Miracle-dz/UniFAR-FTUs huggingface dataset:
IC 4499 revised: Spectro-photometric evidence of small light-element variations

It has been suggested that IC 4499 is one of the very few old globulars to not host multiple populations with light-element variations. To follow-up on this very interesting result, here we have made use of accurate HST photometry and FLAMES at VLT high-resolution spectroscopy to investigate in more detail the stellar population properties of this system. We find that the red giant branch of the cluster is clearly bimodal in near-UV-optical colour-magnitude diagrams, thus suggesting that IC 4499 is actually composed by two sub-populations of stars with different nitrogen abundances. This represents the first detection of multiple populations in IC 4499. Consistently, we also find that one star out of six is Na-rich to some extent, while we do not detect any evidence of intrinsic spread in both Mg and O. The number ratio between stars with normal and enriched nitrogen is in good agreement with the number ratio – mass trend observed in Galactic globular clusters. Also, as typically found in other systems, nitrogen rich stars are more centrally concentrated than normal stars, although this result cannot be considered conclusive because of the limited field of view covered by our observations (∼1rh). On the contrary, we observe that both the RGB UV colour spread, which is a proxy of N variations, and Na abundance variations, are significantly smaller than those observed in Milky Way globular clusters with mass and metallicity comparable to IC 4499. The modest N and Na spreads observed in this system can be tentatively connected to the fact that IC 4499 likely formed in a disrupted dwarf galaxy orbiting the Milky Way, as previously proposed based on its orbit.
Hubble Constant from LSST Strong-lens Time Delays with Microlensing Systematics

Strong-lens time delays have been widely used in cosmological studies, especially to infer H0. The upcoming LSST will provide several hundred well-measured time delays from the light curves of lensed quasars. However, due to the inclination of the finite AGN accretion disk and the differential magnification of the coherent temperature fluctuations, the microlensing by the stars can lead to changes in the actual time delay on the light-crossing timescale of the emission region of ∼days. We first study how this would change the uncertainty of H0 in the LSST era, assuming the microlensing time delays can be well estimated. We adopt 1/3, 1, and 3 days respectively as the typical microlensing time-delay uncertainties. The relative uncertainty of H0 will be enlarged to 0.47%, 0.51%, and 0.76%, from the uncertainty without the microlensing, impact 0.45%. Then, due to our lack of understanding of the quasar models and microlensing patterns, we also test the reliability of the results if one neglects this effect in the analysis. The biases of H0 will be 0.12%, 0.22% and 0.70%, suggesting that 1 day is the cutoff for a robust H0 estimate.
Does creative coursework predict educational, career, and community engagement outcomes for arts alumni?

ABSTRACT This study explores how exposure to creative coursework during one’s education can influence a variety of educational, career, and community involvement outcomes for arts alumni. Data were drawn from over 40,000 undergraduate-level arts alumni from the 2015, 2016, and 2017 administrations of the Strategic National Arts Alumni Project (SNAAP). A series of ordinary least squares and binary logistic regression models (controlling for relevant demographic characteristics) suggest that exposure to creative coursework is a significant predictor of several desirable outcomes. Specifically, the analyses suggest significant effects for exposure to creative coursework on the following: creative skills gained during time at institution, sense of connection to one’s institution, time until first job after graduation, relevance of first job after graduation, relevance of training to current occupation, current income, current occupational field, and arts community involvement. However, the magnitude of these effects was often small, and limitations are discussed. Overall, these findings can help to support curricular changes that encourage the increased use of creative activities and assignments in higher education, as well as provide accountability evidence for the effectiveness of arts education across a variety of outcomes.
Constraints on the existence of dark matter haloes by the M81 group and the Hickson compact groups of galaxies

