Overconfidence, optimism and entrepreneurship

Overconfidence is one of the alleged drivers for market entry. However, establishing its effect is challenging and much of the existing entrepreneurship literature confusingly conflates overconfidence with optimism. In the present study, we use validated scales to analyze the relationship between overconfidence and two important aspects of entrepreneurship, while explicitly controlling for optimism. Specifically, we study the role of overconfidence in developing intentions about entering entrepreneurship as well as how overconfidence relates to entrepreneurial orientation. Our findings show that overconfidence is related to intended market entry but not to the market position (entrepreneurial orientation) of the business

Attention-Deficit Hyperactivity Disorder Symptoms and Entrepreneurial Orientation: A Replication Note

There is a small body of literature linking attention-deficit hyperactivity disorder (ADHD) and its symptoms to entrepreneurial manifestations. Some studies take a subclinical perspective by studying the presence of symptoms, while other studies take a clinical perspective by studying the formal diagnosis of ADHD. The entrepreneurial manifestations examined range from entrepreneurial intention to the choice to become self-employed and from entrepreneurial orientation (EO) to entrepreneurial success. Despite its prominence in the entrepreneurship literature, to date only one study tested for a link with EO. The present study aims to replicate the relationship between ADHD symptoms and EO using a large data set of French small business owners. We do so by discriminating between the two dimensions of ADHD, namely attention-deficit and hyperactivity, as well as the three dimensions of EO, namely innovativeness, proactiveness, and risk-taking. We do not find a link between ADHD and EO, although we do find a positive link between ADHD and the risk-taking subdimension of EO. Hyperactivity symptoms are positively related to EO, which is mainly driven by the subdimensions proactiveness and risk-taking. We do not find a link between attention-deficit symptoms and EO, though there is a negative link between attention-deficit and proactiveness

Narcissism and entrepreneurship: Evidence from six datasets

Widespread attention is being paid to the alleged rise of narcissism in people in general and business leaders in particular. Surprisingly, hardly any studies have focused on the link between narcissism and entrepreneurship. Using self-reported data from 4798 respondents from three countries, we explore the associations between trait narcissism and six different entrepreneurial aspects that represent the entire entrepreneurial process. Overall, our findings suggest that a positive link exists between narcissism and entrepreneurship that is particularly salient in the early stage of the entrepreneurial process (e.g., entrepreneurial intention) and in the individual aspects of entrepreneurship (e.g., entrepreneurial orientation, well-being of the entrepreneur). Our additional analyses reveal that the adaptive aspect of narcissism (i.e., leadership/authority) is most consistently linked to entrepreneurship and that the links between narcissism and entrepreneurship are predominately linear. Finally, our findings are largely robust when different sets of controls are added

Hygiene and Social Distancing as Distinct Public Health Related Behaviours Among University Students During the COVID-19 Pandemic

Prevailing research on individuals’ compliance with public health related behaviours during the COVID-19 pandemic tends to study composite measures of multiple types of behaviours, without distinguishing between different types of behaviours. However, measures taken by governments involve adjustments concerning a range of different daily behaviours. In this study, we seek to explain students’ public heal

Ground observations of a space laser for the assessment of its in-orbit performance

The wind mission Aeolus of the European Space Agency was a groundbreaking achievement for Earth observation. Between 2018 and 2023, the space-borne lidar instrument ALADIN onboard the Aeolus satellite measured atmospheric wind profiles with global coverage which contributed to improving the accuracy of numerical weather prediction. The precision of the wind observations, however, declined over the course of the mission due to a progressive loss of the atmospheric backscatter signal. The analysis of the root cause was supported by the Pierre Auger Observatory in Argentina whose fluorescence detector registered the ultraviolet laser pulses emitted from the instrument in space, thereby offering an estimation of the laser energy at the exit of the instrument for several days in 2019, 2020 and 2021. The reconstruction of the laser beam not only allowed for an independent assessment of the Aeolus performance, but also helped to improve the accuracy in the determination of the laser beam's ground track on single pulse level. The results presented in this paper set a precedent for the monitoring of space lasers by ground-based telescopes and open new possibilities for the calibration of cosmic-ray observatories.Comment: 10 pages, 10 figure

Search for photons above 10 19 eV with the surface detector of the Pierre Auger Observatory

We use the surface detector of the Pierre Auger Observatory to search for air showers initiated by photons with an energy above 10$^{19}$ eV. Photons in the zenith angle range from 30∘ to 60∘ can be identified in the overwhelming background of showers initiated by charged cosmic rays through the broader time structure of the signals induced in the water-Cherenkov detectors of the array and the steeper lateral distribution of shower particles reaching ground. Applying the search method to data collected between January 2004 and June 2020, upper limits at 95% CL are set to an E$^{-2}$ diffuse flux of ultra-high energy photons above 10$^{19}$ eV, 2 × 10$^{19}$ eV and 4 × 10$^{19}$ eV amounting to 2.11 × 10$^{-3}$, 3.12 × 10$^{-4}$ and 1.72 × 10$^{-4}$ km$^{-2}$ sr$^{-1}$ yr$^{-1}$, respectively. While the sensitivity of the present search around 2 × 10$^{19}$ eV approaches expectations of cosmogenic photon fluxes in the case of a pure-proton composition, it is one order of magnitude above those from more realistic mixed-composition models. The inferred limits have also implications for the search of super-heavy dark matter that are discussed and illustrated

The energy spectrum of cosmic rays beyond the turn-down around 10¹⁷ eV as measured with the surface detector of the Pierre Auger Observatory

We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays

Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory

A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV ≡ 10¹⁸ eV). Despite the flux of these particles being extremely low, the area of ∼3000 km² covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultra-high-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of 122,000 km² sr yr, and search it for anisotropies over the 3.4π steradians covered with the Observatory. Evidence for a deviation in excess of isotropy at intermediate angular scales, with ∼15° Gaussian spread or ∼25° top-hat radius, is obtained at the 4σ significance level for cosmic-ray energies above ∼40 EeV

A Search for Photons with Energies Above 2 × 1017^{17} eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory

Ultra-high-energy photons with energies exceeding 10$^{17}$ eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 10$^{15}$ eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 10$^{17}$ eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 10$^{17}$ and 10$^{18}$ eV

Radio Measurements of the Depth of Air-Shower Maximum at the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest array of radio antenna stations deployed for the detection of cosmic rays, spanning an area of $17$ km$^2$ with 153 radio stations. It detects the radio emission of extensive air showers produced by cosmic rays in the $30-80$ MHz band. Here, we report the AERA measurements of the depth of the shower maximum ($X_\text{max}$), a probe for mass composition, at cosmic-ray energies between $10^{17.5}$ to $10^{18.8}$ eV, which show agreement with earlier measurements with the fluorescence technique at the Pierre Auger Observatory. We show advancements in the method for radio $X_\text{max}$ reconstruction by comparison to dedicated sets of CORSIKA/CoREAS air-shower simulations, including steps of reconstruction-bias identification and correction, which is of particular importance for irregular or sparse radio arrays. Using the largest set of radio air-shower measurements to date, we show the radio $X_\text{max}$ resolution as a function of energy, reaching a resolution better than $15$ g cm$^{-2}$ at the highest energies, demonstrating that radio $X_\text{max}$ measurements are competitive with the established high-precision fluorescence technique. In addition, we developed a procedure for performing an extensive data-driven study of systematic uncertainties, including the effects of acceptance bias, reconstruction bias, and the investigation of possible residual biases. These results have been cross-checked with air showers measured independently with both the radio and fluorescence techniques, a setup unique to the Pierre Auger Observatory.Comment: Submitted to Phys. Rev.