Abstract: The interaction of quantum fields with classical backgrounds gives rise to a variety of fundamental effects. Here we will review some recent theoretical and experimental developments of quantum field theory in the presence of strong backgrounds, be them electromagnetic or gravitational, of relevance for example in the description of the early universe and in the presence of intense lasers. In this scenario, we will describe the prediction and current quest of effects such as birefringence and pair creation in extreme environments.
José Navarro-Salas