Application of Ewald's Method for Efficient Summation of Dyon Long-Range Potentials

We study a model of dyons for SU(2) Yang-Mills theory at finite temperature T < T_c, in particular its ability to generate a confining force between a static quark antiquark pair. The interaction between dyons corresponds to a long-range 1/r potential, which in naive treatments with a finite number of dyons typically gives rise to severe finite volume effects. To avoid such effects we apply the so-called Ewald method, which has its origin in solid state physics. The basic idea of Ewald's method is to consider a finite number of dyons inside a finite cubic volume and enforce periodicity of this volume. We explain the technicalities of Ewald's method and outline how the method can be applied to a wider class of 1/r^p long-range potentials.Comment: 8 pages, 4 figures, contribution to conference "Confinement X

The Crisis of Liberal Interventionism and the Return of War

Liberal interventionism is in crisis, being weakened both from within and without. From Kabul to Kyiv and beyond, the contributions to our thematic issue reveal that the crisis of liberal interventionism has unraveled differently than previously understood. In countries of the Global North, it stretched out in different ways, depending on the political culture, party/coalition in power, or institutional path dependencies. In countries of the Global South, mandate-specific benchmarks in addition to the neglect of local agencies by both interveners and domestic elites, produced unintended consequences and a backlash effect. The articles in this thematic issue contribute to a better understanding of the crisis of liberal interventionism by unpacking the global fragmentation of collective security instruments, patterns and conditions of foreign policy change in liberal democracies, intervention failure in Afghanistan, alternative forms of interventionism like the one of the Wagner Group, international orientation change through the Zeitenwende, or counter-terrorism and deterrence postures. To conclude, the thematic issue critically investigates whether singing the swansong of liberal interventionism is premature

Individual Risk Attitudes: Measurement, Determinants and Behavioral Consequences

This paper studies risk attitudes using a large representative survey and a complementaryexperiment conducted with a representative subject pool in subjects’ homes. Using aquestion asking people about their willingness to take risks “in general”, we find thatgender, age, height, and parental background have an economically significant impacton willingness to take risks. The experiment confirms the behavioral validity of thismeasure, using paid lottery choices. Turning to other question about risk attitudesin specific contexts, we find similar results on the determinants of risk attitudes, andalso shed light on the deeper question of stability of risk attitudes across contexts. Weconduct a horse race of the ability of different measures to explain risky behaviorssuch as holdings stocks, occupational choice, and smoking. The question about risktakingin general generates the best all-around predictor of risky behavior. (JEL codes:D0, D1, D80, D81, C91, C93, J16, J24, I1).education, training and the labour market;

Individual Risk Attitudes: New Evidence from a Large, Representative, Experimentally-Validated Survey

This paper presents new evidence on the distribution of risk attitudes in the population, using a novel set of survey questions and a representative sample of roughly 22,000 individuals living in Germany. Using a question that asks about willingness to take risks in general, on an 11-point scale, we find evidence of heterogeneity across individuals, and show that willingness to take risks is negatively related to age and being female, and positively related to height and parental education. We test the behavioral relevance of this survey measure by conducting a complementary field experiment, based on a representative sample of 450 subjects, and find that the general risk question is a good predictor of actual risk-taking behavior. We then use a more standard lottery question to measure risk preferences in our sample of 22,000, and find similar results regarding heterogeneity and determinants of risk preferences, compared to the general risk question. The lottery question also makes it possible to estimate the coefficient of relative risk aversion for each individual in the sample. Using five questions about willingness to take risks in specific domains - car driving, financial matters, sports and leisure, career, and health - the paper also studies the impact of context on risk attitudes, finding a strong but imperfect correlation across contexts. Using data on a collection of risky behaviors from different contexts, including traffic offenses, portfolio choice, smoking, occupational choice, participation in sports, and migration, the paper compares the predictive power of all of the risk measures. Strikingly, the general risk question predicts all behaviors whereas the standard lottery measure does not. The best predictor for any specific behavior is typically the corresponding context-specific measure.Risk Preferences, Experimental Validation, Field Experiment, SOEP, Gender Differences, Context, Age, Height, Subjective Well-Being, Migration, Occupational Choice, Health

Individual Risk Attitudes: New Evidence from a Large, Representative, Experimentally-Validated Survey

This paper presents new evidence on the distribution of risk attitudes in the population, using a novel set of survey questions and a representative sample of roughly 22,000 individuals living in Germany. Using a question that asks about willingness to take risks on an 11-point scale, we find evidence of heterogeneity across individuals, and show that willingness to take risks is negatively related to age and being female, and positively related to height and parental education. We test the behavioral relevance of this survey measure by conducting a complementary field experiment, based on a representative sample of 450 subjects, and find that the measure is a good predictor of actual risk-taking behavior. We then use a more standard lottery question to measure risk preference, and find similar results regarding heterogeneity and determinants of risk preferences. The lottery question makes it possible to estimate the coefficient of relative risk aversion for each individual in the sample. Using five questions about willingness to take risks in specific domains - car driving, financial matters, sports and leisure, career, and health - the paper also studies the impact of context on risk attitudes, finding a strong but imperfect correlation across contexts. Using data on a collection of risky behaviors from different contexts, including traffic offenses, portfolio choice, smoking, occupational choice, participation in sports, and migration, the paper compares the predictive power of all of the risk measures. Strikingly, the general risk question predicts all behaviors whereas the standard lottery measure does not. The best overall predictor for any specific behavior is typically the corresponding context-specific measure. These findings call into the question the current preoccupation with lottery measures of risk preference, and point to variation in risk perceptions as an understudied determinant of risky behavior.Risk preferences; Preference stability; Experimental validation; Field experiment; SOEP; Gender differences; Age; Height; Subjective well-being