According to the standard model of cosmology the visible, baryonic matter of galaxies is embedded in dark matter haloes, thus extending the mass and the size of galaxies by one to two orders of magnitude. Taking into account dynamical friction between the dark matter haloes, the nearby located M81 group of galaxies as well as the Hickson compact groups of galaxies are here investigated with regard to their dynamical behaviour. The results of the employment of the Markov Chain Monte Carlo method and the genetic algorithm show statistically substantial merger rates between galaxies, and long living constellations without merging galaxies comprise - apart from very few instances - initially unbound systems only. This result is derived based on three- and four-body calculations for a model of rigid Navarro-Frenk-White profiles for the dark matter haloes, but verified by the comparison to randomly chosen individual solutions for the M81 galaxy group with high-resolution simulations of live self-consistent systems (N-body calculations). In consequence, the observed compact configurations of major galaxies are a very unlikely occurence if dark matter haloes exist.
Fingerprint-guided three-dimensional skin thickness key

Since the human body has its own unique biological characteristics, such as fingerprints, faces, voices, etc., the biological characteristics of the human body are widely used as a key for image or information encryption to improve the security of the system. However, the biological characteristics of the human body are abused, resulting in reduced safety. In addition, the double random phase template is widely used as the key in optical image encryption technology. However, the linear nature of the double random phase template is vulnerable to attack. Therefore, there is an urgent need to develop a new type of key with high security and not easy to be attacked. In this article, we propose a three-dimensional skin thickness key based on fingerprint guidance. The key generation algorithm includes three steps. First, the convolutional neural network is used to segment the upper and lower boundaries of the epidermal layer in optical coherence tomography (OCT) images of the fingertip skin cross-section, and the deep learning algorithm is used to extract the maximum intensity projection (MIP) image of the internal fingerprint at the fingertip skin epidermis-dermis junction (DEJ). Secondly, by locating some areas in the MIP, the thickness of the upper and lower borders of the skin of part of the fingertips is calculated and converted into a thickness map. Finally, based on the characteristics of the internal fingerprint, the thickness map is selected as the key to encrypt the optical image. The experimental results show that the thickness of the skin of each person's fingertips is different under normal conditions, and the thickness of the skin can be encrypted as important biometric information. Numerical simulation verifies the feasibility, security and robustness of the encryption scheme.
BB mode spectrum of CMB and Inflation

Quantum effect on the BB-mode correlation spectrum of Cosmic Microwave Background for several inflation models is studied with the BICEP2/Keck Array and Planck joint data. The results do not rule out either single or multi field models of slow-roll inflation. The quantum effect is found more prominent for the inflation models with larger values of tensor-to-scalar ratio and smaller values of tensor spectral index.
Positive representations of a class of complex measures

We study the problem of constructing positive representations of complex measures. In this paper we consider complex densities on a direct product of U(1) groups and look for representations by probability distributions on the complexification of those groups. After identifying general necessary and sufficient conditions we propose several concrete realizations. Finally we study some of those realizations in examples representing problems in abelian lattice gauge theories.
Modeling Charmonium-$\eta$ Decays of $J^{PC}=1^{--}$ Higher Charmonia

We propose a new model to create a light meson in the heavy quarkonium transition, which is inspired by the Nambu$-$Jona-Lasinio (NJL) model. Hadronic transitions of $J^{PC}=1^{--}$ higher charmonia with the emission of an $\eta$ meson are studied in the framework of the proposed model. The model shows its potential to reproduce the observed decay widths and make predictions for the unobserved channels. We present our predictions for the decay width of $\Psi \to J/\psi \eta$ and $\Psi \to h_{c}(1P)\eta$, where $\Psi$ are higher $S$ and $D$ wave vector charmonia, which provide useful references to search for higher charmonia and determine their properties in forthcoming experiments. The predicted branching fraction $\mathcal B(\psi(4415)\to h_{c}(1P)\eta)=4.62\times 10^{-4}$ is one order of magnitude smaller than the $J/\psi \eta$ channel. Estimates of partial decay width $\Gamma(Y \to J/\psi \eta)$ are given for $Y(4360)$, $Y(4390)$ and $Y(4660)$ by assuming them as $c\bar{c}$ bound states with quantum numbers $3 ^3D_1$, $3 ^3D_1$ and $5 ^3S_1$, respectively. Our results are in favor of these assignments for $Y(4360)$ and $Y(4660)$. The corresponding experimental data for these $Y$ states has large statistical errors which do not provide any constraint on the mixing angle if we introduce $S-D$ mixing. To identify $Y(4390)$, precise measurements on its hadronic branching fraction are required which are eagerly awaited from BESIII.
Ricci flow on cone surfaces and a three-dimensional expanding soliton

