Green's Functions for Neutrino Mixing

The Green's function formalism for neutrino mixing is presented and the exact oscillation formula is obtained. The usual Pontecorvo formula is recovered in the relativistic limit.Comment: 4 pages, LaTeX (need sprocl.sty). To appear in the Proceedings of the 6th International Symposium on Particles, Strings and Cosmology (PASCOS 98), Boston, 22-27 March 199

The exact formula for neutrino oscillations

We present the exact formula for neutrino oscillations. By resorting to recent results of Quantum Field Theory of fermion mixing, we work out the Green's function formalism for mixed neutrinos. The usual quantum mechanical Pontecorvo formula is recovered in the relativistic limit.Comment: 7 pages, RevTeX, revised version: title changed and some minor change

Statistical Modeling of Epistasis and Linkage Decay using Logic Regression

Logic regression has been recognized as a tool that can identify and model non-additive genetic interactions using Boolean logic groups. Logic regression, TASSEL-GLM and SAS-GLM were compared for analytical precision using a previously characterized model system to identify the best genetic model explaining epistatic interaction of vernalization-sensitivity in barley. A genetic model containing two molecular markers identified in vernalization response in barley was selected using logic regression while both TASSEL-GLM and SAS-GLM included spurious associations in their models. The results also suggest the logic regression can be used to identify dominant/recessive relationships between epistatic alleles through its use of conjugate
operators

Berry phase for oscillating neutrinos

We show the presence of a topological (Berry) phase in the time evolution of a mixed state. For the case of mixed neutrinos, the Berry phase is a function of the mixing angle only.Comment: 7 pages, Revte

Silicate-analogous borosulfates featuring promising luminescence and frequency-doubling (SHG) properties based on a rich crystal chemistry

Our contribution adresses important features of the emerging compound class of silicate-analogous borosulfates, i.e. their rich crystal chemistry, their exciting optical properties and of course their syntheses – the chemistry behind. Silicate-analogous materials comprise tetrahedral anionic basic building units lacking an inversion centre enhancing the chance of non-centrosymmetric surroundings of metal ions promoting excellent optical properties. Since the very first characterization of crystalline borosulfates in 2012 over sixty members have been found. Therein, the reaction of boric and sulfuric acid yields supertetrahedral BX4 (X=SO4) moieties giving rise to a rich crystal chemistry from non-condensed [B(SO4)4]5– anions via band (see Fig.) and layer structures to anionic frameworks [B(SO4)2]– – which can be understood by principles well known from silicates (see Fig.). The selective synthesis of borosulfates can be challenging but we meanwhile found some basic principles helping to selectively synthesize new compounds as phase-pure samples. Great impact is ascribed to the nature of the boron source, the metal (salt) employed and the amount of oleum added. On one hand, borosulfates feature a low coordination strength which is beneficial for the luminescence and UV-Vis properties of compounds containing lanthanide and transition metal ions, such as Ce3+ (see Fig.), Eu3+, Tb3+ or Co2+ and Ni2+. On the other hand, borosulfates frequently adopt non-centrosysmmetric structures yielding optical properties like SHG (second harmonic generation) which – in combination with large band-gaps – makes them highly promising materials for frequency doubling in the high energy regime. Also ionic conductivity was observed recently

Fitting of dust spectra with genetic algorithms - I. Perspectives & Limitations

Aims: We present an automatised fitting procedure for the IR range of AGB star spectra. Furthermore we explore the possibilities and boundaries of this method. Methods: We combine the radiative transfer code DUSTY with the genetic algorithm PIKAIA in order to improve an existing spectral fit significantly. Results: In order to test the routine we carried out a performance test by feeding an artificially generated input spectrum into the program. Indeed the routine performed as expected, so, as a more realistic test set-up, we tried to create model fits for ISO spectra of selected AGB stars. Here we were not only able to improve existing fits, but also to show that a slightly altered dust composition may give a better fit for some objects. Conclusion: The use of a genetic algorithm in order to automatise the process of fitting stellar spectra seems to be very promising. We were able to improve existing fits and further offer a quantitative method to compare different models with each other. Nevertheless this method still needs to be studied and tested in more detail.Comment: 9 pages, 5 figures, accepted for publication in Astronomy and Astrophysic

Feasibility Analysis of Pret a Voter for German Federal Elections

Abstract. Prêt a ̀ Voter is one of the most well-known and most extensively analysed electronic voting systems for polling stations. However, an analysis from a legal point of view has not yet been conducted. The purpose of this paper is to analyse the readiness of Prêt a ̀ Voter for legally binding federal elections in Germany. This case is of particular interest as Germany has with the Constitutional Court Decision from 2009 probably the most restrictive requirements on electronic voting in particular regarding the public nature of elections and verifiability respectively. While many aspects are analysed, some remain open for further legal and technical discussions. Thus, a final decision is not yet possible. Aspects analysed are the ballot paper layout, different processes from ballot printing through to the publishing of results, as well as verifiability, and the overall election management.