Virginia and Maryland String and Particle Theory Meeting
University of Virginia
March 31, 2012
Physics Room 204
Vijay Balasubramanian (University of Pennsylvania)
"Momentum space entanglement and renormalization in quantum field theory"
The degrees of freedom of any interacting quantum field theory are entangled in momentum space. Thus, in the vacuum state, the infrared degrees of freedom are described by a density matrix with an entanglement entropy. We derive a relation between this density matrix and a Wilsonian effective action. We argue that the entanglement entropy of and mutual information between subsets of field theoretic degrees of freedom at different momentum scales are natural observables in quantum field theory and demonstrate how to compute these in perturbation theory. The results may be understood heuristically based on the scale-dependence of the coupling strength and number of degrees of freedom. We measure the rate at which entanglement between degrees of freedom declines as their scales separate and suggest that this decay is related to the property of decoupling in quantum field theory.
Mirjam Cvetic (University of Pennsylvania)
"General Black Holes and Their Microscopics"
We review properties of multi-charged rotating black holes in asymptotically Minkowski and anti-deSitter space-times, as solutions of maximally supersymmetric compactifications of String Theory. We focus on recent progress in deriving the conformal invariance and the microscopics of general, asymptotically flat rotating black holes in four- and five-dimensions.
Dmitri Kharzeev (Brookhaven National Laboratory)
"The chiral magnetic effect and chiral hydrodynamics of relativistic plasmas"
The interplay of quantum anomalies, topology and magnetic field results in a number of surprising phenomena in relativistic plasmas. In particular, the chirality imbalance induces the separation of electric charge along the axis of magnetic field (the Chiral Magnetic Effect, CME). The existence of CME has been confirmed by the lattice QCDxQED computations, and there is an evidence for it from heavy ion experiments at RHIC and LHC. The CME current is non-dissipative, and persists in strongly coupled systems that admit hydrodynamical description. Quantum anomalies significantly affect the hydrodynamics of relativistic plasmas leading in particular to the emergence of novel gapless collective excitations. Apart from the quark-gluon plasma, the CME current and related phenomena can exist in chiral materials (e.g. graphene, topological insulators, and Weyl semi-metals).
Paul Langacker (Institute for Advanced Study)
"New Physics from the String Vacuum"
Concrete semi-realistic string constructions often lead to predictions for low energy physics that are more complicated than the usual MSSM paradigm. These often include string remnants such as additional U(1)' gauge symmetries, extended quasi-chiral fermion sectors, and extended Higgs/neutralino sectors. Non-standard mechanisms for obtaining small Dirac or Majorana neutrino masses (or both) are another common occurence. Examples of such ``beyond the MSSM'' physics and their consequences will be discussed, mainly drawn from Type IIA quivers.