Gravitation and Cosmology

Energy-scale systems typical for astrophysics and cosmology have long been studied in the semiclassical approach in which General Relativity describes gravity while matter is described by quantum field theories. From here, classical effective descriptions and fully quantum models are developed for:

Gravitational interactions: effective theories of low-energy and modified gravity; quantization by coherent states; quantum field theories on curved space and analogies with condensed state models; ultraviolet completeness and existence of minimum length scales; thermodynamics of scalar-tensor theories.

Theoretical cosmology: models of cosmological inflation and cosmic microwave background radiation; dark energy models, theories of modified gravity and dark matter; quantum cosmology and the study of cosmological singularities, with applications to inflation, reheating, matter, dark radiation and energy, and the production of primordial black holes. 

Physics of black holes and compact astrophysical objects: quantum models and effects for high-compactness self-gravitating systems; gravitational collapse and formation of horizons with Hawking radiation; resolution of classical singularities and regular quantum black holes; exotic astrophysical objects and compact sources in quantum and post-Newtonian gravitation; perturbations and emission of gravitational waves.

Faculty members: Roberto Casadio, Andrea Giusti, Alexandr Kamenchtchik, Francisco Manuel Soares Verissimo Gil Pedro, Alessandro Tronconi

Research activities

Quantum field theories of gravity

This line of research aims at investigating the fundamental gravitational interaction at length and energy scales where quantum effects cannot be neglected. Various approaches are followed, such as: i) Low-energy effective field theories, ii) Ultra-violet completion, renormalization group flow and Asymptotic Safety , iii) Modified gravity theories, non-linear Newtonian and corpuscular models;  iv) Quantum field theories on curved backgrounds and analogue solid state models; v) Quantum gravity aspects related with a minimum measurable length and the statistical interpretation of the gravitational field equations.

Theoretical cosmology

The entire Universe evolution is studied, from the early instants of time after the Big Bang to the present accelerating era: i) models of inflationary cosmology and cosmic microwave background radiation; ii)  Models of dark energy, modified gravity theories and dark matter; iii) Quantum cosmology and the fate of cosmological singularities; iv) String cosmology with applications to cosmological inflation, reheating, dark matter, dark radiation and dark energy; v) Primordial black hole production. 

Physics of black holes and compact astrophysical objects

Gravitational interactions are investigated for physical systems in extreme configurations like black holes and other compact astrophysical objects: i) Analogue models for the Hawking radiation; ii) Horizon formation and onset of Hawking radiation in the gravitational collapse of compact objects, the possible removal of classical singularities and regular black holes; iii) Minimal Geometric Deformation for exotic compact astrophysical objects and compact sources in post-Newtonian quantum gravity.

Collaborations