Gian-Carlo Wick
Encyclopedia
Gian Carlo Wick was an Italian
theoretical physicist who made important contributions to quantum field theory
. The Wick rotation
, Wick contraction, Wick's theorem
, and the Wick product
are named after him.
to Italy and his grandmother from Austria
. In 1930 he received his degree in Turin
under G. Wataghin with a thesis on the electronic theory of metals, and then went to Göttingen
and Leipzig
to study physics. One of the professors he got to know there was Werner Heisenberg
. Heisenberg liked the young Italian theoretician-they shared a common interest in classic music- and treated him with an affection that Wick never forgot. Once a week, Heisenberg had invited Wick and other students to his home for spirited evenings of talk and Ping-Pong. Back in Turin, he became Enrico Fermi
's assistant in Rome in 1932. In 1937 he became professor of theoretical physics in Palermo
, then in Padua
, before, in 1940, he returned to Rome and became chair of theoretical physics. In 1946 he followed Fermi to the United States
, first to the University of Notre Dame
, then to Berkeley
. Since he refused a required oath during the McCarthy era
(he had inherited strong liberal views from his mother), he went to the Carnegie Institute of Technology
in Pittsburgh in 1951, where he remained until 1957, interrupted by stays at the Institute for Advanced Study
in Princeton
and at CERN
in Geneva
. In 1957 he became chief of the theory department at Brookhaven National Laboratory. In 1965 he became a tenured professor at Columbia University
in New York City
, where he collaborated with Tsung-Dao Lee
; after his retirement from Columbia he worked at the Scuola Normale Superiore in Pisa.
In 1967 he received the Dannie Heineman Prize. In 1968 he received the first Ettore Majorana Prize. He was a member of the United States National Academy of Sciences
and the Accademia dei Lincei
.
Wick was an avid mountain climber. He was twice married and had two sons.
particle. He also worked on slowing down of neutrons in matter, and joined a group of Italian physicists led by Gilberto Bernardini which made the first measurement of the lifetime of the muon
.
While in the United States, Wick made fundamental contributions to quantum field theory, such as the Wick theorem in 1950, which showed how to express calculations in quantum field theory in terms of normally-ordered products and thus derive Feynman rules. He also introduced the Wick rotation
, in which computations are analytically continued from Minkowski space
to four-dimensional Euclidean space
. He developed the helicity formulation for collisions between particles with arbitrary spin, worked with Geoffrey Chew on the impulse approximation, and worked on meson theory, symmetry principles in physics, and the vacuum structure of quantum field theory.
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
theoretical physicist who made important contributions to quantum field theory
Quantum field theory
Quantum field theory provides a theoretical framework for constructing quantum mechanical models of systems classically parametrized by an infinite number of dynamical degrees of freedom, that is, fields and many-body systems. It is the natural and quantitative language of particle physics and...
. The Wick rotation
Wick rotation
In physics, Wick rotation, named after Gian-Carlo Wick, is a method of finding a solution to a mathematical problem in Minkowski space from a solution to a related problem in Euclidean space by means of a transformation that substitutes an imaginary-number variable for a real-number variable...
, Wick contraction, Wick's theorem
Wick's theorem
Wick's theorem is a method of reducing high-order derivatives to a combinatorics problem . It is named after Gian-Carlo Wick. It is used extensively in quantum field theory to reduce arbitrary products of creation and annihilation operators to sums of products of pairs of these operators...
, and the Wick product
Wick product
In probability theory, the Wick product\langle X_1,\dots,X_k \rangle\,named after physicist Gian-Carlo Wick, is a sort of product of the random variables, X1, ..., Xk, defined recursively as follows:\langle \rangle = 1\,...
are named after him.
Life
Wick's father was a chemical engineer, and his mother, Barbara Allason (1877-1968), was a well-known Italian writer and anti-fascist. His paternal grandfather had emigrated from SwitzerlandSwitzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
to Italy and his grandmother from Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
. In 1930 he received his degree in Turin
Turin
Turin is a city and major business and cultural centre in northern Italy, capital of the Piedmont region, located mainly on the left bank of the Po River and surrounded by the Alpine arch. The population of the city proper is 909,193 while the population of the urban area is estimated by Eurostat...
under G. Wataghin with a thesis on the electronic theory of metals, and then went to Göttingen
Göttingen
Göttingen is a university town in Lower Saxony, Germany. It is the capital of the district of Göttingen. The Leine river runs through the town. In 2006 the population was 129,686.-General information:...
and Leipzig
Leipzig
Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...
to study physics. One of the professors he got to know there was Werner Heisenberg
Werner Heisenberg
Werner Karl Heisenberg was a German theoretical physicist who made foundational contributions to quantum mechanics and is best known for asserting the uncertainty principle of quantum theory...
. Heisenberg liked the young Italian theoretician-they shared a common interest in classic music- and treated him with an affection that Wick never forgot. Once a week, Heisenberg had invited Wick and other students to his home for spirited evenings of talk and Ping-Pong. Back in Turin, he became Enrico Fermi
Enrico Fermi
Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...
's assistant in Rome in 1932. In 1937 he became professor of theoretical physics in Palermo
Palermo
Palermo is a city in Southern Italy, the capital of both the autonomous region of Sicily and the Province of Palermo. The city is noted for its history, culture, architecture and gastronomy, playing an important role throughout much of its existence; it is over 2,700 years old...
, then in Padua
Padua
Padua is a city and comune in the Veneto, northern Italy. It is the capital of the province of Padua and the economic and communications hub of the area. Padua's population is 212,500 . The city is sometimes included, with Venice and Treviso, in the Padua-Treviso-Venice Metropolitan Area, having...
