Titlebook: Recent Progress in Many-Body Theories; Volume 4 E. Schachinger,H. Mitter,H. Sormann Book 1995 Plenum Press, New York 1995 Potential.chemist

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gerontocracy

Cycles of the Transition Processes as Basic Idea of Ludwig Boltzmann,e k is momentum, r is coordinate, t is time, ё.is the particle energy, F is a force. The general form of the collision integral ... is:.Here Wkk’ and Wk’k probabilities of scattering k’ → k and k → k’. In the quantum case the . is slightly modified: the multipliers (1 ± f(k)) and (1 ± . appear befor

熔岩

Systematics and Numerics in Many-Body Systems,h systems. However, only a single approximation, for example, the random phase approximation (RPA) does not necessarily give a correct physical result. It can be estimated, in many cases, using systematic approaches. This strategy is called “systematics”. This systematics requires almost automatical

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Multiphonon Excitations in Bose Films,aphite substrate. Undoubtedly the best . approximation to a complete theory of excitations in bulk .He is the Feynman theory.. At the heart of the Feynman theory is the assumption that the phonon-maxon-roton excitations are density fluctuations that have been excited out of the ground state. More ex

Cloudburst

Theory of 3He Submonolayers in 4He Films,he impetus has been provided by electronic systems because of the intense interest in high temperature superconductivity and the quantum Hall effect. .He physically adsorbed into the surface of .He superfluid films provides an additional example of a strongly interacting many-fermion system in two-d

BRIBE

Impurity Distribution in Helium Droplets,mit. They are therefore an excellent laboratory for the study of finite-size dependence of physical properties of a many-body system such as superfluidity or the excitation spectrum. However, despite many theoretical predictions concerning their ground and excited states (see Ref. . and references t

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bizarre

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Research of Appropriate Treatments of the Various Aspects of the Electron Correlation in Molecules the quantum chemists during the seventies and the eighties. The very last years have seen a major event with the sudden conversion of prominent pionneers in the molecular many-body problem to Density Functional approaches. One may quote J. Pople, who had made popular and developped the Rayleigh-Schr

phytochemicals

A Coupled Cluster Approach to the Electron Correlation Problem Using a Correlated Reference State,osed shell systems.. Several generalizations to encompass multireference functions, leading to CC theories for open-shells, have been suggested in recent years. in the framework of effective hamiltonians, which have offered interesting possiblities of computing directly energy differences of spectro