Metamaterials for light rays: ray optics without wave-optical analog in the ray-optics limit

Volumes of sub-wavelength electromagnetic elements can act like homogeneous materials: metamaterials. In analogy, sheets of optical elements such as prisms can act ray-optically like homogeneous sheet materials. In this sense, such sheets can be considered to be metamaterials for light rays (METATOYs). METATOYs realize new and unusual transformations of the directions of transmitted light rays. We study here, in the ray-optics and scalar-wave limits, the wave-optical analog of such transformations, and we show that such an analog does not always exist. Perhaps, this is the reason why many of the ray-optical possibilities offered by METATOYs have never before been considered.Comment: 10 pages, 3 figures, references update

Gender differences in research performance and in academic careers

We take up the issue of performance differences between male and female researchers, and investigate the change of performance differences during the early career. In a previous paper it was shown that among starting researchers gendered performance differences seem small to non-existent (Van Arensbergen et al. 2012). If the differences do not occur in the early career anymore, they may emerge in a later period, or may remain absent. In this paper we use the same sample of male and female researchers, but now compare performance levels about 10 years later. We use various performance indicators: full/fractional counted productivity, citation impact, and relative citation impact in terms of the share of papers in the top 10 % highly cited papers. After the 10 years period, productivity of male researchers has grown faster than of female researcher, but the field normalized (relative) citation impact indicators of male and female researchers remain about equal. Furthermore, performance data do explain to a certain extent why male careers in our sample develop much faster than female researchers’ careers; but controlling for performance differences, we find that gender is an important determinant too. Consequently, the process of hiring academic staff still remains biased

The dust SED of dwarf galaxies

Context. High-resolution data from Spitzer, Herschel, and Planck allow us to probe the entire spectral energy distribution (SED) of morphologically separated components of the dust emission from nearby galaxies and allow a more detailed comparison between data and models. Aims. We wish to establish the physical origin of dust heating and emission based on radiation transfer models, that self-consistently connect the emission components from diffuse dust and the dust in massive star forming regions. Methods. NGC 4214 is a nearby dwarf galaxy with a large set of ancillary data, ranging from the ultraviolet (UV) to radio, including maps from Spitzer and Herschel and detections from Planck. We mapped this galaxy with MAMBO at 1.2mm at the IRAM 30m telescope. We extracted separate dust emission components for the HII regions (plus their associated PDRs on pc scales) and for the diffuse dust (on kpc scales). We analysed the full UV to FIR/submm SED of the galaxy using a radiation transfer model that self-consistently treats the dust emission from diffuse and star forming (SF) complexes components, considering the illumination of diffuse dust both by the distributed stellar populations and by escaping light from the HII regions. While maintaining consistency within the framework of this model, we additionally used a model that provides a detailed description of the dust emission from the HII regions and their surrounding PDRs on pc scales. Thanks to the large amount of available data and many previous studies for NGC 4214, very few free parameters remained in the model fitting process. Results. We achieve a satisfactory fit for the emission from HII + PDR regions on pc scales, with the exception of the emission at 8 μm, which is underpredicted by the model. For the diffuse emission we achieve a good fit if we assume that about 40-65% of the emission escaping the HII + PDR regions is able to leave the galaxy without passing through a diffuse ISM, which is not an unlikely scenario for a dwarf galaxy that has recently undergone a nuclear starburst. We determine a dust-to-gas mass ratio of 350-470, which is close to the expected value based on the metallicity. © 2012 ESO

The IceCube Neutrino Observatory: Instrumentation and Online Systems

The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review and proofin

Nonlinear inverse perturbation method in dynamic analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76092/1/AIAA-8245-515.pd

A comparative analysis of the publication behaviour of MSCA fellows

MSCA applicants from South and Eastern European countries underperform researchers from North Western Europe before receiving the grant. However, the median difference disappears by the time of the grant and in the period after this. Due to a higher number of outliers (top performers) among the researchers from North Western Europe, the mean impact scores do remain significantly higher

IceCube-Gen2: A Vision for the Future of Neutrino Astronomy in Antarctica

The recent observation by the IceCube neutrino observatory of an astrophysical flux of neutrinos represents the "first light" in the nascent field of neutrino astronomy. The observed diffuse neutrino flux seems to suggest a much larger level of hadronic activity in the non-thermal universe than previously thought and suggests a rich discovery potential for a larger neutrino observatory. This document presents a vision for an substantial expansion of the current IceCube detector, IceCube-Gen2, including the aim of instrumenting a $10\,\mathrm{km}^3$ volume of clear glacial ice at the South Pole to deliver substantial increases in the astrophysical neutrino sample for all flavors. A detector of this size would have a rich physics program with the goal to resolve the sources of these astrophysical neutrinos, discover GZK neutrinos, and be a leading observatory in future multi-messenger astronomy programs.Comment: 20 pages, 12 figures. Address correspondence to: E. Blaufuss, F. Halzen, C. Kopper (Changed to add one missing author, no other changes from initial version.

Electron-muon ranger: performance in the MICE muon beam

The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100–280 MeV/c