Miracle-dz/UniFAR-FTUs huggingface dataset:
K π scattering for isospin 1 2 and 3 2 in lattice QCD

We simulate $K\ensuremath{\pi}$ scattering in $s$ wave and $p$ wave for both isospins $I=1/2$, $3/2$ using quark-antiquark and meson-meson interpolating fields. We extract the elastic phase shifts $\ensuremath{\delta}$ at several values of the $K\ensuremath{\pi}$ relative momenta. The resulting phases exhibit qualitative agreement with the experimental phases in all four channels. We express the $s$-wave phase shifts near threshold in terms of the scattering length and the effective range. Our $K\ensuremath{\pi}$ system has zero total momentum and is simulated on a single ensemble with two dynamical quarks, so results apply for ${m}_{\ensuremath{\pi}}\ensuremath{\simeq}266\text{ }\text{ }\mathrm{MeV}$ and ${m}_{K}\ensuremath{\simeq}552\text{ }\text{ }\mathrm{MeV}$ in our simulation. The backtracking contractions in both $I=1/2$ channels are handled by the use of Laplacian-Heavyside smeared quarks within the distillation method. Elastic phases are extracted from the energy levels using L\"uscher's relations. In all four channels, we observe the expected $K(n)\ensuremath{\pi}(\ensuremath{-}n)$ scattering states, which are shifted due to the interaction. In both attractive $I=1/2$ channels, we observe additional states which are related to resonances; we attribute them to ${K}_{0}^{*}(1430)$ in $s$ wave and ${K}^{*}(892)$, ${K}^{*}(1410)$ and ${K}^{*}(1680)$ in $p$ wave.
Estimators for the exponent and upper limit, and goodness-of-fit tests for (truncated) power-law distributions

Many objects studied in astronomy follow a power law distribution function, for example the masses of stars or star clusters. A still used method by which such data is analysed is to generate a histogram and fit a straight line to it. The parameters obtained in this way can be severely biased, and the properties of the underlying distribution function, such as its shape or a possible upper limit, are difficult to extract. In this work we review techniques available in the literature and present newly developed (effectively) bias-free estimators for the exponent and the upper limit. The software packages are made available as downloads. Furthermore we discuss various graphical representations of the data and powerful goodness-of-fit tests to assess the validity of a power law for describing the distribution of data. As an example, we apply the presented methods to the data set of massive stars in R136 and the young star clusters in the Large Magellanic Cloud. (abridged)
MODELING THE Lyα FOREST IN COLLISIONLESS SIMULATIONS

Cosmological hydrodynamic simulations can accurately predict the properties of the intergalactic medium (IGM), but only under the condition of retaining the high spatial resolution necessary to resolve density fluctuations in the IGM. This resolution constraint prohibits simulating large volumes, such as those probed by BOSS and future surveys, like DESI and 4MOST. To overcome this limitation, we present “Iteratively Matched Statistics” (IMS), a novel method to accurately model the Lyα forest with collisionless N-body simulations, where the relevant density fluctuations are unresolved. We use a small-box, high-resolution hydrodynamic simulation to obtain the probability distribution function (PDF) and the power spectrum of the real-space Lyα forest flux. These two statistics are iteratively mapped onto a pseudo-flux field of an N-body simulation, which we construct from the matter density. We demonstrate that our method can reproduce the PDF, line of sight and 3D power spectra of the Lyα forest with good accuracy (7%, 4%, and 7% respectively). We quantify the performance of the commonly used Gaussian smoothing technique and show that it has significantly lower accuracy (20%–80%), especially for N-body simulations with achievable mean inter-particle separations in large-volume simulations. In addition, we show that IMS produces reasonable and smooth spectra, making it a powerful tool for modeling the IGM in large cosmological volumes and for producing realistic “mock” skies for Lyα forest surveys.
The Hubble diagram for a system within dark energy: the location of the zero-gravity radius and the global Hubble rate

Here we continue to discuss the principle of the local measurement of dark energy using the normalized Hubble diagram describing the environment of a system of galaxies. We calculate the present locus of test particles injected a fixed time ago (\sim the age of the universe), in the standard \Lambda -cosmology and for different values of the system parameters (the model includes a central point mass M and a local dark energy density \rho_{loc}) and discuss the position of the zero-gravity distance R_v in the Hubble diagram. Our main conclusions are: 1) When the local DE density \rho_{loc} is equal to the global DE density \rho_v, the outflow reaches the global Hubble rate at the distance R_2 = (1+z_v)R_v, where z_v is the global zero-acceleration redshift (\approx 0.7 for the standard model). This is also the radius of the ideal Einstein-Straus vacuole. 2) For a wide range of the local-to-global dark energy ratio \rho_{loc}/\rho_v, the local flow reaches the known global rate (the Hubble constant) at a distance R_2 \ga 1.5 \times R_v. Hence, R_v will be between R_2/2 and R_2, giving upper and lower limits to \rho_{loc}/M. For the Local Group, this supports the view that the local density is near the global one.
Nearly free electron states in MXenes

