Does Verlinde argument imply 3 spatial dimensions and rules out String theory?

[ensabah6]

String theory requires 9 spatial dimensions, M-theory 10.

One followup to Verlinde's paper is this:

http://arxiv.org/abs/1002.0488

Hidden symmetries for thermodynamics and emergence of relativity

Liu Zhao
(Submitted on 2 Feb 2010)
Verlinde recently proposed an idea about the thermodynamic origin of gravity. Though this is a beautiful idea which may resolve many long standing problems in the theories of gravity, it also raises many other problems. In this article I will comment on some of the problems of Verlinde's proposal with special emphasis on the thermodynamical origin of the principle of relativity. It is found that there is a large group of hidden symmetries of thermodynamics which contains the Poincare group of the spacetime for which space is emergent. This explains the thermodynamic origin of the principle of relativity.

One claim is that Verlinde's line of argument rules out higher spatial dimensions than 3, and just as string theory uniquely singles out 10 dimensions, via anomly cancellations, so Verlinde argument picks out 3, consistent with known observation.

Does it also rprovide an alternative string theory's approach to gravity via spin-2 gravitons?

 

[dark_energy]

Hello Ensebah,

I'm studying the Verlinde paper as well - quite interesting.

The questions posed by Liu Zhao are relevant, but it is very early days for this new point of view, and I'd say that it is hard at this stage to offer definite answers. Verlinde's paper http://arxiv.org/abs/1001.0785" is just a first step, mainly based on general heuristic arguments. As far as I know (I've attended a talk by him), there will be a much more rigorous treatment later.

However, the current paper does offer some hints:

section 6.2 - Implications for string theory [...] contains pointers towards the use of open strings (on the 'inside' of the screen) dual with closed strings on the other side - described as 'emergent' and macroscopic as well. However, closed strings might be a very efficient tool as a stepping stone between the microscopic and macroscopic theory.

Erik Verlinde's explanatory notes at http://staff.science.uva.nl/~erikv/page20/page18/page18.html" says under 13/03 - Essential points of the paper:

If the previous papers had made the emergence of gravity so clear, why are people still regarding string theory as the final theory of quantum gravity? Somehow, not everyone was convinced that these similarities mean something, or at least, people had no clear idea of what they mean.

Some people may think that when we develop string theory further that eventually we will learn about this. I am not sure that string theory will necessarily take us in the right direction, if we keep regarding the definition in terms of closed strings as being microscopically defined, or may be equivalent to some other formulation. And not if we keep our eyes closed for emergent phenomena. Gravitons can not be fundamental particles in a theory of emergent space time and gravity.

... which also points to a role for open strings certainly. Also I'm wondering how the degrees of freedom on the 'screen' will be implemented - it might need need multiple dimensions after all.

So, NO, it does NOT imply 3 spatial dimensions necessarily - at least not at this stage!

Cheers!

String theory requires 9 spatial dimensions, M-theory 10.

One followup to Verlinde's paper is this:

http://arxiv.org/abs/1002.0488

Hidden symmetries for thermodynamics and emergence of relativity

Liu Zhao
(Submitted on 2 Feb 2010)
Verlinde recently proposed an idea about the thermodynamic origin of gravity. Though this is a beautiful idea which may resolve many long standing problems in the theories of gravity, it also raises many other problems. In this article I will comment on some of the problems of Verlinde's proposal with special emphasis on the thermodynamical origin of the principle of relativity. It is found that there is a large group of hidden symmetries of thermodynamics which contains the Poincare group of the spacetime for which space is emergent. This explains the thermodynamic origin of the principle of relativity.

One claim is that Verlinde's line of argument rules out higher spatial dimensions than 3, and just as string theory uniquely singles out 10 dimensions, via anomly cancellations, so Verlinde argument picks out 3, consistent with known observation.

Does it also rprovide an alternative string theory's approach to gravity via spin-2 gravitons?