Individual Risk Attitudes: Measurement, Determinants and Behavioral Consequences

This paper studies risk attitudes using a large representative survey and a complementary experiment conducted with a representative subject pool in subjects'' homes. Using a question asking people about their willingness to take risks "in general", we find that gender, age, height, and parental background have an economically significant impact on willingness to take risks. The experiment confirms the behavioral validity of this measure, using paid lottery choices. Turning to other questions about risk attitudes in specific contexts, we find similar results on the determinants of risk attitudes, and also shed light on the deeper question of stability of risk attitudes across contexts. We conduct a horse race of the ability of different measures to explain risky behaviors such as holdings stocks, occupational choice, and smoking. The question about risk-taking in general generates the best all-around predictor of risky behavior.Economics ;

Comparison of different lattice definitions of the topological charge

We present a comparison of different definitions of the topological charge on the lattice, using a small-volume ensemble with 2 flavours of dynamical twisted mass fermions. The investigated definitions are: index of the overlap Dirac operator, spectral projectors, spectral flow of the Hermitian Wilson-Dirac operator and field theoretic with different kinds of smoothing of gauge fields (HYP and APE smearings, gradient flow, cooling). We also show some results on the topological susceptibility.Comment: 7 pages, 2 figures, presented at the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, Columbia University, New York, NY, US

The D-ring, Not the A-ring, Rotates in Synechococcus OS-B' Phytochrome

Phytochrome photoreceptors in plants and microorganisms switch photochromically between two states, controlling numerous important biological processes. Although this phototransformation is generally considered to involve rotation of ring D of the tetrapyrrole chromophore, Ulijasz et al. (Ulijasz, A. T., Cornilescu, G., Cornilescu, C. C., Zhang, J., Rivera, M., Markley, J. L., and Vierstra, R. D. (2010) Nature 463, 250–254) proposed that the A-ring rotates instead. Here, we apply magic angle spinning NMR to the two parent states following studies of the 23-kDa GAF (cGMP phosphodiesterase/adenylyl cyclase/FhlA) domain fragment of phytochrome from Synechococcus OS-B′. Major changes occur at the A-ring covalent linkage to the protein as well as at the protein residue contact of ring D. Conserved contacts associated with the A-ring nitrogen rule out an A-ring photoflip, whereas loss of contact of the D-ring nitrogen to the protein implies movement of ring D. Although none of the methine bridges showed a chemical shift change comparable with those characteristic of the D-ring photoflip in canonical phytochromes, denaturation experiments showed conclusively that the same occurs in Synechococcus OS-B′ phytochrome upon photoconversion. The results are consistent with the D-ring being strongly tilted in both states and the C15=C16 double bond undergoing a Z/E isomerization upon light absorption. More subtle changes are associated with the A-ring linkage to the protein. Our findings thus disprove A-ring rotation and are discussed in relation to the position of the D-ring, photoisomerization, and photochromicity in the phytochrome family

Party politics at the water's edge:Contestation of military operations in Europe

This paper contributes to current debates on the politicization of international politics by examining party-political contestation of peace and security missions. It is guided by two inter-related questions, (a) to what extent deployment decisions are contested amongst political parties and (b) what drives such contestation. We examine data from a new data set on parliamentary votes on deployment decisions in France, Germany, Spain, and the United Kingdom and from the Chapel Hill Expert Survey. Against conventional wisdom and in an effort to address the often-overlooked role of political parties, we find that military deployments have been systematically contested amongst political parties across Europe. Further, we find that contestation is driven by the left/right axis, as opposed to newer cleavages captured here by the so-called gal/tan axis. We also find evidence that patterns of contestation depend on parties' positions in government or opposition, a factor we relate to bureaucratic and international pressures on the parties in office, and to political opportunities for opposition parties

The Party Politics of Legislative:Executive Relations in Security and Defence Policy

The move from territorial defence to ‘wars of choice’ has influenced the domestic politics of military interventions. This paper examines the extent to which both the substance and the procedure of military interventions are contested among political parties. Regarding the substance, our analysis of Chapel Hill Expert Survey data demonstrates that across European states political parties on the right are more supportive of military missions than those on the left. On the decision-making procedures, our case studies of Germany, France, Spain and the United Kingdom show that political parties on the left tend to favour strong parliamentary control whereas those on the right tend to prefer an unconstrained executive, although with differences across countries. These findings challenge the view that ‘politics stops at the water’s edge’ and contribute to a better understanding of how political parties and parliaments influence military interventions