Gunnar Källén
Encyclopedia
Gunnar Källén, born February 13, 1926 in Kristianstad
, Sweden
and died October 13, 1968 in Hannover, Germany
in a plane accident. Källén was a leading Swedish theoretical physicist and a professor at Lund University
until his death at the age of 42.
Källén earned his doctorate at Lund in 1950 and worked between 1952 and 1958 at CERN
's theoretical division, which then became the Niels Bohr Institute
in Copenhagen. He also worked at Nordita 1957-1958 and then began a professorship at Lund University.
Källén's research focused on quantum field theory
and elementary particle
physics. His developments included the so-called Källén–Lehmann representation
of correlation functions in quantum field theory, and he made contributions to quantum electrodynamics
, especially in renormalizing. He also worked with the axiomatic formulation of quantum field theory, which led to contributions to the theory of functions of several complex variables. He collaborated on the Pauli-Källén equation. The function
which appears in kinematical equations is called the Källén function.
Källén worked for several years at the Bohr Institute. Källén was flying his own plane from CERN in Geneva
when it crashed in 1968. His two passengers, one of them his wife, survived the crash.
Kristianstad
Kristianstad is a city and the seat of Kristianstad Municipality, Skåne County, Sweden with 35,711 inhabitants in 2010.-History:The city was founded in 1614 by King Christian IV of Denmark, the city's name literally means 'Town of Christian', as a planned city after the burning of the town of Vä...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
and died October 13, 1968 in Hannover, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
in a plane accident. Källén was a leading Swedish theoretical physicist and a professor at Lund University
Lund University
Lund University , located in the city of Lund in the province of Scania, Sweden, is one of northern Europe's most prestigious universities and one of Scandinavia's largest institutions for education and research, frequently ranked among the world's top 100 universities...
until his death at the age of 42.
Källén earned his doctorate at Lund in 1950 and worked between 1952 and 1958 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...
's theoretical division, which then became the Niels Bohr Institute
Niels Bohr Institute
The Niels Bohr Institute is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics....
in Copenhagen. He also worked at Nordita 1957-1958 and then began a professorship at Lund University.
Källén's research focused on 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...
and elementary particle
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
physics. His developments included the so-called Källén–Lehmann representation
Källén-Lehmann spectral representation
Källén-Lehmann spectral representation gives a general expression for the two-point function of an interacting quantum field theory as a sum of free propagators. It was discovered by Gunnar Källén and Harry Lehmann independently...
of correlation functions in quantum field theory, and he made contributions to quantum electrodynamics
Quantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
, especially in renormalizing. He also worked with the axiomatic formulation of quantum field theory, which led to contributions to the theory of functions of several complex variables. He collaborated on the Pauli-Källén equation. The function
which appears in kinematical equations is called the Källén function.Källén worked for several years at the Bohr Institute. Källén was flying his own plane from CERN 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...
when it crashed in 1968. His two passengers, one of them his wife, survived the crash.