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Originally Posted by NoldorEldar  So, someone asked for AdS/CFT correspondences.....Here is a breif answer:
When computing the supergravity or type IIA or B pending on your conventions and taste for the day, you can by factorizing D=10 spacetime as either S^6xAdS^4 or S^5xAdS^5 compute the partion function and will turn out to be the same as if Yang-Mills theory was living on the sphere and gravity(Einstein or SUGRA) on the AdS^4 or AdS^5. So what does this mean in non-technical terms? Well AdS^4 is regular space-time viewed as a hyperboloid in five-dimensional space solving the quadric t^2-x^2-y^2-z^2-w^2=R^2. By that I have given you also the clue to a fundamental relation in physics, namely the generalized Maldacena conjecture. Now closed loops arise in type II theory and are are characteristic of gravity. Lee Smolin also deduced that after it was deduced by me.(The theorem is simple: Let X be a quantum theory of gravity, then it is necessarily a theory of closed strings.) Holography refers to the part of the background manifold that is not the AdS^4, also referred to as the bulk. If you base one end of the string on the space-time universe AdS^4 then by extending the string randomly in the other directions of the background manifold, namely the sphere and then returning to the same point higher up(Here I have taken away the point at infinity in the sphere and view it instead as R^4 which is the same thing if you add infinity to it.) and go back to the AdS^4 at some later time, which is the same thing as extending the string through the bulk with one side on each boundary. The dynamics in the bulk are described then by Yang-Mills. Lakeisha I can give you a simpler answer but I think you deserve a somewhat accurate answer.  |
Show me your strings, in a test-tube___They don't exist... As Lee Smolin has stated, String Theory, for over thirty years of trying, has shown no fundamental experimental evidence; though the ideas and maths may still lead to better classical understandings of quantum gravity... So, solve quantum gravity, or the unification of quantum and relative physics, and I may listen to you...
Regards,
Lloyd