FLAG - Fields and Gravity

The research activity of the FLAG group in Trento mainly concerns with the investigation of important aspects of fundamental interactions, both from the mathematical and the physical point of view. Most activities are dedicated to the gravitational interaction, which governs the physics of all macroscopic objects in the world, like galaxies and black holes, but at the same time it governs the birth, the evolution and the ultimate fate of our universe.

The Science

In the original theory, inflation is driven by a suitable new scalar field (the inflaton), but it would be desirable to have a model in which the role of inflaton is played by the Higgs' field or alternatively a pure gravitational model that gives rise to inflation at high energy. Of course, in the latter case one has to consider modifications of Einstein's theory of gravity. Using modified gravity one can also obtain the observed actual accelerated expansion and so, in principle, one could explain both inflation and dark energy with the same model.

In the last few years, some theoretical predictions of physical cosmology regarding the evolution of the universe have been confirmed by observation, in particular the abundance with relative ratios of light elements and the existence of a cosmic microwave background (CMB) at temperature ~3K. These predictions are considered a strong evidence of the inflationary birth of our Universe. Nowadays, cosmology has entered an era of precise measurements, in particular of the CMB features and of the large scale structures. Therefore, for the first time in the history of science, we have the opportunity to test theories at energy scales and distances that are not reachable in a laboratory.

In this very exciting context, we are working in several aspects concerning inflation, dark energy, black holes physics and the interface between gravity and quantum field theory. The specific lines of research are:

- Inflationary theories and the vacuum energy, treated as distinct topics.
- Aspects of inflation related to broken scale invariance and the vacuum energy seen from the viewpoint of conformal field theories in Friedmann-Lemaître-Robertson-Walker spaces.
- Scale invariant gravity: classical solutions and quantum corrections.
- Dark energy as a Yang-Mills Higgs theory.
- Dark energy studies in collaboration with the Euclid Theory Working Group (ESA Mission to be launched in 2020)
- Spherically symmetric solutions with matter in Galileon-like theories.
- Analogue models of gravity in condensed matter systems.
- Inflation in modified gravity: contributions due to one-loop quantum corrections to the slow-roll parameters.
- Physics of black holes.
- Mathematical aspects of quantum fields in the presence of gravitation, using local algebraic methods.


• Involved external institutions: University of Mons (Belgium), University of Namur (Belgium), University of Austral Chile, Shangai Normal University (China), Hamburg University (Germany), Università di Genova (Italy), Università di Pavia (Italy), University of Nagoya (Japan), Ochanomizu University (Japan), Eurasian National University, Astana (Kazakistan), CSICC-CICYT, Barcelona (Spain), ICREA, Barcelona (Spain)
• INFN groups: Bologna, TIFPA, Trieste, Milano
• Principal Investigator: Roberto Casadio (INFN Bologna)
• INFN Project: CSN IV
• Duration: n/a


• Local responsible for TIFPA: Luciano Vanzo
• Involved TIFPA people: Sergio Zerbini, Massimiliano Rinaldi, Evgenia Rabochaya, Stefano Chinaglia. Aymeric Colleaux, Marco Calza, Giovanni Tambalo



The Origin of Universe


Black Hole