Space-time Dependence Research Articles

Linear response function for quantum mechanical system

The linear response function for external fields with arbitrary space-time dependence is calculated for various systems in thermal equilibrium. First we derive the general expressions for free fermions and bosons. In particular the superconducting properties of free bosons are investigated. Secondly the influence of a weak repulsion between the bosons on their superconducting properties is investigated. Finally the response function for electrons with the BCS Hamiltonian is calculated exactly in the strong coupling limit.

多領域原子炉の起動時における空間動特性の解析

The space dependent kinetic behavior of the multi-region reactor is calculated by the direct difference method from its subcritical state to supercritical state. This analysis contains the delayed neutron effect, the space-time dependence of the control rod absorption, and the reactivity feedback.Introducing h(t) which is a measure of transient multiplication, the analysis can be made more visible. The result shows the space-time behavior of rods contributes to reactor kinetics remarkably.

Zum Aufbau der Quantenfeldtheorie ohne Lagrangeformalismus

It is investigated to what extent the quantum theory of elementary particles can be built up by using the following principle only: « There exists an irreducible representation of the algebra of creation-and annihilation operatorsa+,a, and the infinitesimal transformations of the inhomogeneous Lorentz group can be constructed out of them. » The representation of the inhomogeneous Lorentz group can then be split up in irreducible ones classified byWigner and describing different sorts of elementary particles. Space-time dependence of all operators is introduced by a unitary transformation of thea+,a. Energy-momentumtensors and charge-current vectors are found without use of fields. Fields and field-equations, corresponding to the various sorts of elementary particles, may also be set up but are dispensable. Interactions are introduced as unitary transformations of thea+,a, mixing the irreducible representations of the Lorentz group. This corresponds to in general non-local interaction terms in the Lagrange formalism.