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Dreed42
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How much of the standard model do we have to change/forget in order for quantum loop gravity to work?
It may be useful to forget thinking in terms of Fock basis, i.e. states with a definite number of particles.Dreed42 said:How much of the standard model do we have to change/forget in order for quantum loop gravity to work?
Demystifier said:It may be useful to forget thinking in terms of Fock basis, i.e. states with a definite number of particles.
haushofer said:This topic would suit better in the Beyond The SM subforum,btw
You might be interested in this:Dreed42 said:How much of the standard model do we have to change/forget in order for quantum loop gravity to work?
This is an excellent paper, but has nothing to do with LQG (despite of being written by Rovelli).julian said:On the issue of particles in quantum gravity (and curved spacetime - see refs therein) see "What is a particle?" by Rovelli and Colosi http://fr.arxiv.org/pdf/gr-qc/0409054
I agree with Demystifier about it's being an excellent paper, it clears up important issues, is widely cited in subsequent research, and it kind of MOTIVATES the development of the boundary formalism in LQG which was achieved over the next few years. You need some grip on the background geometry of a bounded region to say what a particle is, and in LQG you can get that by having the amplitudes depend on boundary data. I want to highlight part of what you quoted from their paper:julian said:On the issue of particles in quantum gravity (and curved spacetime - see refs therein) see "What is a particle?" by Rovelli and Colosi http://fr.arxiv.org/pdf/gr-qc/0409054
I should check to see what references [9] and [10] are to be sure about what they are saying here.julian said:They say
"These difficulties become serious in a background-independent quantum context (see for instance [6]). For instance, in loop quantum gravity [6, 7] quantum states of the gravitational field are described in terms of a spin network basis. Can we talk about gravitons, or other particle states, in loop quantum gravity [8]? A common view among relativists is that we cannot, unless we consider the asymptotically flat context. But there should well be a way of describing what a finite-size detector detects, even in a local background-independent theory! Indeed, a recent line of development in loop quantum gravity aims at computing transition amplitudes between particle states [9], using only finite spacetime regions, using a formalism developed in [10] and in [6]. What are those particle states?"
23 citation is actually not that impressive. I think it deserves much more citations. In particular, I think this paper is better than some of my own papers which have more than 60 citations. :Dmarcus said:I agree with Demystifier about it's being an excellent paper, it clears up important issues, is widely cited in subsequent research
Of gravity, or in general? oo)tom.stoer said:I recommend to forget perturbative quantization.
Dreed, I guess the short answer is there's less and less to "change/forget" as time goes on.Dreed42 said:How much of the standard model do we have to change/forget in order for quantum loop gravity to work?
Quantum Loop Gravity is a theoretical framework that attempts to reconcile the principles of quantum mechanics and general relativity to describe the fundamental nature of the universe. It proposes that spacetime is composed of discrete, indivisible units called "loops" and that gravity is a result of the interactions between these loops.
Unlike other theories of gravity, Quantum Loop Gravity does not rely on the concept of a continuous spacetime. Instead, it treats spacetime as a discrete structure and describes the dynamics of this structure using principles from quantum mechanics. Additionally, it is able to explain the phenomenon of black holes without the need for singularities.
One of the major challenges in developing a complete theory of Quantum Loop Gravity is the difficulty of reconciling it with the principles of quantum mechanics. Another challenge is the lack of experimental evidence to test the validity of the theory, as it deals with phenomena that occur at extremely small scales and high energies.
There is ongoing research and debate about whether Quantum Loop Gravity can provide a viable explanation for the origin of the universe. Some theories within the framework suggest that the Big Bang may have been the result of a quantum gravitational phenomenon, but this is still a topic of exploration and speculation.
Quantum Loop Gravity is still in the early stages of development and is considered a highly complex and challenging topic in theoretical physics. While progress has been made, a complete understanding of the theory has not yet been achieved. Further research and experimentation is needed to fully test and refine the theory.