, before, in 1940, he returned to Rome and became chair of theoretical physics. In 1946 he followed Fermi to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, first to the University of Notre Dame
University of Notre Dame
The University of Notre Dame du Lac is a Catholic research university located in Notre Dame, an unincorporated community north of the city of South Bend, in St. Joseph County, Indiana, United States...
, then to Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
. Since he refused a required oath during the McCarthy era
McCarthyism
McCarthyism is the practice of making accusations of disloyalty, subversion, or treason without proper regard for evidence. The term has its origins in the period in the United States known as the Second Red Scare, lasting roughly from the late 1940s to the late 1950s and characterized by...
(he had inherited strong liberal views from his mother), he went to the Carnegie Institute of Technology
Carnegie Institute of Technology
The Carnegie Institute of Technology , is the name for Carnegie Mellon University’s College of Engineering. It was first called the Carnegie Technical Schools, or Carnegie Tech, when it was founded in 1900 by Andrew Carnegie who intended to build a “first class technical school” in Pittsburgh,...
in Pittsburgh in 1951, where he remained until 1957, interrupted by stays at the Institute for Advanced Study
Institute for Advanced Study
The Institute for Advanced Study, located in Princeton, New Jersey, United States, is an independent postgraduate center for theoretical research and intellectual inquiry. It was founded in 1930 by Abraham Flexner...
in Princeton
Princeton, New Jersey
Princeton is a community located in Mercer County, New Jersey, United States. It is best known as the location of Princeton University, which has been sited in the community since 1756...
and at CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
in Geneva
Geneva
Geneva In the national languages of Switzerland the city is known as Genf , Ginevra and Genevra is the second-most-populous city in Switzerland and is the most populous city of Romandie, the French-speaking part of Switzerland...
. In 1957 he became chief of the theory department at Brookhaven National Laboratory. In 1965 he became a tenured professor at Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
, where he collaborated with Tsung-Dao Lee
Tsung-Dao Lee
Tsung-Dao Lee is a Chinese born-American physicist, well known for his work on parity violation, the Lee Model, particle physics, relativistic heavy ion physics, nontopological solitons and soliton stars....
; after his retirement from Columbia he worked at the Scuola Normale Superiore in Pisa.
In 1967 he received the Dannie Heineman Prize. In 1968 he received the first Ettore Majorana Prize. He was a member of the United States National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
and the Accademia dei Lincei
Accademia dei Lincei
The Accademia dei Lincei, , is an Italian science academy, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy....
.
Wick was an avid mountain climber. He was twice married and had two sons.
Work
As a member of Fermi's group in Rome, Wick calculated the magnetic moment of the hydrogen molecule with group-theoretical methods. He extended Fermi's theory of beta decay to positron emission and K-capture, and explained the relationship between the range of a force and the mass of its force carrierForce carrier
In particle physics, quantum field theories such as the Standard Model describe nature in terms of fields. Each field has a complementary description as the set of particles of a particular type...
particle. He also worked on slowing down of neutrons in matter, and joined a group of Italian physicists led by Gilberto Bernardini which made the first measurement of the lifetime of the muon
Muon
The muon |mu]] used to represent it) is an elementary particle similar to the electron, with a unitary negative electric charge and a spin of ½. Together with the electron, the tau, and the three neutrinos, it is classified as a lepton...
.
While in the United States, Wick made fundamental contributions to quantum field theory, such as the Wick theorem in 1950, which showed how to express calculations in quantum field theory in terms of normally-ordered products and thus derive Feynman rules. He also introduced the Wick rotation
Wick rotation
In physics, Wick rotation, named after Gian-Carlo Wick, is a method of finding a solution to a mathematical problem in Minkowski space from a solution to a related problem in Euclidean space by means of a transformation that substitutes an imaginary-number variable for a real-number variable...
, in which computations are analytically continued from Minkowski space
Minkowski space
In physics and mathematics, Minkowski space or Minkowski spacetime is the mathematical setting in which Einstein's theory of special relativity is most conveniently formulated...
to four-dimensional Euclidean space
Euclidean space
In mathematics, Euclidean space is the Euclidean plane and three-dimensional space of Euclidean geometry, as well as the generalizations of these notions to higher dimensions...
. He developed the helicity formulation for collisions between particles with arbitrary spin, worked with Geoffrey Chew on the impulse approximation, and worked on meson theory, symmetry principles in physics, and the vacuum structure of quantum field theory.
Selected bibliography
- Über die Wechselwirkung zwischen Neutronen und Protonen, Zeitschrift für Physik 84, #11–12 (1933), pp. 799–800, .
- The Evaluation of the Collision Matrix, Physical Review 80 (1950), pp. 268–272, .
- Properties of Bethe-Salpeter Wave Functions, Physical Review 96 (1954), pp. 1124–1134, (introduced the Wick rotation.)
- Introduction to Some Recent Work in Meson Theory, Reviews of Modern Physics 27 (1955), pp. 339–362, .
- (with Maurice Jacob) On the general theory of collisions for particles with spin, Annals of Physics 7, #4 (August 1959), pp. 404–428, .
- (with Arthur Strong Wightman and Eugene P. Wigner) Superselection Rule for Charge, Physical Review D 1 (1970), pp. 3267–3269, .
- (with Tsung-Dao LeeTsung-Dao LeeTsung-Dao Lee is a Chinese born-American physicist, well known for his work on parity violation, the Lee Model, particle physics, relativistic heavy ion physics, nontopological solitons and soliton stars....
) Vacuum stability and vacuum excitation in a spin-0 field theory, Physical Review D 9 (1974), pp. 2291–2316, .