We discuss gedanken
experiments for measuring local and non-local observables in QFT that
respect causality, and can by used to test the entanglement between two spatially distant regions in the vacuum. It is shown that the entanglement
decays exponentially with the distance between the regions and does not vanish, in contrast to the
case of lattice models. We discuss in this respect a possible mechanism which might
explain this persistence effect, and a connection between the Reeh-Schlieder
theorem and superoscillations.
This talk aims to review the obstacles met in QFT to
reach an appropriate definition for such a basic concept as localization. The
anti-local character of the square root of the "- Laplace-Beltrami +
mass^2" operator prevents the existence of localized states with a finite
number of quanta. (Bosonic) quantum fields describe elementary excitations of
an extended system whose ground state is the vacuum. No wonder, there is a
complicated relationship between the cardinal
(quantal) and continuous (spatial) sides of the theory.
We will also analyze the roles (if any) played in RQI by the localized
excitations of the vacuum.
I will describe numerical simulations of quenches in AdS-CMT superconductors where we are able to construct a dynamical phase diagram for the system. I will describe how the late time behaviour is understood in terms of the quasinormal modes of the system, and how a rather generic behaviour of the pole structure there leads to interesting physical consequences that have an analog in condensed matter calculations using integrable models.
In the context of the possible existence of large extra dimensions, and also the context of the AdS-CFT correspondence, there has been much interest in black holes solutions in theories of gravity and matter that are exotic - they might live in spacetime dimension other than 4, or have exotic matter and boundary conditions. I will review the types of physics that are accessible by studying such exotic black holes, ranging from LHC phenomenology to potential applications to condensed matter physics (via the AdS-CFT correspondence). One common theme is that traditional analytic methods to find solutions tend not to work when confronted with these more exotic solutions and instead we are increasingly forced to use numerical techniques. I will discuss a numerical approach to finding static and stationary solutions, and give some example applications. I will also show how dynamical numerical simulations in these exotic contexts are playing an increasingly important role.
Instituto Superior Tecnico - Departamento de Física
PIRSA:12060012
Superradiance in black hole physics is responsible for a chief number of
interesting and spectacular effects. Here I will discuss some attempts
at understanding the behavior of massive bosonic fields around rotating
black holes, with focus on superradiance.