https://arxiv.org/pdf/0712.0689
13 Gravity duals Throughout these lectures we have been dealing with the original AdS-CFT correspondence, of N = 4 Super Yang-Mills dual to string theory in AdS5×S 5 , since it is the best understood, and one can calculate many quantities. But since 1997, a slew of other cases have been discovered, including theories with less supersymmetry and/or no conformal invariance. In these cases (when there is no conformal field theory, and no AdS space), one can use the term AdS-CFT, but the proper name of the correspondence is gravity-gauge duality, since it relates a gravitational theory (string theory in a certain background) to a gauge theory in less dimensions, via holography. In that case the gravitational background is known as the gravity dual of the gauge theory. I will try to explain some general features of these gravity-gauge dualities, explaining the map between the two theories and giving some explicit examples. Related cases and CFTs First of all, there are two other cases of AdS-CFT, relating string theory in an AdS space with a conformal field theory of maximal supersymmetry living on its boundary. Obviously this is not related to the same 10 dimensional type IIB string theory, since in fact there is a theorem [50] that we have aluded to in the previous section, stating that the only maximally supersymmetric backgrounds of type IIB are 10 dimensional Minkowski space, AdS5 × S 5 , and the maximally supersymmetric pp wave, which is just the Penrose limit of AdS5 × S 5 . They are in fact related to what is know as M-theory, which can be defined as string theory at a large value of the coupling gs. However, the string theory involved is type IIA string theory, with two spinors of opposite chirality, and not the type IIB (spinors of same chirality) that we have been discussing up to now. It was shown by Witten [55] that at large gs, the string coupling in type IIA string theory acts as an 11-th dimension, via the relation gs = (R11/α′ ) 3/2 . This strong coupling theory is known as M theory, and it is not very well defined (since we don’t have a nonperturbative definition of string theory), but we do know that its low energy theory is the unique 11 dimensional supergravity. In 11 dimensions, the unique spinor is made up of the 2 10 dimensional spinors of opposite 10d chirality. Note that type IIB supergravity can still be related to M theory, t
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யங்க் மில் கண்டுபிடித்த என்=4 என்ற பரிணாம நிலையில் "சூப்பர் யங்க்மில் இரட்டைத்தன்மையை" ஏடிஎஸ் சிஃப்டி ஒத்திசைவை "அதிர்விழை"க் கோட்பாட்டுக்கு (ஏடிஎஸ் 5 * எஸ் 5) ஏற்பாடு செய்யும் சமன்பாடு பற்றிய ஆய்வு இது.இதிலிருந்து பல அளவுகள் அறியப்படும்.1997லிருந்து இது மாதிரியான பல வடிவங்கள் வரிசையாக வெளிவந்தன.ஆனால் இதை விட குறைவான "சூப்பர் சிம்மெட்ரியுடனும்" அல்லது மேலும் "ஒத்திசைவு மாறாத
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