Generalizations of Iwasawa's 'Riemann-Hurwitz' Formula for Cyclic p-Extensions of Number Fields

We produce generalizations of Iwasawa's `Riemann-Hurwitz' formula for number fields. These generalizations apply to cyclic extensions of number fields of degree p^n for any positive integer n. We first deduce some congruences and inequalities and then use these formulas to establish a vanishing criterion for Iwasawa \lambda-invariants which generalizes a result of Takashi Fukuda et. al. for totally real number fields.Comment: 13 page

Imprints of the QCD Phase Transition on the Spectrum of Gravitational Waves

We have investigated effects of the QCD phase transition on the relic GW spectrum applying several equations of state for the strongly interacting matter: Besides the bag model, which describes a first order transition, we use recent data from lattice calculations featuring a crossover. Finally, we include a short period of inflation during the transition which allows for a first order phase transition at finite baryon density. Our results show that the QCD transition imprints a step into the spectrum of GWs. Within the first two scenarios, entropy conservation leads to a step-size determined by the relativistic degrees of freedom before and after the transition. The inflation of the third scenario much stronger attenuates the high-frequency modes: An inflationary model being consistent with observation entails suppression of the spectral energy density by a factor of ~10^(-12).Comment: 11 pages, 13 figure

Laghi di Monticchio (Southern Italy, Region Basilicata): genesis of sediments—a geochemical study

International audienceThe sedimentation record of Lago Grande di Monticchio (LGM) is one of the most prominent paleoclimatic archives in the on-glaciated areas of Europe. However, the modern lake system has never been the subject of intense limnological studies. On the basis of hydrochemical water profiles, detailed investigations of sediment short cores and in situ pore water profiles from the littoral to the profundal zone, we elucidate spatial variations of sediment genesis within the lake basin and the importance of various depth sections for the lake's internal nutrient cycling. Sediments from the smaller meromictic Lago Piccolo di Montichio are discussed as a reference. Our study demonstrates: (i) distinctly higher sediment accumulation for the centre of the lake basin by focussing of the settling particle flux; (ii) decline of carbonate from the littoral to the profundal zones; (iii) nonsynchronous change of calcite net-accumulation for various water depths; (iv) exceptionally high cation release from sediments covering the steeply inclining sector of the lake basin; (v) relatively constant dissolved silica concentrations in the pore waters (SiO2 *42 mg/l) independent of water depth and sediment composition; (vi) influx of oxygen-bearing groundwater into the anoxic hypolimnion after heavy rainfall and the associated precipitation of Fe-oxihydroxides; (vii) higher release of NH4 by anaerobic degradation of organic matter at a water depth of 23 m than for sediments at a maximum water depth of 32 m, whereby the latter reflects the importance of seasonal sediment re-oxidation for anaerobic degradation of organic debris; (viii) although seasonal reoxidation of sediments from various water depths is quite different, Oxygen Index values of LGM sediments fall in a small range, which reflects rapid microbial consumption of seasonally re-generated easily bio-degradable organic molecules

Millimeter-wave communication for a last-mile autonomous transport vehicle

Low-speed autonomous transport of passengers and goods is expected to have a strong, positive impact on the reliability and ease of travelling. Various advanced functions of the involved vehicles rely on the wireless exchange of information with other vehicles and the roadside infrastructure, thereby benefitting from the low latency and high throughput characteristics that 5G technology has to offer. This work presents an investigation of 5G millimeter-wave communication links for a low-speed autonomous vehicle, focusing on the effects of the antenna positions on both the received signal quality and the link performance. It is observed that the excess loss for communication with roadside infrastructure in front of the vehicle is nearly half-power beam width independent, and the increase of the root mean square delay spread plays a minor role in the resulting signal quality, as the absolute times are considerably shorter than the typical duration of 5G New Radio symbols. Near certain threshold levels, a reduction of the received power affects the link performance through an increased error vector magnitude of the received signal, and subsequent decrease of the achieved data throughput

Detecting quark matter in the early universe by gravitational waves

For large baryochemical potential, strongly interacting matter might undergo a first order phase transition at temperatures T ~ 100-200 MeV. Within standard cosmology, however, the chemical potential is assumed to be very small leading to a crossover. We discuss implications of a first order QCD transition at high chemical potential being consistent with current observations. In this contribution we concentrate on effects on the gravitational wave spectrum. There are other interesting cosmological signals as a modification of the power spectrum of dark matter, the production of stellar black holes, and the seeds for the extragalactic magnetic fields which we briefly address also.Comment: 10 pages, talk given at the symposium "Advances in Nuclear Physics in Our Time", Goa, India, Nov. 28 - Dec. 2, 201

The Case of Food Security

International organizations (IOs) are confronted with a twin challenge in areas of limited statehood (ALS). On the one hand, IOs are governmental organizations qua mandate. Their usual approach – providing a range of services to their members and working with or for a given state – may, however, either be blocked or prove unsustainable in ALS. On the other, ALS present numerous challenges to IO governance, ranging from insecurity to a lack of meta-governance. Yet, we know surprisingly little about how IOs operate in these contexts, and, in particular, which modes of governance they choose for which purposes. How can IOs attain the twin objectives of acting in accordance with their mandate, which gives primacy to governments, and responding to ALS-specific challenges in order to effectively provide food security? This paper addresses IOs’ choice of distinct modes of governance, ranging from bargaining to persuasion. It investigates how different types of IOs use and combine these modes in light of varying ALS-challenges. The empirical observations presented in this paper stem from interviews with IOs (ECHO, FAO, IDB, WFP, and the World Bank) at the level of headquarters and country offices (in Colombia, Côte d’Ivoire, Haiti, Niger, and Sierra Leone), as well as from organizational documents