God and Possible worlds

This article investigates the problems which arise when the concept of possible worlds is applied to modal and existential judgments about God. In presentday logic, philosophy and linguistics, modal statements are conventionally understood as coordinating the situation described or relationships between situations with possible worlds. Existential statements are in this case seen as coordinating what is being stated by default with reality. But a judgment about God does not always imply a link between His existence or His possession of certain properties and some concrete world or even the whole array of possible worlds. Having studied the problem, the author of the paper has come to the conclusion that semantics of possible worlds is compatible with preferable (from the point of view of theism) readings of diffi cult cases of the type in question if one of the two requirements is met, namely if these statements are not assigned the sense of the truth or they are understood as hidden metaphors

Towards Bright Single-Photon Emission in Elliptical Micropillars

In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. The widely used resonant excitation with cross-polarization filtering usually leads to at least a two-fold reduction in the single-photon counts rate, since single-photon emission is usually unpolarized, or its polarization state is close to that of the exciting laser. One of the solutions is the use of polarization-selective microcavities, which allows one to redirect most of the QD emission to a specific polarization determined by the optical mode of the microcavity. In the present work, elliptical micropillars with distributed Bragg reflectors are investigated theoretically and experimentally as a promising design of such polarization-selective microcavities. The impact of ellipticity, ellipse area and verticality of the side walls on the splitting of the optical fundamental mode is investigated. The study of the near-field pattern allows us to detect the presence of higher-order optical modes, which are classified theoretically. The possibility of obtaining strongly polarized single-photon QD radiation associated with the short-wavelength fundamental cavity mode is shown

Hyperon signatures in the PANDA experiment at FAIR

We present a detailed simulation study of the signatures from the sequential decays of the triple-strange pbar p -> Ω+Ω- -> K+ΛbarK- Λ -> K+pbarπ+K-pπ- process in the PANDA central tracking system with focus on hit patterns and precise time measurement. We present a systematic approach for studying physics channels at the detector level and develop input criteria for tracking algorithms and trigger lines. Finally, we study the beam momentum dependence on the reconstruction efficiency for the PANDA detector