Difference between open string field theory and closed string field theory

  • Thread starter meteor
  • Start date
  • #26
jeff
Science Advisor
658
1


Originally posted by ranyart
I see that the reply to my post from jeff dissapeared? unless he re-routed it into a different 'sum-over-history'!:wink:

Anyway, I do not think Jeff got the hidden variable contained in the post? It actually relates to the 'Stanford crew', and I must say I agreed totally with his acclamation of the said Theorists, I for one have examined a vast number of their pre-print papers for some while, and I am in awae at their persistence in the devolpment of Inflaton field Evolution theory, if thats a correct term?

Question, what causes Strings? Nature or Theorists?
After Tom pointed out the panic thing I removed my moronic post. But thanks for the sentiments and sorry about that.
 
  • #27
370
0


Originally posted by jeff
After Tom pointed out the panic thing I removed my moronic post. But thanks for the sentiments and sorry about that.
No problem.

I mearly wanted to point out that Linde, is moving into the 'side' of the string camp, but I for one think his work has a great distance to cover and go (I believe he knows this), but if he gets results, then there are not many who can deny his and 'et al', team deserve credit.

My own take is on how we treat Time, and Length are the underlaying problem area's..these are two totally incompatable arena's.


Photons are themselves Dimension-less, they do not acknowledge The Past, Present or Future, Time for photons does not exist, yet we throw these dimensionless quantities around and percieve some sort of Measurement from its action?

It is no wonder that the measurement of the Cosmological Constant Varies so?..me I put Alpha IN THE Past, K IN THE Present ,and Omega IN THE Future, but in a developed Cyclonic structure, as was suggested by Einstein and others.

The Past is Static, Present Dynamic and The future is Static, the Equations (einsteins field) can be motioned into the past, and a static solution will be reached, the static of singularity. Interestingly, if one proceeds into the Future, one also reaches the Static solution??..a Big singular crunch!


The perception is that certain models retrace such fields, and end up in a past or forward dimensional field, that has hidden variables, then they are given a name, such as extra- large-dimensions..or 5-d space (see the link with higher variables?) The background dependence is now 'out-of-bounds', it is in a 'not-present-tense'.

It an automatic perception for Man to think of yesterday, or tomorrow, but the reality is that to measure any entity in a future or past zone, we have take our 'presentday-static' tools with us, and its quite easy to see that the geometry of a , lets say a fixed metre length (rod), will be contracted in a Future field, if the future is in Expansion.

And if one takes the same rod back into the past, it will be of a greater length, because the past is in effect smaller, by Expansion model, than the present. This is a Lorentz action, and Einstein clearly thought this through, borne out in his later years of working in isolation, except for the work done with Nathen Rosen and Boris Podolsky.

For this Paradox, he explained some delacate motions with Rosen and Podolsky.

The result of which is a Three Dimensional Exchange, the EPR!...imagine these three kings..throwing such a rod back and fore to each other in a mental exchange that is Unequalled in all of Perceptive Human thought, some would say the EPR is one of the most evasive and yet most true accounts of Reality.
 
  • #28
jeff
Science Advisor
658
1


Originally posted by ranyart
No problem
I understood this part.
 
  • #29
370
0


Originally posted by jeff
I understood this part.

Originally posted by jeff
I understood this part.
Out of choice no doubt.

Moronic Statements are inherently genetic, so I guess your not to blame. But I do admire your self-evaluation, on this basis only!

Memory operation is not based on copy and paste!

It may be that your capacity to relay rational thinking beween external states(experience) and cortex operators(internal thinking)Relys on the world-sheet that is the correspondence of deluded Humans, whose world sheets do not retraceback to your own neurons?

Expecting the whole of Human thought to comply with a line of thinking that is perhaps non-communicative at best, and confined at worst, is a personal issue that you have to come to terms with?

For Humans memory relates to past events, thinking relates to current events and String speculation does not corrospond to either. Where is Memory when one is not Memorizing?..Where does Thinking go when one is Memorizing?

It is correspondence of reality that allows one to communicate and operate in either realm, if you have no incline of a basic reality other than copy and paste(by default this is where String Theory has its foundation based upon) , then you can only fool some of the people some of the time!
 
  • #30
370
0
Originally posted by jeff
This is going to take quite a bit of typing. I'll get to this sometime this week. Sorry for the delay.
Starting with
In general I have problems understanding how definitions on the worldsheet work out in terms of background propagation.

