Triangle Seminars

Abstract:
We study a holographic model dual to a CFT in 2+1 dimensions at finite temperature and chemical potential with a global U(2) symmetry. At large enough chemical potential spontaneous symmetry breaking occurs and breaks the symmetry to U(1). The non-abelian nature of the symmetry and the explicit Lorentz breaking by the chemical potential imply the presence of an ungapped mode with quadratic dispersion relation in the broken phase. Such modes are called Type II Goldstone bosons and have several distinguished features that we study within the framework of this holographic model.

Abstract:
Computation of conformal dimensions in planar N=4 SYM using integrability techniques was a hot topic during the last decade, with more than thousand publications devoted to it. I will tell you about our new results in this domain: Instead of the Y-system used previously, we are now able to encode the conformal dimensions, at any value of the 't Hooft coupling, in much simpler way: through a Riemann-Hilbert problem. This appears to be not only a very beautiful mathematical setup, but also the most efficient approach to explicitly compute the dimensions. For instance, we've analytically computed the so called Konishi anomalous dimension up to 8 loops in perturbation theory. The talk will include a pedagogical overview of the subject, no special knowledge in this domain is required.