The Gravitational Polarization in General Relativity: Solution to Szekeres' Model of Quadrupole Polarization

A model for the static weak-field macroscopic medium is analyzed and the equation for the macroscopic gravitational potential is derived. This is a biharmonic equation which is a non-trivial generalization of the Poisson equation of Newtonian gravity. In case of the strong gravitational quadrupole polarization it essentially holds inside a macroscopic matter source. Outside the source the gravitational potential fades away exponentially. The equation is equivalent to a system of the Poisson equation and the nonhomogeneous modified Helmholtz equations. The general solution to this system is obtained by using Green's function method and it does not have a limit to Newtonian gravity. In case of the insignificant gravitational quadrupole polarization the equation for macroscopic gravitational potential becomes the Poisson equation with the matter density renormalized by the factor including the value of the quadrupole gravitational polarization of the source. The general solution to this equation obtained by using Green's function method has a limit to Newtonian gravity.Comment: 22 pages, no figures, to appear on Class. Quantum Gra

Additionality as a principle of European R & D funding

Abstract not availableresearch and development

Cognitive Skills Explain Economic Preferences, Strategic Behavior, and Job Attachment

Economic analysis has said little about how an individual’s cognitive skills (CS's) are related to the individual’s preferences in different choice domains, such as risk-taking or saving, and how preferences in different domains are related to each other. Using a sample of 1,000 trainee truckers we report three findings. First, we show a strong and significant relationship between an individual’s cognitive skills and preferences, and between the preferences in different choice domains. The latter relationship may be counterintuitive: a patient individual, more inclined to save, is also more willing to take calculated risks. A second finding is that measures of cognitive skill predict social awareness and choices in a sequential Prisoner's Dilemma game. Subjects with higher CS's more accurately forecast others' behavior, and differentiate their behavior depending on the first mover’s choice, returning higher amount for a higher transfer, and lower for a lower one. After controlling for investment motives, subjects with higher CS’s also cooperate more as first movers. A third finding concerns on-the-job choices. Our subjects incur a significant financial debt for their training that is forgiven only after twelve months of service. Yet over half leave within the first year, and cognitive skills are also strong predictors of who exits too early, stronger than any other social, economic and personality measure in our data. These results suggest that cognitive skills affect the economic lives of individuals, by systematically changing preferences and choices in a way that favors the economic success of individuals with higher cognitive skills.field experiment, risk aversion, ambiguity aversion, loss aversion, time preference, Prisoners Dilemma, social dilemma, IQ, MPQ, numeracy, U.S. trucking industry, for-hire carriage, truckload (TL), driver turnover, employment duration, survival model

Overconfidence is a Social Signaling Bias

Evidence from psychology and economics indicates that many individuals overestimate their ability, both absolutely and relatively. We test three different theories about observed relative overconfidence. The first theory notes that simple statistical comparisons (for example, whether the fraction of individuals rating own skill above the median value is larger than half) are compatible (Benoît and Dubra, 2007) with a Bayesian model of updating from a common prior and truthful statements. We show that such model imposes testable restrictions on relative ability judgments, and we test the restrictions. Data on 1,016 individuals' relative ability judgments about two cognitive tests rejects the Bayesian model. The second theory suggests that self-image concerns asymmetrically affect the choice to get new information about oneâs abilities, and this asymmetry produces overconfidence (Kőszegi, 2006; Weinberg, 2006). We test an important specific prediction of these models: individuals with a higher belief will be less likely to search for further information about their skill, because this information might make this belief worse. Our data also reject this prediction. The third theory is that overconfidence is induced by the desire to send positive signals to others about oneâs own skill; this suggests either a bias in judgment, strategic lying, or both. We provide evidence that personality traits strongly affect relative ability judgments in a pattern that is consistent with this third theory. Our results together suggest that overconfidence in statements is most likely to be induced by social concerns than by either of the other two factors.IQ, field experiment, social signaling, self-image, Bayesian updating, overconfidence, numeracy, personality, MPQ

Which Measures of Time Preference Best Predict Outcomes? Evidence from a Large-Scale Field Experiment

Economists and psychologists have devised numerous instruments to measure time preferences and have generated a rich literature examining the extent to which time preferences predict important outcomes; however, we still do not know which measures work best. With the help of a large sample of non-student participants (truck driver trainees) and administrative data on outcomes, we gather four different time preference measures and test the extent to which they predict both on their own and when they are all forced to compete head-to-head. Our results suggest that the now familiar (β, δ) formulation of present bias and exponential discounting predicts best, especially when both parameters are used.time preference, impatience, discounting, present bias, field experiment, trucker

Statistical Uncertainty in Quantitative Neutron Radiography

We demonstrate a novel procedure to calibrate neutron detection systems commonly used in standard neutron radiography. This calibration allows determining the uncertainties due to Poisson-like neutron counting statistics for each individual pixel of a radiographic image. The obtained statistical errors are necessary in order to perform a correct quantitative analysis. This fast and convenient method is applied to data measured at the cold neutron radiography facility ICON at the Paul Scherrer Institute. Moreover, from the results the effective neutron flux at the beam line is determined

First evidence of multiple populations along the AGB from Str\"omgren photometry

Spectroscopic studies have demonstrated that nearly all Galactic globular clusters (GCs) harbour multiple stellar populations with different chemical compositions. Moreover, colour-magnitude diagrams based exclusively on Str\"omgrem photometry have allowed us to identify and characterise multiple populations along the RGB of a large number of clusters. In this paper we show for the first time that Str\"omgren photometry is also very effcient at identifying multiple populations along the AGB, and demonstrate that the AGB of M3, M92, NGC362, NGC1851, and NGC6752 are not consistent with a single stellar population. We also provide a catalogue of RGB and AGB stars photometrically identified in these clusters for further spectroscopic follow-up studies.We combined photometry and elemental abundances from the literature for RGB and AGB stars in NGC6752 where the presence of multiple populations along the AGB has been widely debated. We find that, while the MS, SGB, and RGB host three stellar populations with different helium and light element abundances, only two populations of AGB stars are present in the cluster. These results are consistent with standard evolutionary theory.Comment: 9 pages, 3 figures, 1 table in the main article, 3 tables in the appendix of which 2 tables containing coordinates and photometry of photometrically identified RGB and AGB star