N=1\mathcal{N}=1 Liouville SCFT in Four Dimensions

We construct a four supercharges Liouville superconformal field theory in four dimensions. The Liouville superfield is chiral and its lowest component is a log-correlated complex scalar whose real part carries a background charge. The action consists of a supersymmetric Paneitz operator, a background supersymmetric $\mathcal{Q}$-curvature charge and an exponential potential. It localizes semiclassically on solutions that describe curved superspaces with a constant complex supersymmetric $\mathcal{Q}$-curvature. The theory is non-unitary with a continuous spectrum of scaling dimensions. We study the dynamics on the supersymmetric 4-sphere, show that the classical background charge is not corrected quantum mechanically and calculate the super-Weyl anomaly. We derive an integral form for the correlation functions of vertex operators.Comment: 24 pages; revise

Generalized Portfolio Performance Measures: Optimal Overweighting of Fees Relative to Sample Returns

Performance measures such as alpha and the Sharpe ratio are typically based on sample returns net of fees. This implies the same weighting to sample returns and to fees. However, sample return parameters are noisy estimates of true parameters, while fees are known with certainty. Thus, intuition suggests that fees should be given more weight than sample returns. We formalize this intuition, and derive the optimal overweighting of fees. We show that the resulting generalized performance measures are better predictors of future net performance than the standard performance measures, and they better explain future fund flows

(Not) Higher, Stronger or Swifter: Representation of Female Olympic Athletes in the Israeli Press

Despite the IOC declaration of intent for gender equality in sport and in light of the fact that a greater number of women are participating in the Olympic Games covert connotations are hidden behind the distorted and biased image presented of female athletes in the press. The current study asks whether the size and extent of coverage really matter; does more extensive coverage necessarily mean equal and true representation of women in sport, or are we getting more of the same? The findings in this study indicate two parallel processes in terms of article content: First, the greater the number of articles, the more stereotypical and biased the content becomes. Secondly, over the years, representation of female athletes has become increasingly negative and biased. Over the three Olympic Games examined (1996, 2000, 2004), female athletes were presented in a biased and stereotypical ways in relative to male athletes. The change in coverage over the years has proven to be a tendency to stereotypically present female athletes in a more negative light in comparison to male athletes

Herding, Heterogeneity, and Momentum Trading of Institutional Investors Across Asset Classes

This paper examines herding, heterogeneity, and momentum trading of institutional investors in Israel across a broad variety of financial assets. While previous studies typically focus on stocks only, we examine herding patterns, heterogeneity, and momentum trading of institutional investors in five asset classes. We find that during the sample period (1/2002 – 12/2011) large investors tended to herd more than medium and small-size investors. In contrast, small investors used momentum trading patterns more than medium and large-size investors. Homogeneity was found among large investors, especially pension funds, and during the first half of the 2000s, when investors purchased corporate bonds at the expense of government bonds. This phenomenon ended upon the beginning of the subprime crisis and against the backdrop of the financial difficulties of the bond issuers. In those years, panicked investors withdrew funds from the most liquid institutions (study funds), while infusing funds to pension and provident funds due to legally binding arrangements. We attribute some of the heterogeneous trading of the institutional investors, to those factors

Does Our World “weigh” Less Right Now? The Gravitational Pull in a Scientific Collaboration Network is Getting Weaker with Time

We study the geographical patterns of scientific collaboration from a large sample of research papers and letters written by two authors that appeared in the magazine Nature over two sub-periods, before and after the popularization of Internet use. We report three results: First, the distance distribution of co-authors is fat-tailed, in agreement with other studies that find gravitational law in collaboration networks. Second, in the later period the distance distribution dominates the range of commute-distance and beyond (\u3e50km), which renders the city the atomic unit for statistical testing. Last, strong geographical clustering remains a major generative factor in this network. Assuming the universality of this law, we estimate the gravitational constant from the pull between scientists in the network. We find that this constant has decreased two-fold over the last three decades while the other coefficients remain stable. This may indicate that the gravitational constant absorbs changes in the environment that render distances easier to cross, namely a “lighter world

Prolonged Fever, Hepatosplenomegaly, and Pancytopenia in a 46-Year-Old Woman

Liran Levy and colleagues discuss the differential diagnosis, investigation, and management of a 46-year-old woman with fever, weakness, night sweats, and weight loss