## Holography Seminar

**Time and place**: Tue 2-4 pm, Fisher Room, DWB

**Trinity Term 2017 Talks**:

- 25/04/2017: Koenraad Schalm (Leiden U.) : Disentangling scrambling from hydrodynamics and the membrane paradigm
- 02/05/2017: Richard Davison (Harvard U.):
Diffusion and chaos in holographic systems at non-zero density
: Recent work has uncovered relations between the rate at which chaotic behaviour spreads in strongly interacting quantum systems, and the diffusivities of certain processes in these systems. Focusing mainly on holographic examples, I will explore the extent to which these relations hold in states at non-zero density, where the diffusion of charge and energy are no longer independent processes.**Abstract** - 09/05/2017: No Seminar
- 16/05/2017: No Seminar
- 23/05/2017: Misha Shifman (U.Minnesota) : Critical soliton vortex in 4D YM as a “Little String”
: Recently we found a solitonic vortex string supported in U(2) super-Yang-Mills that appears to be a critical superstring in 10 dimensions R_4 x Y_6 where Y_6 is a noncompact Calabi-Yau manifold. I briefly review this derivation and present new results on the string spectrum. This is the first example of a quantized critical string which is derived from 4D Yang-Mills theory. I discuss some hints for non-supersymmetric Yang-Mills which might be inferred from this example.**Abstract** - 30/05/2017: Marika Taylor (U.Southampton): AdS_3, dilaton gravity and SYK
: In this talk we discuss the role of underlying generalised conformal structure in SYK and 2d dilaton gravity models. Generalised conformal structure is used to deduce features of the holographic dual to the SYK model and to characterise chaotic behaviour in gravitational holographic theories.**Abstract** - 06/06/2017: Oscar Dias (U.Southampton): Localised thermal phases in holography
: Within the gauge/gravity correspondence, black holes are dual to CFT thermal states. I will discuss asymptotically global AdS_5 × S^5 black holes that are localised on the S^5. These are solutions to type IIB supergravity with S^8 horizon topology that dominate the theory in the microcanonical ensemble at small energies. At higher energies, there is a first-order phase transition to AdS_5-Schwarzschild×S^5. By the AdS/CFT correspondence, this transition is dual to spontaneously breaking the SO(6) R-symmetry of N = 4 super Yang-Mills down to SO(5). I will also discuss localised and nonuniform thermal states of super-Yang-Mills on a circle at strong coupling and associated phase transitions that might be soon reproduced by lattice computations.**Abstract** - 13/06/2017: Ben Withers (U.Geneva): Tails of Universality from Non-Equilibrium Steady States
: I will discuss a class of nonequilibrium steady states corresponding to strongly coupled many-body systems which are forced to flow over an obstacle. The obstacle results in a steady nonlinear deformation of the flow which causes compression and refraction. Equivalently these flows may be viewed as describing the bow and wake of a codimension-1 obstacle dragged through an initially stationary plasma at an angle. I will discuss these flows from the point of view of hydrodynamics and in holography where they are dual to non-Killing black branes. Viewing the flow as a stationary analogue of a quench I will show how the long range behaviour is governed by the appropriate stationary analogue of quasinormal modes, and I will highlight several interesting properties of their spectrum.**Abstract**

If you are interested in presenting your research in Oxford, please contact Jonas Probst.

For a list of **past talks** follow this link.

**Other seminars of interest:**

- A weekly updated list of talks related to string theory.
- A list of all seminars in the Physics Department, including the Theoretical Physics Colloquium and the Particles and Fields Seminar.