# Research | Fisica teorica delle interazioni fondamentali

## Research Fisica teorica delle interazioni fondamentali

**Quantum mechanics and quantum information**

Quantum mechanics is essentially based on a probabilistic conception of particles, but a recent proposal put forward by G. 't Hooft foreshadows the possibility of obtaining quantum mechanics as the low-energy limit of a completely deterministic theory. Another interesting aspect is given by geometric phases and invariants, which we analyze in different systems (neutrinos, axions, Hawking-Unruh effect, interferometry) in order to test the fundamental symmetries of nature. Finally, we are interested both in the study of the general properties of quantum correlations (entanglement, discord, etc.) and in applications. In particular, we first highlighted the single-particle entanglement properties associated with neutrino oscillations.

**Quantum field theory**

A distinctive aspect of quantum field theory, compared to quantum mechanics, is represented by the presence of unitarily inequivalent representations, connected to the existence in QFT of several physically distinct vacua. On this basis, the group is active in the treatment with methods of quantum field theory of problems in elementary particles physics (mixing and oscillations of neutrinos and mesons), of quantum systems at finite temperature and with topological defects, of field theory in curved space-times, up to the modeling of biological systems.

**Dark energy and dark matter**

Recent studies conducted by the group show that the condensates induced by different systems contribute to the energy of the vacuum and have a behavior similar to that of the dark matter and dark energy of the universe. The formal analogy between systems characterized by condensates can open up new scenarios in the possibility of detecting the components of the dark energy and dark matter of the universe in experiments conducted in the laboratory. Extremely revealing for the understanding of dark matter and dark energy are extended theories of gravity that represent an extension of General Relativity.

**Gravitational waves**

The discovery of gravitational waves has opened a new era of modern physics, both theoretical and experimental, and is allowing us to investigate and understand some aspects of the evolution of the Universe, from the early stages to the dark age. This study includes black holes, compact objects, dark matter, and dark energy, as well as particles predicted by theories that extend the Standard Model. In this context, we participate in the international collaborations LISA and Einstein Telescope.