Investigation of the Galactic Magnetic Field with Ultra-High Energy Cosmic Rays

We present a method to correct for deflections of ultra-high energy cosmic rays in the galactic magnetic field. We perform these corrections by simulating the expected arrival directions of protons using a parameterization of the field derived from Faraday rotation and synchrotron emission measurements. To evaluate the method we introduce a simulated astrophysical scenario and two observables designed for testing cosmic ray deflections. We show that protons can be identified by taking advantage of the galactic magnetic field pattern. Consequently, cosmic ray deflection in the galactic field can be verified experimentally. The method also enables searches for directional correlations of cosmic rays with source candidates.Comment: 12 pages, 3 figures, presented at the Eur. Phys. Soc. Conf. on High Energy Physics, Jul. 2015, Vienna, Austria, and the 34th Intern. Cosmic Ray Conf., Jul. 2015, The Hague, The Netherland

Superfluid hydrodynamics in the inner crust of neutron stars

The inner crust of neutron stars is supposed to be inhomogeneous and composed of dense structures (clusters) that are immersed in a dilute gas of unbound neutrons. Here we consider spherical clusters forming a BCC crystal and cylindrical rods arranged in a hexagonal lattice. We study the relative motion of these dense structures and the neutron gas using superfluid hydrodynamics. Within this approach, which relies on the assumption that Cooper pairs are small compared to the crystalline structures, we find that the entrainment of neutrons by the clusters is very weak since neutrons of the gas can flow through the clusters. Consequently, we obtain a low effective mass of the clusters and a superfluid density that is even higher than the density of unbound neutrons. Consequences for the constraints from glitch observations are discussed.Comment: 13 pages, 12 figures, figures and discussions added. Accepted in Phys. Rev.

Collective Modes in a Superfluid Neutron Gas within the Quasiparticle Random-Phase Approximation

We study collective excitations in a superfluid neutron gas at zero temperature within the quasiparticle random phase approximation. The particle-hole residual interaction is obtained from a Skyrme functional, while a separable interaction is used in the pairing channel which gives a realistic density dependence of the pairing gap. In accordance with the Goldstone theorem, we find an ungapped collective mode (analogous to the Bogoliubov-Anderson mode). At low momentum, its dispersion relation is approximately linear and its slope coincides with the hydrodynamic speed of sound calculated with the Skyrme equation of state. The response functions are compared with those obtained within the Landau approximation. We also compute the contribution of the collective mode to the specific heat of the neutron gas, which is relevant for the thermodynamic properties of the inner crust of neutron stars.Comment: 12 page

Liquid-gas coexistence vs. energy minimization with respect to the density profile in the inhomogeneous inner crust of neutron stars

We compare two approaches to describe the inner crust of neutron stars: on the one hand, the simple coexistence of a liquid (clusters) and a gas phase, and on the other hand, the energy minimization with respect to the density profile, including Coulomb and surface effects. We find that the phase-coexistence model gives a reasonable description of the densities in the clusters and in the gas, but the precision is not high enough to obtain the correct proton fraction at low baryon densities. We also discuss the surface tension and neutron skin obtained within the energy minimization.Comment: 7 pages, 8 figures, to be published in Phys. Rev.

The Nuclear Window to the Extragalactic Universe

We investigate two recent parameterizations of the galactic magnetic field with respect to their impact on cosmic nuclei traversing the field. We present a comprehensive study of the size of angular deflections, dispersion in the arrival probability distributions, multiplicity in the images of arrival on Earth, variance in field transparency, and influence of the turbulent field components. To remain restricted to ballistic deflections, a cosmic nucleus with energy E and charge Z should have a rigidity above E/Z=6 EV. In view of the differences resulting from the two field parameterizations as a measure of current knowledge in the galactic field, this rigidity threshold may have to be increased. For a point source search with E/Z>60 EV, field uncertainties increase the required signal events for discovery moderately for sources in the northern and southern regions, but substantially for sources near the galactic disk.Comment: 15 pages, 30 figures, few additional sentences and references as in accepted publicatio

Origins of Extragalactic Cosmic Ray Nuclei by Contracting Alignment Patterns induced in the Galactic Magnetic Field

We present a novel approach to search for origins of ultra-high energy cosmic rays. These particles are likely nuclei that initiate extensive air showers in the Earth's atmosphere. In large-area observatories, the particle arrival directions are measured together with their energies and the atmospheric depth at which their showers maximize. The depths provide rough measures of the nuclear charges. In a simultaneous fit to all observed cosmic rays we use the galactic magnetic field as a mass spectrometer and adapt the nuclear charges such that their extragalactic arrival directions are concentrated in as few directions as possible. Using different simulated examples we show that, with the measurements on Earth, reconstruction of extragalactic source directions is possible. In particular, we show in an astrophysical scenario that source directions can be reconstructed even within a substantial isotropic background.Comment: 14 pages, 15 figure

Knowledge Accessibility and Regional Economic Growth

This paper analyzes the role of knowledge accessibility in re¬gional economic growth. The research question is the following: can the variation in knowledge accessibility between regions in a given period explain the variation in their growth performance in subsequent periods? As knowledge measures, we use company R&D, university R&D and patents. A main assumption in the paper is that knowledge accessibilities as a measure of knowledge potentials transform into potential knowledge flows. Our regression results indicate that the intra-municipal and intra-regional knowledge accessibilities of municipalities are significant and capable of ex¬plaining a significant share of the variation in growth of value added per employee between Swedish municipalities. However, the inter-regional knowledge accessibility of municipalities turned out to be insignificant. This is interpreted as a clear indication of spatial dependence in the sense that the knowledge resources in a given municipality tend to have a positive effect on the growth of another municipality, conditional on that the municipalities belongs to the same functional region. Thus, the results of the analysis indicate that knowledge flows transcend municipal borders, but that they tend to be bounded within functional regions. Also, the analysis shows that there is no remaining spatial correlation among the residuals of the spatial units (municipalities) when using accessibility measures in the model, which confirms that the spatial dependence is captured by the accessibility variables.

C Back-End for a Decompiler

Práce popisuje implementaci zadní části zpětného překladače produkujícího kód v jazyce C. Obsahuje základní informace o principech a využití reverzního inženýrství v oblasti informačních technologií i mimo něj. Hlavním cílem je vytvořit zadní část zpětného překladače, která bude generovat kód ekvivalentní vůči vstupu, který bude opět přeložitelný do binární formy se zachováním stejné funkčnosti jako zdrojový binární kód. Výstupem je implementace tříd v jazyce C++, vykonávající popisovanou činnost jako součást obecného dekompilátoru, který je vyvíjený v rámci projektu Lissom.This thesis deals with the implementation of the back-end of the decompiler, which produces a code in C language. It contains basic information about the principals and using of the reverse engineering either in the area of information technology or apart from it. The main goal is to create the back-end of the decompiler which would generate a code that would be equivalent against the input and will be translatable into a binary code. Functionality of the output code will be conserved in state of the functionality of the source code. The output is the implementation of the classes in C++ language. It does described activity as a part of the general decompiler which is developed in terms of the project Lissom.