tom.stoer said:
There is one idea which bothers me for for months: many ideas, dualities etc. in ST are based on large-N relations. What if ST is a large-N approximation to some underlying field theory?
There are a lot of papers on this, both fomr many string theorists and even connecting back to 't Hooft papers from the 70's on strong interactions.Usually when these questions are phrased in a framework that is part of what I think is the problem, so I don't have any comments on this in the original context as I probably wouldn't be asking the question like that at all.
But like I've mentioned before, my one possible optimistic view of ST is based on a possible connection to the view I have, and it's rouglhy that the continuum string is a pretty much associated with the simplest continuum object that emerges as one reconstructs discrete measures on discrete index spaces.
Very simply put, a 1D string embedded in a 2D space, can be associated to a probability distribution. Where the event index, is the string index, and the mass per unit index corresponds to the probability density, or "evidence count per index".
I also associate this "discrete string" to be like the prototype of a simple observer.
In this sense one can also infer a rational action of this simple observer = string that is in line with a kind of entropic dynamics = no need to "postulate" string action from classical mechanics analogies of strings - there would be a deeper informaiton theoretic understaning of string action based on information divergence of encoded in the string.
Now as one consider this in a context of evolving observers, this simple case is complicated, and more complex structure than just "sequences of counts" emerges. It's in this context, I can make sense of the "consistency constraints" that suggests that maximum fitness takes place in special dimensions.
Clearly information wise, a string in the above sense, can be transformed into different structures, that could in the continuum limit be interpreted as either 1D strings in higher dimensions, OR p-D "branes" in some dimensions, or somehow systems thereof. This is really complex though and I'm still struggling with this.
In this view, then also one would get a better understanding of the "embedded space" of the string. In this view, this embedding would not be real, two observers can disagree about the embedding space, and objectivity is only in the _relation_ between observers, and this is evolving as observers do.
So thinking about a string embedded in an higher dimension, is an exernal picture that really isn't right. In the intrinsic picture the embedding is just an expectation of the string itself, that corresponds to a maximally informative and fit representation.
Structures that fail do realize this, will loose their confidence and mass to it's environment, in a darwinian style.
Also this view, could give new views on the landscape problem. The landscape problem is just the problem of single out a preferred observer, and this can be done of course, and this is why the question should be posed differently, and instead of inflating an imaginary non-real landscape leaving us with a choices that are undecidable one should reconstruct the very framework of asking questions.
This is what to me, the discrete reconstruction of the inference is about. It shares view view Ariel Caticha, but it rejects the objectivity of the statistical manifold. My point would be, that each observer really does SEE a difference manifold!
The only managable starting point I see is the unified perspective. This is why my starting point is unification of forces, and I try to understand how the diversity of symmetries emerge as the complexity ALLOWS SO (as we go down the energy scale from unification).
To me, the unification energy scale corresponds not at this point to some definite Joule number, it rather corresponds in my view far as "zero complexity".
/Fredrik
