EGD Cohen

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Ezekiel Godert David Cohen , cited as EGD Cohen, (born January 16, 1923 in Amsterdam , Netherlands ; † September 24, 2017 ) was an American theoretical physicist who dealt with statistical physics.

Live and act

Cohen studied in Amsterdam , where he received his doctorate under Jan Hendrik de Boer in 1957 (On the theory of the liquid state) and was a lecturer. He then spent two years as a postdoc in the USA at the University of Michigan in Ann Arbor with George Uhlenbeck and Theodore H. Berlin . From 1963 he was a professor at Rockefeller University in New York City , most recently as professor emeritus.

Cohen dealt, among other things, with the Boltzmann equation and the kinetic theory of dense gases and liquids. In the 1960s he and J. Robert Dorfman showed that an extension of the Boltzmann equation to gases of high density as a power series expansion in the density is not possible. His prediction of incomplete phase separation of liquid helium at low temperatures, which was later experimentally confirmed, led to the development of a new cooling principle for very low temperatures (helium dilution refrigerator).

From the 1990s he worked a. a. with lattice gases (where he discovered new types of diffusion that cannot be described with conventional methods), new microscopic description methods for the dynamics of nanoparticles and stationary non-equilibrium states of liquids (connection of the transport coefficients with Lyapunov exponents). With Christian Beck he introduced the superstatistics in 2003 .

In 2004 he received the Boltzmann Medal with Eugene Stanley for his (according to the award) fundamental contributions to the statistical mechanics of non-equilibrium, in particular for a theory of transport phenomena in dense gases and the characterization of stationary states in the non-equilibrium case as well as their fluctuations . Cohen is a knight in the Order of the Dutch Lion.

He is the editor of a series of anthologies Fundamental Problems of Statistical Mechanics (6 volumes), which emerged from summer schools in the Netherlands from 1951.

Some reviews by Cohen

  • Editor Statistical mechanics at the turn of the decade , Dekker 1971 (Festschrift for the 70th birthday of Uhlenbeck), therein his essay: The generalization of the Boltzmann equation to higher densities
  • with Walter Thirring (editor) The Boltzmann Equation , Vienna 1973
  • The kinetic theory of dense gases , in Cohen (editor) Fundamental problems of statistical mechanics , Vol. 2, North Holland 1968
  • Kinetic approach to non equilibrium phenomena , in Mehra The physicists concept of nature , Reidel 1973
  • The kinetic theory of fluids- an introduction , Physics Today, January 1984
  • Kinetic theory - understanding nature through collisions , American Journal of Physics, Vol. 60, 1993, p. 524

Web links

Remarks

  1. ^ Obituary , accessed on November 13, 2017
  2. ^ Cohen, Dorfman Difficulties in the kinetic theory of dense gases , J. Math. Phys. Vol. 8, 1967, p. 282
  3. ↑ Literally: For his fundamental contributions to nonequilibrium statistical mechanics, including the development of a theory of transport phenomena in dense gases, and the characterization of measures and fluctuations in nonequilibrium stationary states.
personal data
SURNAME Cohen, EGD
ALTERNATIVE NAMES Cohen, Ezekiel Godert David
BRIEF DESCRIPTION American theoretical physicist
DATE OF BIRTH January 16, 1923
PLACE OF BIRTH Netherlands
DATE OF DEATH September 24, 2017