His scientific activity is essentially devoted to General Relativity, Cosmology and Relativistic Astrophysics in their theoretical and phenomenological aspects.
His main scientific achievement is related to the possibility to explain dark energy and dark matter as curvature effects by extending General Relativity to more general classes of theories of gravity. Furthermore, he developed the so-called Noether Symmetry Approach to identify and solve dynamical systems representing cosmological models. A further field of interest is the astrophysics of compact objects (neutron stars and black holes) and gravitational waves with the aim to identify observational signatures for Modified Gravity. The results of these researches are published in more than 650 papers appeared in several refereed journals with more than 52000 citations. He is also author of monographic texts on General Relativity, Cosmology, Quantum Mechanics and Noether symmetries (Eds. Springer, Cambridge, Bibliopolis, Liguori).
He has been supervisor of almost 50 PhD and 70 Master Italian and foreign students in Physics and Mathematics. He spent several periods of his scientific career in USA, Germany, Poland, UK, Russia, South Africa, Canada, Brazil and Japan .He is in the World's Top 2% Scientists at Stanford University. In 2024, he resulted among the Top 10 Italian Scientists.