The defect variance of random spherical harmonics

The defect of a function $f:M\rightarrow \mathbb{R}$ is defined as the difference between the measure of the positive and negative regions. In this paper, we begin the analysis of the distribution of defect of random Gaussian spherical harmonics. By an easy argument, the defect is non-trivial only for even degree and the expected value always vanishes. Our principal result is obtaining the asymptotic shape of the defect variance, in the high frequency limit. As other geometric functionals of random eigenfunctions, the defect may be used as a tool to probe the statistical properties of spherical random fields, a topic of great interest for modern Cosmological data analysis.Comment: 19 page

Spin Needlets for Cosmic Microwave Background Polarization Data Analysis

Scalar wavelets have been used extensively in the analysis of Cosmic Microwave Background (CMB) temperature maps. Spin needlets are a new form of (spin) wavelets which were introduced in the mathematical literature by Geller and Marinucci (2008) as a tool for the analysis of spin random fields. Here we adopt the spin needlet approach for the analysis of CMB polarization measurements. The outcome of experiments measuring the polarization of the CMB are maps of the Stokes Q and U parameters which are spin 2 quantities. Here we discuss how to transform these spin 2 maps into spin 2 needlet coefficients and outline briefly how these coefficients can be used in the analysis of CMB polarization data. We review the most important properties of spin needlets, such as localization in pixel and harmonic space and asymptotic uncorrelation. We discuss several statistical applications, including the relation of angular power spectra to the needlet coefficients, testing for non-Gaussianity on polarization data, and reconstruction of the E and B scalar maps.Comment: Accepted for publication in Phys. Rev.

NGC 1068: No change in the mid-IR torus structure despite X-ray variability

Context. Recent NuSTAR observations revealed a somewhat unexpected increase in the X-ray flux of the nucleus of NGC 1068. We expect the infrared emission of the dusty torus to react on the intrinsic changes of the accretion disk. Aims. We aim to investigate the origin of the X-ray variation by investigating the response of the mid-infrared environment. Methods. We obtained single-aperture and interferometric mid-infrared measurements and directly compared the measurements observed before and immediately after the X-ray variations. The average correlated and single-aperture fluxes as well as the differential phases were directly compared to detect a possible change in the structure of the nuclear emission on scales of $\sim$ 2 pc. Results. The flux densities and differential phases of the observations before and during the X-ray variation show no significant change over a period of ten years. Possible minor variations in the infrared emission are $\lesssim$ 8 %. Conclusions. Our results suggest that the mid-infrared environment of NGC 1068 has remained unchanged for a decade. The recent transient change in the X-rays did not cause a significant variation in the infrared emission. This independent study supports previous conclusions that stated that the X-ray variation detected by NuSTAR observations is due to X-ray emission piercing through a patchy section of the dusty region.Comment: 6 pages, 5 figures, 3 tables. Accepted for publication on A&

A needlet-based approach to the shower-mode data analysis in the ARGO-YBJ experiment

The ARGO-YBJ experiment, located at the Yangbajing Cosmic Ray Laboratory (Tibet, 4300 m a.s.l., 606 g/cm2), is an EAS-array exploiting the full coverage approach at high altitude. The large field of view (2 sr) and the low energy threshold (few hundreds of GeV) result in a trigger rate of ∼3.5kHz and ∼1011EAS collected per year. Such a data set contains signals laying on different angular scales: point-like and extended gamma-ray sources, as well as large and intermediate scale cosmic-ray anisotropies. The separation of all these contributions is crucial, mostly when they overlap with each other. Needlets are a new form of spherical wavelets that have recently drawn a lot of attention in the cosmological literature, especially in connection with the analysis of CMB data. Needlets enjoy a number of important statistical and numerical properties which suggest that they can be very effective in handling cosmic-ray and gamma-ray data analysis. An unprecedented application to astroparticle physics is shown here. In particular, we focus on their use for background estimation, which is expected to be optimal or nearly-optimal in a well-defined mathematical sense, and for point-source detection. This technique is applied here to the ARGO-YBJ data set, stressing its advantages with respect to standard methods

On Nonlinear Functionals of Random Spherical Eigenfunctions

We prove Central Limit Theorems and Stein-like bounds for the asymptotic behaviour of nonlinear functionals of spherical Gaussian eigenfunctions. Our investigation combine asymptotic analysis of higher order moments for Legendre polynomials and, in addition, recent results on Malliavin calculus and Total Variation bounds for Gaussian subordinated fields. We discuss application to geometric functionals like the Defect and invariant statistics, e.g. polyspectra of isotropic spherical random fields. Both of these have relevance for applications, especially in an astrophysical environment.Comment: 24 page

Intimate intergroup contact across the lifespan

Intergroup contact can be as casual as members of different groups walking past one another on the street or as intimate as developing cross‐group friendships or romantic relationships. To date, however, the majority of intergroup contact research has focused on examining the effects of contact through self‐report measures of interactions and friendships. While this research has made a substantial contribution to scientific understanding, less is known about how different forms of contact (casual vs. intimate) influence each other and are associated with outcomes across the lifespan. The present article focuses on intimate contact; a close and meaningful relationship or interaction with either an ingroup or outgroup member. We critically review the nature and consequences (good and bad) of intimate contact for children, youth and adults and for both majority and minority group members, focusing primarily on intimate intergroup contact. We also consider how intimate contact might be best measured in future research. Implications for research design, policy, and practice are considered

Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor, but not indoor, reared pigs

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor‐ but not the indoor‐reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano‐supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free‐range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano‐supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor‐rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality

Broadband X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292

We discuss the broadband X-ray spectrum of GRS 1734-292 obtained from non-simultaneous XMM-Newton and NuSTAR observations, performed in 2009 and 2014, respectively. GRS1734-292 is a Seyfert 1 galaxy, located near the Galactic plane at $z=0.0214$. The NuSTAR spectrum ($3-80$ keV) is dominated by a primary power-law continuum with $\Gamma=1.65 \pm 0.05$ and a high-energy cutoff $E_c=53^{+11}_{-8}$ keV, one of the lowest measured by NuSTAR in a Seyfert galaxy. Comptonization models show a temperature of the coronal plasma of $kT_e=11.9^{+1.2}_{-0.9}$ keV and an optical depth, assuming a slab geometry, $\tau=2.98^{+0.16}_{-0.19}$ or a similar temperature and $\tau=6.7^{+0.3}_{-0.4}$ assuming a spherical geometry. The 2009 XMM-Newton spectrum is well described by a flatter intrinsic continuum ($\Gamma=1.47^{+0.07}_{-0.03}$) and one absorption line due to Fe\textsc{XXV} K$\alpha$ produced by a warm absorber. Both data sets show a modest iron K$\alpha$ emission line at $6.4$ keV and the associated Compton reflection, due to reprocessing from neutral circumnuclear material