A new exact quantum mechanical propagator

The authors derive a closed-form expression for the time-dependent propagator for a quantum mechanical particle which is subject to an external force which is the sum of (i) a reflecting half-plane barrier with a straight edge, and (ii) a harmonic force pointing towards a point of the edge. This new addition to the short list of exactly known quantum mechanical Green functions is a simple combination of exponential functions and Fresnel integrals, the arguments of which are combinations of trigonometric function

Acquisition of aspect and aktionsart by children in croatian and french

Our results indicate some differences in the use of aspect between French and Croatian speaking children. In Croatian language children always manage to keep the appropriate aspect, unlike French children. However, the imperfective aspect seems to be better acquired in French children than the perfective aspect. The perfective aspect, the marked form both in French as well as in Croatian, is related to the lexical meaning of the verbs. The acquisition of the Aktionsart in both languages seems to be more a matter of semantics than of morphology. Furthermore, our data suggest the existence of a specific developmental trend in the use of Aktionsart (intensive, iterative and inchoative), which is similar for children speaking Slavic and Romanic languages

Entgegnung auf die Erwiderung von Herbert Hax

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Bayesian Estimates in Time-Series Models

Autoregressive (AR), moving-average (MA), and autoregressive- moving average (ARMA) models are very popular in time-series analysis. Many problems of estimating their parameters and testing hypotheses are only solved asymptotically. The derivation of asymptotic results is usually not easy. An alternative approach to such problems is the Bayesian approach. It is assumed that the parameters of the models are random variables. There are theorems ensuring that under general assumptions the asymptotic posterior distribution does not depend on the prior distribution. As the derivation of the results is usually easier in the Bayesian approach, we can use this procedure particularly for the statistical analysis of more complicated models