Opposites Do Not Attract: The Impact of Domestic Institutions, Power, and Prior Commitments on Alignment Choices

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146950/1/0020-8833.00055.pd

Retrospective Evaluation of the Five-Year and Ten-Year CSEP-Italy Earthquake Forecasts

On 1 August 2009, the global Collaboratory for the Study of Earthquake Predictability (CSEP) launched a prospective and comparative earthquake predictability experiment in Italy. The goal of the CSEP-Italy experiment is to test earthquake occurrence hypotheses that have been formalized as probabilistic earthquake forecasts over temporal scales that range from days to years. In the first round of forecast submissions, members of the CSEP-Italy Working Group presented eighteen five-year and ten-year earthquake forecasts to the European CSEP Testing Center at ETH Zurich. We considered the twelve time-independent earthquake forecasts among this set and evaluated them with respect to past seismicity data from two Italian earthquake catalogs. In this article, we present the results of tests that measure the consistency of the forecasts with the past observations. Besides being an evaluation of the submitted time-independent forecasts, this exercise provided insight into a number of important issues in predictability experiments with regard to the specification of the forecasts, the performance of the tests, and the trade-off between the robustness of results and experiment duration. We conclude with suggestions for the future design of earthquake predictability experiments.Comment: 43 pages, 8 figures, 4 table

CP-Violating and Charged Current Neutrino Non-standard Interactions in CEν\nuNS

Neutrino non-standard interactions (NSI) can be constrained using coherent elastic neutrino-nucleus scattering. We discuss here two aspects in this respect, namely the effects of (i) charged current NSI in neutrino production and (ii) CP-violating phases associated with neutral current NSI in neutrino detection. Effects of CP-phases require the simultaneous presence of two different flavor-changing neutral current NSI parameters. Applying these two scenarios to the COHERENT measurement, we derive limits on charged current NSI and find that more data is required to compete with the existing limits. Regarding CP-phases, we show how the limits on the NSI parameters depend dramatically on the values of the phases. Accidentally, the same parameters influencing coherent scattering also show up in neutrino oscillation experiments. We find that COHERENT provides complementary constraints on the set of NSI parameters that can explain the discrepancy in the best-fit value of the standard CP-phase obtained by T2K and NO$\nu$A, while the significance with which the LMA-Dark solution is ruled out can be weakened by the presence of additional NSI parameters introduced here.Comment: 15 pages, 5 figure, 1 table; Figure 3 was corrected for other experiments in V

Inverse Design of Three-Dimensional Nanoantennas for Metasurface Applications

Recent advances in manufacturing techniques have been made to match the demand for high performance optical devices. To this end, tremendous research activity has been focused on optical metasurfaces as they offer a unique potential to achieve disruptive designs when paired with innovative fabrication techniques and inverse design tools. However, most metasurface designs have revolved around canonical geometries. While these elements are relatively easy to fabricate, they represent only a small portion of the design space, and rarely offer peak performance in transmission, phase range or field of view. In this work, a Lazy Ant Colony Optimization (LACO) technique is applied in conjunction with a full-wave solver using the Periodic Finite Element Boundary Integral (PFEBI) method to reveal high performing three-dimensional nanoantenna designs with potential applications for a variety of optical devices

Theoretical analysis of thin-wire elliptic antennas

In this communication we extend the state-of-the art by providing closed-form equations for thin-wire elliptical antennas with arbitrary current distributions, valid from low frequencies to the infrared regime. To this end, we derive an electric-field integral equation (EFIE) for imperfectly conducting wires and elliptical geometries. Using this formulation, we obtain unknown arbitrary current distributions through a modal expansion, enabling thus the calculation of far-fields and other radiation parameters. Results shown not only achieve remarkable but also to show the superior design possibilities of elliptical geometries in comparison to the classical circular loops, which may be considered just a particular case of the methodology here presented. Special attention is paid to mathematical details of electric farfield equations, thus providing guidelines to produce efficient codes

A Computationally Efficient Method for Simulating Metal-Nanowire Dipole Antennas at Infrared and Longer Visible Wavelengths

This paper presents a numerically efficient approach for simulating nanowires at infrared and long optical wavelengths. A computationally efficient circuit-equivalent modeling approach based on the electric-field integral-equation (EFIE) formulation is employed to simulate the highly dispersive behavior of nanowires at short wavelengths. The proposed approach can be used both for frequency-domain and for time-domain EFIE formulations. In comparison with widely used full-wave solutions achieved through the finite-difference time-domain method, the circuit-based EFIE formulation results in a sharp reduction of the computational resources while retaining high accuracy.This work was supported in part by the Spanish Ministry of Education under Project PR2009-0443, in part by the Penn State MRSEC under NSF Grant 0213623, in part by the EU FP7/2007-2013 under Grant GA 205294 (HIRF SE project), in part by the Spanish National Projects TEC2010-20841- C04-04, CSD200800068, and DEX-5300002008105, and in part by the Junta de Andalucia Project P09-TIC5327