Product Integral Representations of Wilson Lines and Wilson Loops, and Non-Abelian Stokes Theorem

We make use of product integrals to provide an unambiguous mathematical representation of Wilson line and Wilson loop operators. Then, drawing upon various properties of product integrals, we discuss such properties of these operators as approximating them with partial sums, their convergence, and their behavior under gauge transformations. We also obtain a surface product integral representation for the Wilson loop operator. The result can be interpreted as the non-abelian version of Stokes theorem.Comment: 20 pages, LaTe

Design and Sensitivity of the Radio Neutrino Observatory in Greenland (RNO-G)

This article presents the design of the Radio Neutrino Observatory Greenland (RNO-G) and discusses its scientific prospects. Using an array of radio sensors, RNO-G seeks to measure neutrinos above 10 PeV by exploiting the Askaryan effect in neutrino-induced cascades in ice. We discuss the experimental considerations that drive the design of RNO-G, present first measurements of the hardware that is to be deployed and discuss the projected sensitivity of the instrument. RNO-G will be the first production-scale radio detector for in-ice neutrino signals.Comment: 51 pages, 27 figures, prepared for JINS

Design and Sensitivity of the Radio Neutrino Observatory in Greenland (RNO-G)

This article presents the design of the Radio Neutrino Observatory Greenland (RNO-G) and discusses its scientific prospects. Using an array of radio sensors, RNO-G seeks to measure neutrinos above 10 PeV by exploiting the Askaryan effect in neutrino-induced cascades in ice. We discuss the experimental considerations that drive the design of RNO-G, present first measurements of the hardware that is to be deployed and discuss the projected sensitivity of the instrument. RNO-G will be the first production-scale radio detector for in-ice neutrino signals

The interplay of ice-firn model and station calibration in RNO-G

In-ice radio neutrino detectors, such as the newly constructed and operational Radio Neutrino Observatory in Greenland (RNO-G), rely on ice models to understand the in-ice signal propagation. Most often the ice is approximated in first order by a single exponential profile because it allows for computationally fast signal propagation. However, such models do not encompass the whole complexity of the ice, which may lead to systematic uncertainties. This is especially true for the upper part of the ice (the firn) where most of the RNO-G antennas are situated. Therefore, we developed a new refractive index model of the ice at Summit Station which can be used in both simulation and analysis. This contribution shows how both density data and signals from various known radio sources, such as the on board radio pulser and weather balloons, can lead to a more accurate description of the ice. This revised ice model results in a better understanding of signal arrival times, thus resulting in an improved station calibration in RNO-G. In the future we expect to bridge the gap even further by performing dedicated and more rigorous ice measurement in the field

A blind spot in food and nutrition security: where culture and social change shape the local food plate

It is estimated that over 800 million people are hungry each day and two billion are suffering from the consequences of vitamin and mineral deficiencies. While a paradigm shift towards a multi-dimensional and multi-sectoral approach to food and nutrition insecurity is emerging, technical approaches largely prevail to tackle the causes of hunger and malnutrition. Founded in original in-depth field research among smallholder farmers in southwest Kenya, we argue that incorporating cultural or social dimensions in this technical debate is imperative and that by systematically overlooking these dimensions, food insecurity cannot be accurately captured nor properly addressed. Based on a sub-location in rural southwest Kenya where the food plate is rapidly narrowing towards a high-calorie low nutrient diet and where over 80 % of households experience food shortages at least once a year, conclusions suggest that preferences, the local function of food, and the practices that emerge therefrom can affect the regularity of meals and their composition. The findings allow us to complement emerging research and program development with a more comprehensive and locally adapted approach to tackle food and nutrition insecurity