Holography Seminar
Time and place: Tue 2-4 pm, Seminar Room 501, DWB
Hilary Term 2014 Talks:
- 21/01/2014: Joe Bhaseen (King's College London): Universal Thermal Transport from Holography and Hydrodynamics
Abstract: We will discuss recent applications of holographic duality and hydrodynamics to strongly correlated systems far from equilibrium. In particular, we will argue that long-time energy transport in quantum critical systems occurs via a universal steady-state for any spatial dimensionality [1]. This is described by a Lorentz boosted thermal state. We determine the transport properties of this emergent steady state, including the average energy flow and its long-time fluctuations.
- 28/01/2014: Tomas Andrade (U. Durham) : A simple holographic model of momentum relaxation
Abstract: We consider a holographic model consisting of Einstein-Maxwell theory in (d+1) bulk spacetime dimensions with (d-1) massless scalar fields. Momentum relaxation is realised simply through spatially dependent sources for operators dual to the neutral scalars, which can be engineered so that the bulk stress tensor and resulting black brane geometry are homogeneous and isotropic. We analytically calculate the DC conductivity, which is finite. In the d=3 case, both the black hole geometry and shear-mode current-current correlators are those of a sector of massive gravity.
- 04/02/2014: John Estes (Imperial College, London): Holographic Entanglement Entropy for Interface/Defect CFTs
Material: SlidesAbstract: Entanglement entropy is a useful quantity for characterizing the degrees of freedom in a system. For systems with a dual gravitational description, the AdS/CFT correspondence provides an efficient method for computing entanglement entropy analytically. In this talk I will discuss a generalization of holographic entanglement entropy to systems which contain a conformal defect, interface or boundary. We identify a cutoff independent term in the entanglement entropy, which characterizes the defect/boundary degrees of freedom. This generalizes the concept of boundary or defect entropy in 1+1-dimensions to higher dimensional systems.
- 10/02/2014: Additional seminar (Mo 5-7pm, 501 DWB): Stefan Stricker (Tech. U. Vienna): Holographic Thermalization at Intermediate Coupling
Material: Slides
- 11/02/2014: Alejandra Castro (U. Amsterdam): Holographic Entanglement Entropy in the Presence of Gravitational Anomalies
Abstract: In this talk I'll discuss the generalization of the Ryu-Takayanagi formula for entanglement entropy in the presence of gravitational anomalies in AdS_3/CFT_2. The three dimensional theory includes a gravitational Chern-Simons term which induces a Lorentz anomaly, and hence the dual CFT is characterized by unequal left and right moving central charges. We will independently derive the CFT and gravitational results, and find non-trivial agreement.
- 18/02/2014: Ioannis Papadimitriou (Madrid IFT): Non-Relativistic Holography for General z>1
- 25/02/2014: Nele Callebaut (U. Ghent): A Magnetic Instability of the Sakai-Sugimoto Model
Abstract: In the presence of strong magnetic fields, the QCD vacuum may become unstable towards condensation of charged rho mesons, forming a superconducting state. I will talk about our investigation of this possible instability in a well-known holographic QCD model called the Sakai-Sugimoto model. Rho meson condensation occurs in this model at very high values of the magnetic field, possibly present during the cosmological electroweak phase transition or in heavy ion collisions at the LHC.
- 04/03/2014: Shira Chapman (U. Tel-Aviv): Superfluid Hydrodynamics, Thermal Partition Function and Lifshitz Scaling
Abstract: We will review the basics of superfluidity, and discuss how quantum anomalies are manifested in superfluid hydrodynamics. We will present an algebraic method to derive Kubo formulas for the anomalous transport coefficients using the equilibrium partition function. We will outline the special features revealed in superfluid hydrodynamics, when it exhibits a Lifshitz scaling symmetry. Such a scaling is expected to hold in the quantum critical regime, and is potentially the underlying reason for the exotic properties of heavy fermions compounds and high T_c superconductors. We will discuss possible experimental signatures.
- 11/03/2014: Karl Landsteiner (Universidad Autonoma de Madrid): Quantum Anomalies and Non-Dissipative Transport
Material: NotesAbstract: Quantum anomalies belong to the most characteristic properties of of the quantum field theory of relativistc fermions. In the recent years it has become clear that anomalies are responsible for non-dissipative transport phenomena, such as the chiral magnetic and chiral vortical effect. I will review these developments and sketch possible applications in high energy and condensed matter physics.
If you are interested in presenting your research in Oxford, please contact Jonas Probst.
The following might also be 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.