Paolo Di Vecchia (born October 29, 1942 in Terracina) is an Italian theoretical physicist who worked in the field of elementary particle physics, quantum field theory and string theory.
Di Vecchia graduated from the University of Rome with Bruno Touschek in 1966. As a post-doctoral researcher he worked at the Nuclear Research Center in Frascati (where a permanent position was offered to him) and spent two years at the Massachusetts Institute of Technology and CERN.
In 1974 he became Assistant Professor at the NORDITA in Copenhagen. In 1978 he came back for a year at CERN. In 1979 he became professor at the Free University of Berlin and from 1980 to 1986 he taught at the Bergische Universität Wuppertal. From 1986 he has been a professor at NORDITA. Since NORDITA moved to Stockholm he spent half of the time there and half of the time at the Niels Bohr Institute in Copenhagen.
In the 1970s Di Vecchia was one of the pioneers of string theory. Among other things, he formulated with Lars Brink and others the locally supersymmetric Lagrangian for fermionic strings (i.e. those with fermionic excitations, half-integer spin). Previously, the Nambu-Goto action had been known for the bosonic string and different groups tried to construct a fermionic action.
In 1972, along with Emilio Del Giudice and Sergio Fubini, he introduced the "DDF states" scheme (also known as the DDF construction), which is named by the initials of the three scientists.
Along with Stanley Deser and Bruno Zumino he formulated string theory as a two-dimensional analogue of the general theory of relativity.