QUANTUM FIELDS IN GRAVITY, COSMOLOGY AND BLACK HOLES

The research area of this project regards the fundamental gravitational interaction and the theoretical study of cosmology and black holes. In our framework, both quantum field theory (QFT) and gravity play essential roles. In the lack of a fully quantum theory of all interactions including gravity, QFT on curved space-time - where quantum fields describing matter and radiation interact with the non-quantised gravitational field - has historically proved to be a very successful approach. It has produced some of the most significant theoretical predictions of the last 40 years, such as black hole evaporation and the inflationary paradigm. The latter is now supported by observational data and plays the role of the standard model of cosmology. Moreover, there is increasing evidence that theoretical descriptions of (quantum) gravity may be consistently formulated by employing advanced QFT methods, such as those relying on generalised uncertainty principles, effective actions and the renormalisation group. The paradigms of asymptotic safety, classicalization and possible UV-completeness, or non-perturbative renormalizability, suggest that nowadays, a QFT formulation of gravity may therefore become predictive. The above scenarios have gained considerable attention and provide alternative routes to a fully consistent formulation of quantum gravity. We wish to employ these ideas to tackle the long-standing problems of the fate of classical singularities, as well as the physics of quantum matter in the presence of (dynamical) horizons, in cosmology and black holes, also including modified gravity theories.