October 15, 1909–April 20, 1992
BY MAURICE JACOB
GIAN-CARLO WICK WAS A renowned theoretical physicist of this century. His name is explicitly attached to a very important theorem, the Wick theorem, which played a substantial role in the early perturbative use of quantum field theory. It quickly made its way to textbooks on particles and fields and found later a great use in nuclear and condensed matter physics. Gian-Carlo Wick's name is also associated with the Wick rotation, a theoretical technique using imaginary time, which had an notable impact on the development of fruitful relations between field theory and statistical mechanics.
Gian-Carlo Wick is also well known for the insight and clarity that he brought to several questions at a key time in their development, in particular in meson theory and in the many applications of symmetry principles in particle physics. There are also many properties that are not associated explicitly with his name simply because they have since become part of the common knowledge of physicists. Yet, they were first due to the clarity of his mind and to his sharp insight for physical phenomena. One may mention, for instance, the extension of the then new Fermi theory of beta decay to positron emission and also the relation be-