- #1

- 46

- 0

## Main Question or Discussion Point

Is it possible to unify both theories ? I think it may be possible

- Thread starter scottbekerham
- Start date

- #1

- 46

- 0

Is it possible to unify both theories ? I think it may be possible

- #2

atyy

Science Advisor

- 13,798

- 2,057

QFT -> spinnetworks

We also know of links between QFT and string theory in what is called AdS/CFT or gauge/gravity duality.

- #3

- 46

- 0

thank you very much

- #4

marcus

Science Advisor

Gold Member

Dearly Missed

- 24,738

- 785

http://arxiv.org/abs/hep-th/0401172

(Submitted on 23 Jan 2004)

"We combine I. background independent Loop Quantum Gravity (LQG) quantization techniques, II. the mathematically rigorous framework of Algebraic Quantum Field Theory (AQFT) and III. the theory of integrable systems resulting in the invariant Pohlmeyer Charges in order to set up the general representation theory (superselection theory) for the closed bosonic quantum string on flat target space. ..."

- #5

marcus

Science Advisor

Gold Member

Dearly Missed

- 24,738

- 785

You can find several other papers by looking for those which cite the 2004 Thiemann.

It is not obvious why one would WANT to "unify LQG with SMT". One might lose valuable/interesting features of both. So it makes sense, when reading the papers, to look for each author's stated motivation---what they hope to achieve.

Here is a more recent (2009) paper of this sort, iook on page 2 of the PDF:

http://arxiv.org/abs/0908.0953

==quote page 2 of Fairbairn Noui Sardelli==

A few years ago, Thiemann [15] reconsidered the Nambu-Goto string and proposed a quantisation of it using the techniques of loop quantum gravity (LQG) [16]. He showed that the LQG techniques, based on background independent quantisation, provides in particular a quantisation of the bosonic string in any dimensions, i.e., there is no need of critical dimensions for the quantum theory to be consistent. This result has sparked off some discussions [17] and certainly deserves to be understood deeper. We think that the algebraic formulation of the bosonic string is a better starting point to test the LQG techniques than the Nambu-Goto string for it admits a lot of similarities with the Ashtekar-Immirzi-Barbero-Holst formulation [18], [19] of general relativity. It is a first order formulation and possesses an Immirzi-type parameter.** In fact, the main motivation of this article is to open an arena for a background independent quantisation of the bosonic string and to compare it to the standard Fock quantisation.** Our goal is to pursue the line of research initiated by Thiemann in the context of the algebraic formulation of strings.

==endquote==

I bolded what I think is the gist, to make it more visible.

It is not obvious why one would WANT to "unify LQG with SMT". One might lose valuable/interesting features of both. So it makes sense, when reading the papers, to look for each author's stated motivation---what they hope to achieve.

Here is a more recent (2009) paper of this sort, iook on page 2 of the PDF:

http://arxiv.org/abs/0908.0953

==quote page 2 of Fairbairn Noui Sardelli==

A few years ago, Thiemann [15] reconsidered the Nambu-Goto string and proposed a quantisation of it using the techniques of loop quantum gravity (LQG) [16]. He showed that the LQG techniques, based on background independent quantisation, provides in particular a quantisation of the bosonic string in any dimensions, i.e., there is no need of critical dimensions for the quantum theory to be consistent. This result has sparked off some discussions [17] and certainly deserves to be understood deeper. We think that the algebraic formulation of the bosonic string is a better starting point to test the LQG techniques than the Nambu-Goto string for it admits a lot of similarities with the Ashtekar-Immirzi-Barbero-Holst formulation [18], [19] of general relativity. It is a first order formulation and possesses an Immirzi-type parameter.

==endquote==

I bolded what I think is the gist, to make it more visible.

Last edited:

- #6

MTd2

Gold Member

- 2,028

- 25

Smolin is another one that worked hard on these matters. A few years ago he gave a long list of such papers:It is not obvious why one would WANT to "unify LQG with SMT". One might lose valuable/interesting features of both. So it makes sense, when reading the papers, to look for each author's stated motivation---what they hope to achieve.

http://golem.ph.utexas.edu/~distler/blog/archives/000855.html#c003826

Pay attention at the end of it.

"For attempts to use LQG methods to discover the background independent formulation of string and M theory:

http://arxiv.org/abs/hep-th/0002009 :

Title: M theory as a matrix extension of Chern-Simons theory

Authors: Lee Smolin

Comments: Latex, 17 pages, no figures

Journal-ref: Nucl.Phys. B591 (2000) 227-242

http://arxiv.org/abs/hep-th/0104050 :

Title: The exceptional Jordan algebra and the matrix string

Authors: Lee Smolin

Comments: LaTex 15 pages, no figures

Subj-class: High Energy Physics - Theory; Quantum Algebra

http://arxiv.org/abs/hep-th/0006137 [abs, ps, pdf, other] :

Title: The cubic matrix model and a duality between strings and loops

Authors: Lee Smolin

Comments: Latex, 32 pages, 7 figures

Subj-class: High Energy Physics - Theory; Quantum Algebra

http://arxiv.org/abs/hep-th/9712148 :

Title: Nonperturbative dynamics for abstract (p,q) string networks

Authors: Fotini Markopoulou, Lee Smolin

Comments: Latex, 12 pages, epsfig, 7 figures, min"

Last edited:

- Last Post

- Replies
- 36

- Views
- 7K

- Replies
- 3

- Views
- 2K

- Replies
- 14

- Views
- 5K

- Replies
- 62

- Views
- 8K

- Last Post

- Replies
- 5

- Views
- 3K

- Replies
- 3

- Views
- 2K

- Replies
- 1

- Views
- 2K

- Replies
- 11

- Views
- 2K

- Last Post

- Replies
- 3

- Views
- 1K

- Last Post

- Replies
- 1

- Views
- 2K