National Research University – Higher School of Economics

About: National Research University – Higher School of Economics is a education organization based out in Moscow, Russia. It is known for research contribution in the topics: Population & Politics. The organization has 12873 authors who have published 23376 publications receiving 256396 citations.

Cavity-Enhanced and Ultrafast Superconducting Single-Photon Detectors

Abstract: Ultrafast single-photon detectors with high efficiency are of utmost importance for many applications in the context of integrated quantum photonic circuits. Detectors based on superconductor nanowires attached to optical waveguides are particularly appealing for this purpose. However, their speed is limited because the required high absorption efficiency necessitates long nanowires deposited on top of the waveguide. This enhances the kinetic inductance and makes the detectors slow. Here, we solve this problem by aligning the nanowire, contrary to usual choice, perpendicular to the waveguide to realize devices with a length below 1 μm. By integrating the nanowire into a photonic crystal cavity, we recover high absorption efficiency, thus enhancing the detection efficiency by more than an order of magnitude. Our cavity enhanced superconducting nanowire detectors are fully embedded in silicon nanophotonic circuits and efficiently detect single photons at telecom wavelengths. The detectors possess subnanosec...

Choosing the number of clusters

Abstract: The issue of determining ‘the right number of clusters’ is attracting ever growing interest. The paper reviews published work on the issue with respect to mixture of distributions, partition, especially in k-means clustering, and hierarchical cluster structures. Some perspective directions for further developments are outlined.

Sensitive Topics in PC Web and Mobile Web Surveys: Is There a Difference?

Abstract: A large number of findings in survey research suggest that misreporting in sensitive questions is situational and can vary in relation to context. The methodological literature demonstrates that social desirability biases are less prevalent in self-administered surveys, particularly in Web surveys, when there is no interviewer and less risk of presenting oneself in an unfavorable light. Since there is a growing number of users of mobile Web browsers, we focused our study on the effects of different devices (PC or cell phone) in Web surveys on the respondents’ willingness to report sensitive information. To reduce selection bias, we carried out a two-wave cross-over experiment using a volunteer online access-panel in Russia. Participants were asked to complete the questionnaire in both survey modes: PC and mobile Web survey. We hypothesized that features of mobile Web usage may affect response accuracy and lead to more socially desirable responses compared to the PC Web survey mode. We found significant differences in the reporting of alcohol consumption by mode, consistent with our hypothesis. But other sensitive questions did not show similar effects. We also found that the presence of familiar bystanders had an impact on the responses, while the presence of strangers did not have any significant effect in either survey mode. Contrary to expectations, we did not find evidence of a positive impact of completing the questionnaire at home and trust in data confidentiality on the level of reporting. These results could help survey practitioners to design and improve data quality in Web surveys completed on different devices.

Ecological and cultural factors underlying the global distribution of prejudice

Abstract: Prejudiced attitudes and political nationalism vary widely around the world, but there has been little research on what predicts this variation. Here we examine the ecological and cultural factors underlying the worldwide distribution of prejudice. We suggest that cultures grow more prejudiced when they tighten cultural norms in response to destabilizing ecological threats. A set of seven archival analyses, surveys, and experiments (∑N = 3,986,402) find that nations, American states, and pre-industrial societies with tighter cultural norms show the most prejudice based on skin color, religion, nationality, and sexuality, and that tightness predicts why prejudice is often highest in areas of the world with histories of ecological threat. People's support for cultural tightness also mediates the link between perceived ecological threat and intentions to vote for nationalist politicians. Results replicate when controlling for economic development, inequality, conservatism, residential mobility, and shared cultural heritage. These findings offer a cultural evolutionary perspective on prejudice, with implications for immigration, intercultural conflict, and radicalization.

Fermions and supersymmetry in E6(6) exceptional field theory

Abstract: We construct the supersymmetric completion of E6(6)-covariant exceptional field theory. The theory is based on a (5 + 27)-dimensional generalized space-time subject to a covariant section constraint. The fermions are tensors under the local Lorentz group SO(1, 4) × USp(8) and transform as weighted scalars under the E6(6) (internal) generalized diffeomorphisms. We present the complete Lagrangian and prove its invariance under supersymmetry. Upon explicit solution of the section constraint the theory embeds full D = 11 supergravity and IIB supergravity, respectively.