Microlensing is the amplification of the light of a background star due to the transit on the line of sight of a massive object, which acts as a gravitational lens. The lens can be another star or a brown dwarf. The light curve of the background star has a typical bell shape, with a duration of a few days. Since microlensing events are very rare, millions of source stars must be monitored every night in order to detect them. (didactic movie)

Microlensing can be used to search for extrasolar planets. In fact, if the lens is a star accompanied by a planet, the light curve of the source contains an anomaly like a secondary peak or a dip. We are members of the Microlensing Science Investigation Team for the mission WFIRST by NASA. Our group is part of the MiNDSTEp collaboration, observing from the Danish telescope at ESO, La Silla (Chile) and from Salerno University Observatory. We are members of the ROME-REA collaboration for source characterization.
We have also developed an advanced code for automatic real-time modeling of anomalous microlensing events (RTModel).
This is based on the publicly available software VBBinaryLensing for the calculation of microlensing light curves.

Extrasolar planets can also be found by their transits on the disk of the mother-star. Salerno University Observatory is part of the KELT-follow-up network and the TESS-follow-up group for candidate transit validation (see Nature paper on the discovery of KELT-9b).
We are also included in the Gaia follow-up group.
Side projects include quasar microlensing, variables in globular clusters, elliptic binaries.

Gravitational lensing by black holes leads to the spectacular formation of infinite sequences of images very close to the shadow cast by the black hole in the sky. The direct observation of this shadow has been recently achieved by the Event Horizon Telescope. The black hole in the center of our Galaxy provides the best candidate for new observations that are opening a new era in gravitational physics. (read more)

Early universe cosmology investigates the first instants of our universe. General Relativity is not sufficient to describe the hot quantum universe close to the big bang. String theory and other quantum gravity theories suggest the possibility that the big bang was actually not the beginning of time, but just a transition from a previous pre-big bang collapsing universe to our observed expanding universe.

The Baryon Asymmetry problem refers to the observed asymmetry in the Universe between baryonic and antibaryonic matter. Since the Big Bang should have produced equal amounts of matter and antimatter, it is then expected that some still unkonw mechanism must have acted differently for matter and antimatter during the Universe evolution. This mechanism cannot be explaind within the standard model of particle physics and cosmology, and in fact, modern theories aimed at solving the problem of the baryon asymmetry are based on physics beyond these models.