Curved Spacetimes, Accelerated Frames and Quantum Theory

Abstract: I briefly present the baselines of Quantum Field Theory in  Curved Spacetimes (QFTCS), which investigates the consequences of defining a quantum field theory for the matter and its interactions  in a curved spacetime background described by General Relativity. Although being na effective theory, QFTCS allows the prediction of quantum  gravity effects, like thermal evaporation of black holes, known as the Hawking effect. Using the framework of QFTCS, one can also reexamine relevant  conceptual issues in Physics such as particle production (e. g. in an expanding universe), equivalence principle, etc. Indeed, after the first  developments in QFTCS, the particle concept itself has been revisited, from the point of view of different observers, leading to the Unruh effect, which  states that the Minkowski vacuum, identified with the absence of real particles according to inertial observers, manifests itself as a thermal bath  of real (Rindler) particles to uniformly accelerated observers. In this context, we analyze the radiation emitted by accelerated sources from the  point of view of co-accelerated observers and examples of how the presence of boundaries may influence radiation emission processes.  QFTCS allows also to obtain corrections due to spacetime curvature in quantum phenomena occurring near black holes and relativistic  stars. As particular examples, we comment on radiation  emission processes of sources and charges rotating around  black holes, and exhibit results obtained for absorption and  scattering cross sections for Schwarzschild and Reissner-Nordström black holes, as well as for acoustic analogues of black holes.