Semigroups, Evolution Equations and Positivity

The workshop “Semigroups, Evolution Equations and Positivity” on the occasion of Rainer Nagel’s 85th birthday has been held at the University of Siena in December 3-5, 2025.

The Italian-German collaboration in the field of functional analysis—with a particular focus on evolution equations, operator semigroups, and positivity—was initiated by Edoardo Vesentini and Giuseppe Da Prato in Pisa, and by Helmut H. Schaefer and Rainer Nagel in Tübingen. The aim of this workshop is to celebrate this long-standing partnership, tracing its development from classical results to recent advances and open problems.

The workshop seeks to enhance the understanding of semigroup theory among young researchers, providing both educational and networking opportunities.