general covariance and gauge symmetry.

4. What are some potential implications of this new theory?

The new Krasnov paper opens up new possibilities for studying and understanding gravity, as it provides a framework that is compatible with both general relativity and quantum theory. It also has implications for the search for a theory of quantum gravity, as it may help to reconcile the two currently incompatible theories.

5. Are there any criticisms of this new theory?

As with any new scientific theory, there may be criticisms and debates surrounding its validity and applicability. Some may argue that the diffeomorphism invariant gauge theory approach may not be the most accurate or complete way of understanding gravity, and there may be alternative theories that better explain the phenomenon. However, the new Krasnov paper offers a promising new perspective that could potentially lead to significant breakthroughs in our understanding of gravity.

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