The main objective of this thesis is the study of the evolution under the Ricci flow of surfaces with singularities of cone type. A second objective, emerged from the techniques we use, is the study of families of Ricci flow solitons in dimension 2 and 3. The Ricci flow is an evolution equation for Riemannian manifolds, introduced by R. Hamilton in 1982. It is from the achievements made by G. Perelman with this technique in 2002 when the Ricci flow has been established in a discipline itself, generating a great interest in the community. This thesis contains four original results. First result is a complete classification of solitons in smooth and cone surfaces. This classification completes the preceding results found by Hamilton, Chow and Wu and others, and we obtain explicit descriptions of all solitons in dimension 2. Second result is a Geometrization of cone surfaces by Ricci flow. This result, which uses the aforementioned first result, extends the theory of Hamilton to the singular case. This is the most comprehensive result in the thesis, for which we use and develop analysis and PDE techniques, as well as comparison geometry techniques. Third result is the existence of a Ricci flow that removes cone singularities. This clearly exposes the non-uniqueness of solutions to the flow , in analogy to the Ricci flow with cusps of P. Topping. The fourth result is the construction of a new expanding gradient Ricci soliton in dimension 3. Just as we do with solitons on cone surfaces, we give an explicit construction using techniques of phase portraits. We also prove that this is the only soliton with its topology and its lower bound of the curvature, and besides this is a critical case amongst all expanding solitons in dimension 3 with curvature bounded below.
A method of analytic centers for quadratically constrained convex quadratic programs

An interior point method is developed for maximizing a concave quadratic function under convex quadratic constraints. The algorithm constructs a sequence of nested convex sets and finds their approximate centers using a partial Newton step. Given the first convex set and its approximate center, the total arithmetic operations required to converge to an approximate solution are of order $O(\sqrt m (m + n)n^2 \ln \varepsilon )$, where m is the number of constraints, n is the number of variables, and $\varepsilon $ is determined by the desired tolerance of the optimal value and the size of the first convex set. A method to initialize the algorithm is also proposed so that the algorithm can start from an arbitrary (perhaps infeasible) point.
An Examination of Factors Predicting College Connectedness During a National Pandemic

The feeling of connectedness with others in society reduces suicide, improves well-being, and enhances effective learning (Jones et al., 2022; Jorgenson et al., 2018). This study examined possible variables contributing to campus connectedness (CC) among students and if such connectedness decreased during the COVID-19 pandemic. We hypothesized that emotional stability, self-efficacy for initiating conversation, extraversion, and participation in an honor society would positively predict CC. We also expected CC scores to decrease due to the COVID-19 pandemic. To test these hypotheses, we distributed an online questionnaire to Orange Coast College students as part of the 2021-22 Psi Beta National Research Project. Measures included Campus Connectedness, Interpersonal Communication Efficacy Scales, and the Ten Item Personality Inventory (TIPI). The project received 1,412 useful responses from community college students nationwide. First, a comparison of CC scores from the current questionnaire and a pre-pandemic study found a decrease in CC. Next, multiple regression analysis indicated that all hypothesized variables, except extraversion, were significant predictors for CC, collectively accounting for approximately 15% of CC variability. Further regression analyses revealed that self-efficacy for initiating conversation significantly mediated the relationship between extraversion and CC. Lastly, participation in an honor society significantly increased CC. Based on our findings, colleges may want to find ways to increase campus connectedness by helping students increase their confidence in initiating conversation and encouraging them to participate in honor societies or other campus organizations.
Correlation and relaxation effects in ns2-nsnp transitions

