Are Extra Dimensions in String Theory Static or Dynamical?

[ensabah6]

Is string theory's position that the extra 6 dimensions are completely frozen, non-dynamical, static in their specific yau-calibi configuration, for all eternity, each frozen in exactly the same way at every point in space, never changing, while the 4 large dimensions are dynamical, according to GR?

If each of the extra 6 dimensions were curled up in different ways in different points of time, and were dynamical and could change, what would be the ramifications of particle scattering and string properties? Is there anyway to change the configuration of the yau-calibi configuration that would be experimentally doable?

 

[Boris Leykin]

eh?

http://arxiv.org/abs/hep-th/0702220"
Cosmological Moduli Dynamics
Brian Greene, Simon Judes, Janna Levin, Scott Watson, Amanda Weltman
(Submitted on 28 Feb 2007 (v1), last revised 4 Jun 2007 (this version, v2))
Low energy effective actions arising from string theory typically contain many scalar fields, some with a very complicated potential and others with no potential at all. The evolution of these scalars is of great interest. Their late time values have a direct impact on low energy observables, while their early universe dynamics can potentially source inflation or adversely affect big bang nucleosynthesis. Recently, classical and quantum methods for fixing the values of these scalars have been introduced. The purpose of this work is to explore moduli dynamics in light of these stabilization mechanisms. In particular, we explore a truncated low energy effective action that models the neighborhood of special points (or more generally loci) in moduli space, such as conifold points, where extra massless degrees of freedom arise. We find that the dynamics has a surprisingly rich structure - including the appearance of chaos - and we find a viable mechanism for trapping some of the moduli.

 

[ensabah6]

eh?

http://arxiv.org/abs/hep-th/0702220"
Cosmological Moduli Dynamics
Brian Greene, Simon Judes, Janna Levin, Scott Watson, Amanda Weltman
(Submitted on 28 Feb 2007 (v1), last revised 4 Jun 2007 (this version, v2))
Low energy effective actions arising from string theory typically contain many scalar fields, some with a very complicated potential and others with no potential at all. The evolution of these scalars is of great interest. Their late time values have a direct impact on low energy observables, while their early universe dynamics can potentially source inflation or adversely affect big bang nucleosynthesis. Recently, classical and quantum methods for fixing the values of these scalars have been introduced. The purpose of this work is to explore moduli dynamics in light of these stabilization mechanisms. In particular, we explore a truncated low energy effective action that models the neighborhood of special points (or more generally loci) in moduli space, such as conifold points, where extra massless degrees of freedom arise. We find that the dynamics has a surprisingly rich structure - including the appearance of chaos - and we find a viable mechanism for trapping some of the moduli.

well thanks. wouldn't changes in the moduli change the properities of string scattering amplitudes which would be inconsistent with observation?

on the other hand, isn't it unnatural to fix the 6 dimensions eternally, while 4 dimensions are dynamic?

 

[kharranger]

The internal dimensions should not be externally frozen. Their size and shape should be determined dynamically by the theory.

 

[ensabah6]

The internal dimensions should not be externally frozen. Their size and shape should be determined dynamically by the theory.

Once determined dynamically, does it ever change, and if it did change, would that change the particle spectrum?