Unifying string theory and loop quantum gravity

[kodama]

TL;DR Summary

possible to construct a string theory which is consistent with loop quantum gravity

what do string theorist think of program of unifying string theory and loop quantum gravity?

a recent

arXiv:2407.13807 (hep-th)
[Submitted on 18 Jul 2024]
Quantizing the Bosonic String on a Loop Quantum Gravity Background
Deepak Vaid, Luigi Teixeira de Sousa

With the goal of understanding whether or not it is possible to construct a string theory which is consistent with loop quantum gravity (LQG), we study alternate versions of the Nambu-Goto action for a bosonic string. We consider two types of modifications. The first is a phenomenological action based on the observation that LQG tells us that areas of two-surfaces are operators in quantum geometry and are bounded from below. This leads us to a string action which is similar to that of bimetric gravity. We provide formulations of the bimetric string for both the Nambu-Goto (second order) and Polyakov (first order) formulations. We explore the classical solutions of this action and its quantization and relate it to the conventional string solutions.
The second is an action in which the background geometry is described in terms of the pullback of the connection which describes the bulk geometry to the worldsheet. The resulting action is in the form of a gauged sigma model, where the spacetime co-ordinates are now vectors which transform under ISO(D,1). We find that for the particular case of a constant background connection the action reduces to the bimetric action discussed above. We discuss classical solutions and quantization strategies for this action and its implications for the broader program of unifying string theory and loop quantum gravity.

Comments: Comments/criticisms very welcome; 23 pages, no figures
Subjects: High Energy Physics - Theory (hep-th)
Cite as: arXiv:2407.13807 [hep-th]
(or arXiv:2407.13807v1 [hep-th] for this version)

https://doi.org/10.48550/arXiv.2407.13807

could any string theorist or LQG theorist offer insights into a program of unifying string theory and loop quantum gravity?

are there any one working on a unifying string theory and loop quantum gravity merger ?

should unifying string theory and loop quantum gravity merger be it's own research institute

what If the tiny strings of string theory emerges from loop quantum gravity spin networks via topology but in 4 dimensions of space-time

what If a type of string theory could work in 4 dimensions of loop quantum gravity space-time instead of 10d or 11d?

what about ads/cft and unifying string theory and loop quantum gravity?

 

[jedishrfu]

Hi @kodama,

These questions are all good, although the community of scientists who work in these areas decides on the approach that works for them.

Of course, the goal is the same, but everyone tries a different approach to getting there, so we can't really answer them.

You could survey ArXiv papers to see how the latest research approaches the problem or contact a researcher in the field to see what they think.

I know String Theory is a contentious academic issue, with many scientists angry that it has garnered so many research dollars for so little progress. It's why you see books like Not Even Wrong by Woit.

https://www.theguardian.com/science/2005/sep/19/ideas.g2

 

[kodama]

i wonder if you derive a String of String Theory from Loop Quantum Gravity spin network via topology