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1answer
84 views

Review of String Field Theory

Could anybody suggest the comprehensive review of String Field Theory? Original papers are lengthy and it would take quite a long time to read them all.
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1answer
81 views

What is Kaku's equation about?

When Michio Kaku talks about science he often likes to refer to string theory and sometimes to his equation which looks like this (not sure if wrote right): $$L = \Phi^\dagger[i\partial_{\tau}-H]\Phi ...
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2answers
141 views

String Field Theory and AdS/CFT

I am a PhD student and I am choosing the topic to work on in the graduate school. I am interested in various non-perturbative aspects of String Theory. Does anybody know if there were any attempts to ...
4
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0answers
42 views

Brane interactions?

In particle physics, in QFT's, interactions come from the interaction piece in the Lagrangian (action). In string theory, waiting for a complete formulation of SFT, we have to add "by hand" ...
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0answers
185 views

Has Sen quantized superstring fields?

Today I saw a paper by Ashoke Sen titled "BV Master Action for Heterotic and Type II String Field Theories". Is it really the "quantization" of superstring fields for the first time? What can be its ...
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3answers
159 views

What is the general theory that describes the interactions between strings?

What is the general theory that describes the interactions between strings? I mean the basic object in the theory is (closed) string and they have interactions among them. The string theory, as I ...
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1answer
81 views

What is meant by the following divergent formula?

I have encountered the following formula a couple of times (in different physics contexts which I do not have a good understanding of) $$\int_{0}^\infty \frac{dt}{t}e^{-tx}=-\log x$$ Formally one ...
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1answer
101 views

Can the strings in string theory be thought of as troughs in a field?

I figure that string theory is a new breed of QFT which looks at fields in terms of a network of strings and also incorporates gravity into its module, however my question is that since elementary ...
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1answer
174 views

Why do people look for a field formalism for String Theory

String theory was originally formulated from a perturbative description (using quantum mechanics (QM) and replacing points by strings and evaluating path integral). Still, although QM has an upgrade ...
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7answers
9k views

What are the strings in string theory made of?

This is a follow-up to an intriguing question last year about tension in string theory. What are the strings in string theory composed of? I am serious. Strings made of matter are complex objects ...
5
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0answers
80 views

Why is it difficult to construct the Ramond-Ramond sector in Berkovits' SFT?

I've been trying to get familiar with string field theory (SFT) and I've stumbled upon the statement that the Ramond-Ramond (RR) sector of Nathan's SFT has not been constructed yet. Why is that?
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1answer
136 views

A three string tree diagram evaluated in CFT is different from string field theory evaluation

Hi Guys generally when you evaluate the 3 open string tachyon tree level amplitude in CFT, you do a conformal transformation mapping the worldsheet to the upper half of the complex plane and the ...
9
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2answers
984 views

What does second quantization mean in the context of string theory?

String field theory (in which string theory undergoes "second quantization") seems to reside in the backwaters of discussions of string theory. What does second quantization mean in the context of a ...
9
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1answer
161 views

Is there a background independent closed string field theory?

Analogous to the background independent open string field theory by Witten. If there isn't, what are the main stumbling blocks preventing its construction?
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1answer
378 views

Is string theory local?

By locality I mean something like the Atiyah-Segal axioms for Riemannian cobordisms (see e.g. http://ncatlab.org/nlab/show/FQFT). I.e. to any (spacelike) hypersurface in the target we associate a ...
3
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1answer
260 views

Why do strings split in string theory?

In string theory, we are told strings can split and merge if the string coupling is nonzero, even while the worldsheet action remains Nambu-Goto or Polyakov plus a topological term. However, a ...
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1answer
121 views

How to deal with crossing duality and modular invariance in string field theory?

An answer I gave elsewhere. Some cases to ponder over. A closed string splits into two closed strings, which then merge again into a single closed string. The overall string worldsheet has ...