In relativistic quantum information (RQI) we study quantum information in relativistic systems to obtain more insights to both quantum and gravitational physics on the one hand, and to find new ideas for quantum information processing on the other. One of the popular models in RQI is the Unruh-DeWitt (UD) detector theory, in which localized objects, called detectors, are coupled to and moving in relativistc quantum fields. In this mini-course I will discuss the UD detector theory in detail, mainly on the nonperturbative methods and their applications to RQI.
In these lectures, we will study the bosonic theory of higher-spin gravity in four dimensions. After discussing the reasons for interest in the theory, we will focus on the equations of motion and their content. We will aim to construct the equations from the ground up in a motivated way. The logical order will differ somewhat from standard introductions. As preliminaries, we will discuss the geometry of spinors and twistors in (anti) de Sitter space, along with various viewpoints on free massless fields with arbitrary spin. An ulterior goal of the lectures is to introduce a new version of the theory (arXiv:1502.06685), formulated on a fixed (A)dS background.