The possibility of using multiple orbitals with the same quantum numbers has been added to a multiconfiguration Dirac-Fock program. This is used to describe the relaxations when several states are computed simultaneously. As an application, the calculation of ns2-nsnp radiative transition rates in neutral atoms is presented.
Subradiance-enhanced excitation transfer between dipole-coupled nanorings of quantum emitters

A ring of sub-wavelength spaced dipole-coupled quantum emitters possesses only few radiant but many extraordinarily subradiant collective modes. These exhibit a 3D-confined spatial radiation field pattern forming a nano-scale high-Q optical resonator. We show that tailoring the geometry, orientation and distance between two such rings allows for increasing the ratio of coherent ring-to-ring coupling versus free-space emission by several orders of magnitude. In particular we find that subradiant excitations, when delocalized over several ring sites, are effectively transported between the rings with a high fidelity.
Expansive components in H II regions

We study the presence of low intensity high velocity components, which we have termed wing features in the integrated Hα emission line profiles of the H  region populations of the spiral barred galaxies NGC 1530, NGC 3359 and NGC 6951. We find that more than a third of the H  region line profiles in each galaxy show these components. The highest fraction is obtained in the galaxy whose line profiles show the best S:N, which suggests that wing features of this type may well exist in most, if not all, H  region line profiles. Applying selection criteria to the wing features, we obtain a sample of H  regions with clearly defined high velocity components in their profiles. Deconvolution of a representative sample of the line profiles eliminates any doubt that the wing features could possibly be due to instrumental effects. We present an analysis of the high velocity low intensity features fitting them with Gaussian functions; the emission measures, central velocities and velocity dispersions for the red and blue features take similar values. We interpret the features as signatures of expanding shells inside the H  regions. Up to a shell radius of Rshell ∼ 0.2 Rreg, the stellar winds from the central ionizing stars appear to satisfy the energy and momentum requirements for the formation and driving the shell. Several examples of the most luminous H  regions show that the shells appear to have larger radii; in these cases additional mechanisms may well be needed to explain the kinetic energies and momenta of the shells.
Acid Tar Waste Beneficiation Through Blending with Coal

The possibility of blending acid tar waste with coal as a beneficiation method was explored in this work. It was essential to first establish the material properties of the acid tar and coal samples together with that of the blends in terms of proximate analyses. The acid tar waste to coal blending ratios of 3:1, 1:1 and 1:3 were used. It was observed that acid tar waste exhibited high volatile and moisture content with low ash and carbon content when compared with coal. When compared with coal; a 3:1 blending ratio exhibited 56.9 % and 7.6 % reduction in ash and fixed carbon respectively and on the contrary a 38.1 % increase in volatile matter was observed. An opposite trend was obtained with 1:3 blend ratio. The 1:1 blend ratio was found to decrease the volatile and ash content by 8.3 % and 52.7 % respectively whilst fixed carbon boosted by 4.2 %. The choice for the blending ratio to apply is a trade-off between fixed carbon and volatile matter. If volatile matter is of any significance then a 3:1 mixture would be ideal; such a mixture will aid in easier ignition of coal. On the other hand a 1:3 binary mixture yields a higher fixed carbon fraction, whose effect is to boost the calorific value of the fuel, an excellent factor for combustion. Overall however, it makes economic sense to blend coal with acid tar waste for enhancing sustainability.
Disc galaxies at z = 0 and at high redshift: an explanation of the observed evolution of damped Lya absorption systems

