Abraham Klein (January 10, 1927 – January 20, 2003) was an American

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experime ...

. Klein received his B.A. from Brooklyn College in 1947, and his S.M. (1948) and Ph.D. (1950) degrees from

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

under

Julian Schwinger Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant ...

. In 1955, he became associate professor at the

University of Pennsylvania The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universitie ...

, achieving full professorship in 1958 and retiring in 1994. Klein studied models of collective behavior in finite many-body systems, especially in

nuclear physics Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the ...

, for example in

Boson In particle physics, a boson ( ) is a subatomic particle whose spin quantum number has an integer value (0,1,2 ...). Bosons form one of the two fundamental classes of subatomic particle, the other being fermions, which have odd half-integer spi ...

model and in an extension of the

Hartree–Fock method In computational physics and chemistry, the Hartree–Fock (HF) method is a method of approximation for the determination of the wave function and the energy of a quantum many-body system in a stationary state. The Hartree–Fock method often ...

with Robert Kerman (Kerman–Klein method). In the 1980s he occupied himself with, among other things, the

interacting boson model The interacting boson model (IBM) is a model in nuclear physics in which nucleons (protons or neutrons) pair up, essentially acting as a single particle with boson properties, with integral spin of 0, 2 or 4. It is sometimes known as the Interac ...

, and in the 1970s with quantum field theory in strong fields (with

Johann Rafelski Johann Rafelski (born 19 May 1950) is a German-American theoretical physicist. He is professor of Physics at The University of Arizona in Tucson, guest scientist at CERN ( Geneva), and has been LMU-Excellent Guest Professor at the Ludwig Maxi ...

). In 1964, Klein published an article about

spontaneous symmetry breaking Spontaneous symmetry breaking is a spontaneous process of symmetry breaking, by which a physical system in a symmetric state spontaneously ends up in an asymmetric state. In particular, it can describe systems where the equations of motion or ...

with his student Benjamin W. Lee and contributed to the appearance of

Higgs mechanism In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons. Without the Higgs mechanism, all bosons (one of the two classes of particles, the other be ...

. He was a

Sloan Fellow The Sloan Fellows program is the world's first mid-career and senior career master's degree in general management and leadership. It was initially supported by a grant from Alfred P. Sloan, the late CEO of General Motors, to his alma mater, MI ...

and

Guggenheim Fellow Guggenheim Fellowships are grants that have been awarded annually since by the John Simon Guggenheim Memorial Foundation to those "who have demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the a ...

, Honorary Doctor of

Goethe University of Frankfurt Goethe University (german: link=no, Johann Wolfgang Goethe-Universität Frankfurt am Main) is a university located in Frankfurt am Main, Germany. It was founded in 1914 as a citizens' university, which means it was founded and funded by the wealt ...

, and Alexander von Humboldt Senior Scientist. Klein was a Fellow of the American Physical Society. He was married and had two daughters.

Bibliography

External links

Obituary from UPenn Almanac
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References

{{DEFAULTSORT:Klein, Abraham 1927 births 2003 deaths Brooklyn College alumni Fellows of the American Academy of Arts and Sciences Harvard University alumni American nuclear physicists University of Pennsylvania faculty 20th-century American physicists American theoretical physicists