Is there any evidence for AdS/CFT in nature?
JUAN: No. There is no evidence and the duality is a statement of equivalence between two classes of theories. In a very precise way it is not applicable to anything that we know so far because the theories for which we know the duality are very specific and idealized configurations in string theory. However, there are many examples, which are fairly close to theories we have in nature. Interviewer: Are there applications for AdS/CFT? JUAN: It has been used to analyze or to get some intuition about theories in nature. So, for that it has been used and it’s useful as a theoretical tool for analyzing possible behaviors in nature. The nature of the duality is such that when the gravity description is relatively simple the particles on the boundary are very strongly interacting, so they interact a lot with each other. Now, theories of particles where the particles are strongly interacting are generally very difficult to understand and there are very, very few cases where you can understand