Then using
V(k) ß ƒÃƒÊƒË(k)VƒÊƒË(k) ß ƒÃƒÊƒË(k) ç dƒÊƒÁ ƒÁabÝaXƒÊÝbXƒËeik⋅X

is a vertex operator coupling strings to fluctuations in the background metric GƒÊƒË. Note that like all vertex operators, V is an integral over the world-sheet since it can be inserted at any point.

Uhmm[?] care to insert this into Present Spacetime? what you mean(and if one goes back to the original paper of Jiangping Hu and Shou-Cheng Zhang) one cannot explicitly transform hydrodynamical modes from within a Boundery to the external boundery, it can only go one-way.

If one inserts a dynamical background that is part of a worldsheet that is not based in 3-dimensional PRESENT spacetime, then effectively you are folding/unfolding space/past/future inwardly, which is exactly what Hu and Zhang mentions in their Paper, I quote;Since the dimension of total configuration space is higher than the dimension of base space, this theory bares similarities to Kaluza-Klein Theory, but with two important differences. First the total confiruration space is topologically non-trivial fiber bundle. Second the iso-spin space does not have a small radius. This leads to the "embarrassment of riches" problem. In order to solve this problem we need to find a mechanism where higher iso-spin states obtain mass gaps dynamically, through interactions. This way the low energy degrees of freedom would scale correctly with the dimension of base space. end
.

Then:The underlying mathematical structure of the current approach is the noncommutative
geometry [18] de ned by Eq. (2). Unlike previous approaches [19], this relation
treats all four Euclidean dimensions on equal footing. If we interpret X4 as energy, which is
dual to time, this quantization rule seem to connect space, time, spin and the fundamental
length unit l0 in an uni ed fashion. In the lowest SO(5) level, there is no ordinary non-relativistic kinetic energy. All the single particle states are representations of this algebra.
The non-trivial features identi ed in this work all have their roots in this algebra.

Now why is it that all string theories have problems with background propergation?[?]
 
  • #31
jeff
Science Advisor
658
1
Originally posted by ranyart
Starting with
In general I have problems understanding how definitions on the worldsheet work out in terms of background propagation.

Then using
V(k) ?ß ƒÃƒÊƒË(k)VƒÊƒË(k) ?ß ƒÃƒÊƒË(k) ?ç dƒÊƒÁ ƒÁab?ÝaXƒÊ?ÝbXƒËeik⋅X

is a vertex operator coupling strings to fluctuations in the background metric GƒÊƒË. Note that like all vertex operators, V is an integral over the world-sheet since it can be inserted at any point.

Uhmm[?] care to insert this into Present Spacetime? what you mean(and if one goes back to the original paper of Jiangping Hu and Shou-Cheng Zhang) one cannot explicitly transform hydrodynamical modes from within a Boundery to the external boundery, it can only go one-way.

If one inserts a dynamical background that is part of a worldsheet that is not based in 3-dimensional PRESENT spacetime, then effectively you are folding/unfolding space/past/future inwardly, which is exactly what Hu and Zhang mentions in their Paper, I quote;Since the dimension of total configuration space is higher than the dimension of base space, this theory bares similarities to Kaluza-Klein Theory, but with two important differences. First the total confiruration space is topologically non-trivial fiber bundle. Second the iso-spin space does not have a small radius. This leads to the "embarrassment of riches" problem. In order to solve this problem we need to find a mechanism where higher iso-spin states obtain mass gaps dynamically, through interactions. This way the low energy degrees of freedom would scale correctly with the dimension of base space. end
.

Then:The underlying mathematical structure of the current approach is the noncommutative
geometry [18] de ned by Eq. (2). Unlike previous approaches [19], this relation
treats all four Euclidean dimensions on equal footing. If we interpret X4 as energy, which is
dual to time, this quantization rule seem to connect space, time, spin and the fundamental
length unit l0 in an uni ed fashion. In the lowest SO(5) level, there is no ordinary non-relativistic kinetic energy. All the single particle states are representations of this algebra.
The non-trivial features identi ed in this work all have their roots in this algebra.

Now why is it that all string theories have problems with background propergation?[?]
I don't doubt your sincerity, but help me out here. Could you begin again by raising just one very specific issue of concern to you in a brief - very very brief - clear and uncomplicated way?
 
