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Does anyone know

  1. Jan 16, 2009 #1
    Does anyone know if the strings from string theory arise from the Quantum Field, or Unified Field, by any chance?
     
  2. jcsd
  3. Jan 18, 2009 #2

    malawi_glenn

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    String theory is not a QFT
     
  4. Mar 2, 2009 #3
    To elaborate on malawi glenn,s statement, string theory was developed in the late 1960's by the Italian mathematician Gabrielle Veneziano. In this time before the quark model was fully developed, many theories were offered to describe the gamut of particles being discovered in accelerators. Veneziano discovered that describing particles as tiny one-dimensional entities called strings was a helpful model. Thus was string theory born.
     
  5. Mar 2, 2009 #4
    There is something called string field theory that received a lot of attention before the holographic dualities that are the current hot topic.
     
  6. Mar 3, 2009 #5
    I have never heard of 'string field theory'. Could you please give a brief description?
     
  7. Mar 3, 2009 #6
    There is a page on wikipedia. String field theory as I understand only began to be studied a couple decades after normal string theory.
     
  8. Mar 4, 2009 #7

    Fra

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    I'll interpret the question more generally as in: Is there a way that "strings" can arise from a more fundamental theory (call it what we want) and thus explain them, rather than take them as basic input?

    I think there might be a few ways not yet found. Except for possible unknown possibilities that a future M-theory may comes up with I personally always like another way, which is that strings are built from self-organized abstract information bits, that form string like pattern due to emergent measures on other measures, and that the continuum string are effective as a result of a "large number" approximation.

    I have a personal picture that the position of the string to be an ordered index, that arised as a discrete version of a probability (or an uncertainty measure of a booelan state), then this will produce a continuum. But since again, even the probability may have a physical basis, it's also discrete, which means the string will effectively end up with a finite lenght, rather than infinitely long. In theory one can by the same token imagine very long strings, but they would be more massive and probably wont be very stable, so there might be an explanation to the lenght of strings. Then that's the 1D-index. It's ordered since the index is generated by a probability distribution in a lower dimension, so you can picture conceptually that one side of the string is "false" and the other one is "true", in between there is a classical superposition.

    Then i picture that the string dynamics in the other dimension, is related to how this 1D structure now further relates to additional information, it will flex and swing to response to information. Some information bursts can even cause the string to break for example.

    The word string I used here is though just a personal construct I use and is not really what a string is in sintg theory, but it resembles a string, and I don't rule out that at some point in development it may related to string theory, in which case I think it will provide a decent answer to "why strings". But it would also suggest that strings aren't fundamental, and you can equally come up with another object that wiggles.

    Unfortunately I'm not aware of any papers on this. I hope to come up with one sometime in the future, but so far I focus on working on details.

    I think the point lies at the level, that a certain structure has emerged, as per a specific process, and this process is continuously disturbed, and thus interfering with the process and thus causes the structure to be "excited" or twist around. I think we should trace this to the simplest possible starting point, and I fail to see how a continuum can be the simplest starting point. I think may also be source of much of the problems: because in how many ways can you construct a continuum? more than one, I imagine.

    /Fredrik
     
  9. Mar 4, 2009 #8

    atyy

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  10. Mar 4, 2009 #9

    Fra

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    I think those ideas based on the AdS/CFT duality and other versions of holographic principle is interesting. It's something about it that seem closely related to the ponderings I've made, but a satisfactory form seems still to escape me. That you somehow make transformations between internal and external degrees of freedom, and that this may be a natural way to understand emergence of spacetime dimensionality as well as the microstructure of observers. The theory living on the boundary somehow relates to the communication channels, and the relation between the two theories may have to do with the feedback that drives evolution.

    I hope that there will be found a more clean and general formulation of the holographic principle that can be formulated in an evolutionary context. Maybe even as a relation between evolving data compression/storage algorithms and evolving communication protocols. Maybe the structure of matter is a manifestation of data compression, and the laws of physical interactions are the communication protocols. And maybe neither of thse are absolute, and that there is rather only a relation between them.

    /Fredrik
     
  11. Mar 4, 2009 #10

    MTd2

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    http://arxiv.org/abs/0903.0390

    Singular gauge transformations in string field theory
    Authors: Ian Ellwood
    (Submitted on 2 Mar 2009)

    Abstract: We show that the existence of a tachyon vacuum puts tight restrictions on the form of solutions to the equations of motion of string field theory. In particular, we demonstrate that every solution can be written as a - formal - gauge transformation of the tachyon vacuum. In order for a solution to be non-trivial, this gauge transformation must be singular and we argue that this will happen when the gauge transformation annihilates a projector of the star-algebra. We comment on possible applications of the formalism to finding
     
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