7 research outputs found
Theory of strongly correlated f and d-electron systems. I. Exact Hamiltonian, Hubbard-Anderson models and perturbation theory near atomic limit within non-orthogonal basis set
The theory of correlated electron systems is formulated in a form which
allows to use as a reference point an ab initio band structure theory (AIBST).
The theory is constructed in two steps. As a first step the total Hamiltonian
is transformed into a correlated form. In order to elucidate the microscopical
origin of the parameters of the periodical Hubbard-Anderson model (PHAM) the
terms of the full Hamiltonian which have the operator structure of PHAM are
separated. It is found that the matrix element of mixing interaction includes
ion-configuration and number-of-particles dependent contributions from the
Coulomb interaction. In a second step the diagram technique (DT) is developed
by means of generalization of the Baym-Kadanoff method for correlated systems.Comment: 40 pages, 6 figure
Taking International Law Seriously - On the German Approach to International Law
The short article outlines the systemic characteristics of what is identified here as the
German approach to international law. Starting from the post-WW II situation of
German legal scholarship, the paper describes a holistic approach to international law as
a unified legal system which is characterized by both a true commitment to the rule of
law and a constructive vision of the International Community based on constitutional
form