Ein qualitatives Kriterium für die Konvergenz der assoziierten Kettenbrüche

Ohne Zusammenfassung     

Über die asymptotische Verteilungsfunktion rekurrenter Winkelvariablen

Ohne Zusammenfassung     

Über die automorphen Transformationen beschränkter nicht-singulärer hermitescher Formen

Ohne Zusammenfassung     

Compact eye-safe laser sources based on OPOs with KTP or PPKTP crystals

We report on compact eye-safe nanosecond laser sources emitting in the 1.5 μm wavelength range based on non-critically phase-matched parametric interaction in optical parametric oscillators (OPOs) with KTP and periodically poled KTP (PPKTP) crystals, pumped by the fundamental frequency of Nd:YAG lasers. As much as 250 μJ signal pulse energy at 1.5 μm wavelength, 6.5 ns FWHM pulse-width, has been obtained in a PPKTP-OPO, extracavity pumped by a Nd:YAG microlaser oscillator–amplifier at 650 μJ pump pulse energy, 8 ns pulse-width. A single signal pulse of 2.7-mJ output energy at 1.57 μm wavelength, less than 5 ns pulse-width, was generated in a KTP-OPO, intracavity pumped by a passively Q-switched Nd:YAG laser.     

Specific heat of a fermionic atomic cloud in the unitary regime

In the unitary regime, when the scattering amplitude greatly exceeds in magnitude the average interparticle separation, and below the critical temperature thermal properties of an atomic fermionic cloud are governed by the collective modes, specifically the Bogoliubov-Anderson sound modes. The specific heat of an atomic cloud in an elongated trap, in particular, has a rather complex temperature dependence, which changes from an exponential behavior at very low temperatures (T < h omega(parallel)), to proportional T for h omega(parallel) < T < h omega(perpendicular) and then continuously to proportional T4 at temperatures just below the critical temperature, when the surface modes play a dominant role. Only the low (h omega(parallel) < T < h omega(perpendicular)) and high (h omega(perpendicular) < T < T(c)) temperature power laws are well defined. For the intermediate temperatures one can introduce at most a gradually increasing with temperature exponent.     

On the process of successive approximation in initial value problems

Summary The convergence of the process of the successive approximations for the initial value problem dw/dz=f(z, w), w(0)=0, is studied in the complex field. The resulting z-domains of convergence are more favorable than those supplied by the classical approach. The improvement is made possible by the use of a ? principle of subordination ?, which allows a ? comparison test ? relative to the real field.     

A new method for separating the centre-of-mass motion of clusters in-nuclei

A method for separating the centre-of-mass motion of a two or more particle cluster is developed. This method works for an arbitrary central shell model potential. Only the internal motion wave function must be previously defined. Formulas are obtained for the case of clusters with arbitrary angular momenta of the internal motion and with constituent particles of unequal masses. The problem of separating the relative motion of a pair of particles with previously defined centre-of-mass motion is also solved. As a byproduct, is useful integral formula for generalized Talmi-Moshinsky coefficients is obtained. Some applications of the method are demonstrated in calculating the overlap interests to radioactive states, the form factors for direct x-transfer reactions and the two-parties interaction matrix elements.