​Daniele Angella graduated in Mathematics at Università di Parma, and obtained his Ph.D. in Mathematics at Università di Pisa in 2013. He was a postdoc at INdAM and junior visiting fellow at Centro di Ricerca Matematica "Ennio de Giorgi" in Pisa. He is now a researcher at Università di Firenze. His research interests are in differential and complex geometry.Adriano Tomassini received his Ph.D. in Mathematics at the University of Forence in 1997. He was assistant professor at the University of Palermo and then at the University of Parma, where he is currently professor of geometry. He has visited the Universities of Michigan, Minnesota, Notre Dame and Stanford. His research interests are in complex, symplectic and differential geometry. He is the author of around 55 publications. Costantino Medori received his Ph.D. in Mathematics at the International School for Advanced Studies (Trieste, Italy) in 1996. He was a postdoc at the University of Pisa and then a researcher at the University of Parma, where he is currently professor of geometry. His research interests are in differential and complex geometry, more specifically in CR geometry. He is the author of around 30 publications.