  • #32
370
0
Originally posted by jeff
I don't doubt your sincerity, but help me out here. Could you begin again by raising just one very specific issue of concern to you in a brief - very very brief - clear and uncomplicated way?
A Note On The Chern-Simons
And Kodama Wavefunctions

Edward Witten
Institute For Advanced Study, Princeton NJ 08540 USA
Yang-Mills theory in four dimensions formally admits an exact Chern-Simons wavefunction.
It is an eigenfunction of the quantum Hamiltonian with zero energy. It is known to be unphysical for a variety of reasons, but it is still interesting to understand what it describes.
We show that in expanding around this state, positive helicity gauge bosons have positive energy and negative helicity ones have negative energy. We also show that the Chern-Simons state is the supersymmetric partner of the naive fermion vacuum in which one
does not fill the fermi sea. Finally, we give a sort of explanation of “why” this state exists.
Similar properties can be expected for the analogous Kodama wavefunction of gravity.


Ed Witten:In the nonabelian case, and e are not invariant under homotopically non-trivial gauge
transformations. We ignore this. Along with the unnormalizability, lack of CPT invariance, etc., and additional properties that we will see below, this is one more reason that the Chern-Simons
state is formal and does not really correspond to a sensible physical theory.


arXiv:gr-qc/0306083 v1
 
  • #33
jeff
Science Advisor
658
1
Originally posted by ranyart
A Note On The Chern-Simons
And Kodama Wavefunctions

Edward Witten
Institute For Advanced Study, Princeton NJ 08540 USA
Yang-Mills theory in four dimensions formally admits an exact Chern-Simons wavefunction.
It is an eigenfunction of the quantum Hamiltonian with zero energy. It is known to be unphysical for a variety of reasons, but it is still interesting to understand what it describes.
We show that in expanding around this state, positive helicity gauge bosons have positive energy and negative helicity ones have negative energy. We also show that the Chern-Simons state is the supersymmetric partner of the naive fermion vacuum in which one
does not fill the fermi sea. Finally, we give a sort of explanation of “why” this state exists.
Similar properties can be expected for the analogous Kodama wavefunction of gravity.


Ed Witten:In the nonabelian case, and e are not invariant under homotopically non-trivial gauge
transformations. We ignore this. Along with the unnormalizability, lack of CPT invariance, etc., and additional properties that we will see below, this is one more reason that the Chern-Simons
state is formal and does not really correspond to a sensible physical theory.


arXiv:gr-qc/0306083 v1
When I invited you to raise a specific issue, I meant one that is germaine to this thread. There isn't even a question in your post, it's just more terminology that you don't understand. In this last respect, it's spamming.
 
  • #34
656
0


Originally posted by jeff

In quantum systems it's natural to assign to distinguished points nondynamical internal degrees of freedom giving rise to global symmetries, i.e. conserved charges that don't contribute to the hamiltonian or ruin any pre-existing symmetry.
yeah, that sounds like what CVJ says in his book. but that s the first part that i didn t follow. why is it natural to assign nondynamical degrees of freedom to the endpoints of a string? what does the phrase "nondynamical degrees of freedom" even mean? can you give me an example of a more pedestrian quantum theory where we do this? does anything like this ever happen in QED?

In string theory we can charge the endpoints of open strings with chan-paton degrees of freedom. Although these charges may interact with external gauge fields, during interactions of several open strings (open strings interact at their endpoints), they flow only along the world-sheet boundaries swept out by the endpoints and so are conserved. Since chan-paton charges have trivial world-sheet dynamics - that is, world-sheet interactions can't change them - consistency requires that only identically charged endpoints may interact.
they have trivial world sheet dynamics because they don t appear in the lagrangian?

what does it mean? i usually associate conserved charges with some symmetry of the lagrangian, although i guess there are other kinds of charges like topological charges. so where did these conserved charges come from? this all seems very opaque to me.

Originally posted by jeff

If the chan-paton degrees of freedom in the 2D quantum conformal field theory governing the physics of open strings are to be useful, they must produce in the low energy limit the familiar yang-mills interactions of particles as they appear in the arena of QFT.
i guess i can imagine that inserting some charges by hand that lead to Yang-Mills would be useful, but right now, this seems highly artificial to me, i guess because i can t understand where these degrees of freedom came from.

if the goal is to get a yang-mills field, why not just postulate that one of the vector fields in the spectrum carries some nonabelian charge?
 
Last edited:

Related Threads for: Difference between open string field theory and closed string field theory

  • Last Post
Replies
3
Views
3K
Replies
4
Views
6K
Replies
0
Views
1K
Replies
1
Views
759
Replies
1
Views
6K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
3
Views
2K
Replies
2
Views
3K
Top