The analysis of disc formation in this paper is based on the White & Rees model, in which disc galaxies form by the continuous cooling and accretion of gas within a merging hierarchy of dark matter haloes. A simple Kennicutt law of star formation for discs, based on a single-fluid gravitational stability model, is introduced. Since the gas supply in the disc is regulated by infall from the surrounding halo, the gas is always maintained at a critical threshold surface density ~c, where ~coc VJR. Chemical enrichment of the discs occurs when the surrounding hot halo gas is enriched with heavy elements ejected during supernova explosions. This gas then cools on to the disc, producing a new generation of metal-rich stars. We show that models of this type can reproduce many of the observed properties of a typical spiral galaxy like the Milky Way, including its gas and stellar surface density profiles and the observed relationship between the ages and metalUcities of solar neighbourhood stars. In particular, we find that the rapid early enrichment predicted by our model solves the classic G-dwarf problem. In addition, we are able to account for some of the global trends in the properties of disc galaxies, such as the observed relation between galaxy luminosity, metallicity and gas content. We then use our models to make inferences about the properties of disc galaxies at high redshift. Because the overall mass distribution in the Universe shifts to smaller haloes at higher redshifts, and these smaller haloes contain less luminous, more gas-rich galaxies, we find that the total neutral hydrogen density n (H I) increases at higher z. The predicted increase is mild, but is roughly consistent with the latest derivation of n (H I) as a function of z by Storrie-Lombardi & MacMahon. Our models are also able to account for some of the other trends seen in the high­ redshift data, including the increase in the number of high-column-density systems at high redshift, as well as the metallicity distribution of damped Lya systems at z '" 2-3. Finally, one completely general prediction of these models is that, at high redshift, the galaxies that produce the damped Lya absorption will typically be smaller, more compact and less luminous than disc galaxies at the present epoch.
Minimum variance free wave identification: Application to Cluster electric field data in the magnetosheath

The electric field measurements provided by the EFW instrument on board Cluster spacecraft are used to identify the mode of plasma waves observed in the magnetosheath. Previous identifications of magnetosheath wave modes have involved either the use of dimensionless transport ratios (DR) calculated using magnetic field and plasma parameters or the use of magnetic field measurements together with a Minimum Variance (MV) analysis. However, by utilising simultaneous four point measurements it is possible to identify the observed wave dispersion without having to resort to the use of either the calculations of DR or MV. It is, therefore, possible to identify the mode of the observed waves using measurements of any parameter (electric field, density etc.). In the present paper low frequency waves observed in the electric field by Cluster spacecraft travelling through the magnetosheath are studied. The wave dispersion relation obtained from the data indicates that observed waves are mirror waves.
Measuring Mass Concentrations and Estimating Density Contour Clusters-An Excess Mass Approach

By using empirical process theory, the so-called excess mass approach is studied. It can be applied to various statistical problems, especially in higher dimensions, such as testing for multimodality, estimating density contour clusters, estimating nonlinear functionals of a density, density estimation, regression problems and spectral analysis. We mainly consider the problems of testing for multimodality and estimating density contour clusters, but the other problems also are discussed. The excess mass (over C) is defined as a supremum of a certain functional defined on C, where C is a class of subsets of the d-dimensional Euclidean space. Comparing excess masses over different classes C yields information about the modality of the underlying probability measure F. This can be used to construct tests for multimodality. If F has a density f, the maximizing sets of the excess mass are level sets or density contour clusters of f, provided they lie in C. The excess mass and the density contour clusters can be estimated from the data. Asymptotic properties of these estimators and of the test statistics are studied for general classes C, including the classes of balls, ellipsoids and convex sets.
Observations of Magnetic Reconnection in the Transition Region of Quasi‐Parallel Shocks

Using observations of Earth's bow shock by the Magnetospheric Multiscale mission, we show for the first time that active magnetic reconnection is occurring at current sheets embedded within the quasi‐parallel shock's transition layer. We observe an electron jet and heating but no ion response, suggesting we have observed an electron‐only mode. The lack of ion response is consistent with simulations showing reconnection onset on sub‐ion time scales. We also discuss the impact of electron heating in shocks via reconnection.