What are the different approaches to QG and QM without spacetime?

[astroquest34@gmail.com]

I'm beginning a research on the different approaches to QG (or also
calssical QM) where the attempt to introduce the notion of spacetime
as an emergent concept is made. I would like to find for introductory
material which describes in one (or few) papers these different
approaches giving first an overview on the subject. Can anyone suggest
some? If there is none, please suggest the approaches/theories/
speculations (in string theory, CQG, or even alternative theories) you
believe are actually the most interesting/promising in potentially
describing physics where space and time no longer is a foundation but
only a low energy emerging property.

Thank you, Mark.

 

[Ilja Schmelzer]

On 3 Nov., 16:23, "astroques...@gmail.com" <astroques...@gmail.com>
wrote:
> I'm beginning a research on the different approaches to QG (or also
> calssical QM) where the attempt to introduce the notion of spacetime
> as an emergent concept is made.

See gr-qc/0205035 for my approach.

Ilja

 

[Matej Pavsic]

astroquest34@gmail.com wrote:
> if there is none, please suggest the approaches/theories/
> speculations (in string theory, CQG, or even alternative theories) you
> believe are actually the most interesting/promising in potentially
> describing physics where space and time no longer is a foundation but
> only a low energy emerging property.

There is a number of penetrating papers by J. Barbour
http://arxiv.org/abs/gr-qc/0309089
http://arxiv.org/abs/gr-qc/0012089 (and other related papers
cited in the first reference above),
as well as his book "The End of Times", (Oxford Univ Press, 2000).

See also http://arxiv.org/abs/gr-qc/0610061 (pages 107-163),
and a recent work http://arxiv.org/abs/0712.3660
for my approach.

 

[exponent137]

Fotini Markopoulou write about emergent space-time.
Markopoulou, F.: Space does not exist, so time can. (2008) (http://www.fqxi.org/community/forum/topic/376)

Also
Ambjorn, J., Jurkiewicz, J., Loll, R.: Self-Organizing Quantum Universe. Sci. Am. Jun, 42-49 (2008)
Regards

 

[exponent137]

Theory of Anton Zeilinger and Caslav Brukner have also elements of emergentism, because it concetrates on quantum information (qubit) so without space.