My research activity is focused on the theoretical study of open quantum systems, namely systems whose dynamics is influenced by an external environment. This theory is inherently related to the foundations of quantum mechanics, indeed measure theory just faces the description of the interaction between the relevant system and a macroscopic measurement apparatus. A crucial aspect of the theory of open quantum systems, namely decoherence, has helped in better understanding the features of quantum measurement processes. The reduced dynamics of an open quantum system is typically irreversible and calls for time evolutions more general than unitary ones, described by so-called quantum dynamical maps. 
Within this field I devoted my activity to the microscopic derivation, the mathematical characterization and the study of memory properties, namely the so called Markovianity, of such quantum dynamical maps.  I have recently proposed and contributed to the realization of experiments on the non-Markovianity dynamics and on the relevance of initial system-environment correlations.
This research activity on open quantum systems has led me to teach a course on Open quantum system theory for master students.

Main results:

Quantum divergences for the study of distinguishability
[see in particular: N. Megier, A. Smirne and B. Vacchini Phys. Rev. Lett. 127, 030401 (2021)]

Collisional models
[see in particular: S. Campbell and B. Vacchini EPL 133, 60001 (2021)]

General characterization of non-Markovian open quantum system dynamics
[see in particular: H.-P. Breuer, E.-M. Laine, J. Piilo, and B. Vacchini Rev. Mod. Phys. 88, 021002 (2016)]

General characterization of non-Markovian completely positive master equations
[see in particular: B. Vacchini Phys. Rev. Lett. 117, 230401 (2016)]

Derivation of the quantum version of the linear Boltzmann equation for the description of dissipation and decoherence
[see in particular: B. Vacchini and K. Hornberger Phys. Rep. 478, pp. 71-120 (2009)]

General characterization of translation-covariant master equations and their connection to Lévy processes
[see in particular: B. Vacchini Phys. Rev. Lett. 95, 230402 (2005)]

Microscopic derivation of completely positive master equation for the description of quantum Brownian motion
[see in particular: B. Vacchini Phys. Rev. Lett. 84, pp. 1374-1377 (2000)]