From Dirac to Nobel

ICTP Dirac Medallist Giorgio Parisi has received one-half of this year's Nobel Prize in Physics, sharing the award with two other laureates for their studies of chaotic and apparently random phenomena.

Parisi's Nobel Prize honours his "discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales", while his co-winners, Syukuro Manabe and Klaus Hasselmann, were cited "for the physical modelling of Earth's climate, quantifying variability and reliably predicting global warming".

The Nobel recognition follows on another prestigious award given to Parisi earlier this year: in February, he received the  Wolf Prize “for ground-breaking discoveries in disordered systems, particle physics and statistical physics”.

Parisi is a professor of theoretical physics at the University of Rome "La Sapienza", where his research has focused on quantum field theory, statistical mechanics, and complex systems.

He has strong connections with ICTP. In 1999, he won the Centre's Dirac Medal for his original and deep contributions to many areas of physics, and currently serves as a member of the distinguished selection committee for that Medal.

"Giorgio has had close ties with ICTP for many years and has important scientific collaborations with many members of the ICTP family," said ICTP Director Atish Dabholkar, adding, "This Nobel prize is cause for celebration for all of us in theoretical physics, but also for Italian science and for the ICTP family."

Director Dabholkar explained that in addition to the work cited by the Nobel committee, Parisi is well known for his ground-breaking contributions in quantum field  theory, statistical physics, and complex systems. "His deep and original insights have influenced research in wide-ranging topics all the way from the evolution equations for the constituents of nuclear matter in quantum chromodynamics to disordered systems from the microscopic to the macroscopic scales, and spin glasses with their implications for the theory of computational complexity," said Dabholkar.

One of Parisi's close collaborators at ICTP is Antonello Scardicchio, a researcher in the Condensed Matter and Statistical Physics section. "A Nobel prize recognising the importance of the growing field of complex systems could not have been more timely, and could not have been awarded to a more deserving scientist than Giorgio Parisi," said Scardicchio, who has co-authored papers with Parisi.

Reflecting on the collaboration with the Nobel Laureate, Scardicchio explained, "Giorgio’s interest in (and knowledge of) physics has no boundaries, and in working with him you know on which topic you start the collaboration but not in which one you are going to end up writing the paper. A collaboration on random matrices can end up being a series of papers on the properties of quantum entanglement; a work which started on entanglement can bear results on classifying human languages."

"Giorgio’s contributions to the shaping and organization of our knowledge of the Physics of complex systems, ranging from disordered, microscopic quantum spins to the fly of a flock of birds, are unprecedented," added Scardicchio.