Using a set of first-principles calculations, we studied the electronic structures of two-dimensional transition metal carbides and nitrides, so called MXenes, functionalized with F, O, and OH. Our projected band structures and electron localization function analyses reveal the existence of nearly free electron (NFE) states in a variety of MXenes. The NFE states are spatially located just outside the atomic structure of MXenes and are extended parallel to the surfaces. Moreover, we found that the OH-terminated MXenes offer the NFE states energetically close to the Fermi level. In particular, the NFE states in some of the OH-terminated MXenes, such as $\mathrm{T}{\mathrm{i}}_{2}\mathrm{C}{(\mathrm{OH})}_{2},\mathrm{Z}{\mathrm{r}}_{2}\mathrm{C}{(\mathrm{OH})}_{2},\mathrm{Z}{\mathrm{r}}_{2}\mathrm{N}{(\mathrm{OH})}_{2},\mathrm{H}{\mathrm{f}}_{2}\mathrm{C}{(\mathrm{OH})}_{2},\mathrm{H}{\mathrm{f}}_{2}\mathrm{N}{(\mathrm{OH})}_{2},\mathrm{N}{\mathrm{b}}_{2}\mathrm{C}{(\mathrm{OH})}_{2}$, and $\mathrm{T}{\mathrm{a}}_{2}\mathrm{C}{(\mathrm{OH})}_{2}$, are partially occupied. This is in remarkable contrast to graphene, graphane, and $\mathrm{Mo}{\mathrm{S}}_{2}$, in which their NFE states are located far above the Fermi level and thus they are unoccupied. As a prototype of such systems, we investigated the electron transport properties of $\mathrm{H}{\mathrm{f}}_{2}\mathrm{C}{(\mathrm{OH})}_{2}$ and found that the NFE states in $\mathrm{H}{\mathrm{f}}_{2}\mathrm{C}{(\mathrm{OH})}_{2}$ provide almost perfect transmission channels without nuclear scattering for electron transport. Our results indicate that these systems might find applications in nanoelectronic devices. Our findings provide new insights into the unique electronic band structures of MXenes.
The Skyrme model in the BPS limit

In this review, we summarise the main features of the BPS Skyrme model which provides a physically well-motivated idealisation of atomic nuclei and nuclear matter: 1) it leads to zero binding energies for classical solitons (while realistic binding energies emerge owing to the semiclassical corrections, the Coulomb interaction and isospin breaking); 2) it describes a perfect non-barotropic fluid already at the microscopic (field theoretical) level which allows to study thermodynamics beyond the mean-field limit. These properties allow for an approximate but analytical calculation of binding energies of the most abundant nuclei, for a determination of the equation of state of skyrmionic matter (both in the full field theory and in a mean-field approximation) as well as the description of neutron stars as Skyrme solitons with a very good agreement with available observational data. All these results suggest that the proper low energy effective model of QCD should be close to the BPS Skyrme model in a certain sense (a "near-BPS Skyrme model"), with a prominent role played by the BPS part.
The Relationships between Physical Activity, Screen Time and Sleep Time According to the Adolescents’ Sex and the Day of the Week

This study had two aims: (1) to identify the levels of physical activity, screen time and sleep time of adolescents according to the sex of the participant and the day of the week; (2) to find out the relationships between physical activity, screen time and sleep time according to the sex of the participant and the day of the week. The study design was non-experimental, descriptive-correlational and cross-sectional. The sample consisted of 694 adolescents in Compulsory Secondary Education from Soria (Spain). Four by One-Day Physical Activity Questionnaires were used to measure levels of physical activity, screen time and sleep time. Levene’s test and Student’s t-test were used to calculate the difference between the means of the variables. Pearson’s test was used to calculate bivariate correlations between variables. Results showed higher levels of screen time in males (136.93 min/day ± 81.548). Screen time, sleep time and moderate–vigorous physical activity are higher during the weekend. Positive relationships were found between screen time and light physical activity (rmales = 0.274; p ≤ 0.01; rfemales = 0.065; p > 0.05). The correlations between moderate–vigorous physical activity and screen time were negative (rmales = −0.282; p ≤ 0.01; rfemales = −0.187; p ≤ 0.05). The relationship between screen time and sleep time was negative in males (r = −0.135; p ≤ 0.05). In conclusion, the levels of physical activity, screen time and sleep time vary according to the sex of the participants and the day of the week.
Global mass segregation in hydrodynamical simulations of star formation

Recent analyses of mass segregation diagnostics in star-forming regions invite a comparison with the output of hydrodynamic simulations of star formation. In this work we investigate the state of mass segregation of ‘stars’ (i.e. sink particles in the simulations) in the case of hydrodynamical simulations which omit feedback. We first discuss methods to quantify mass segregation in substructured regions, either based on the minimum spanning tree (Allison’s Λ), or through analysis of correlations between stellar mass and local stellar surface number densities. We find that the presence of even a single ‘outlier’ (i.e. a massive object far from other stars) can cause the Allison Λ method to describe the system as inversely mass segregated, even where in reality the most massive sink particles are overwhelmingly in the centres of the subclusters. We demonstrate that a variant of the Λ method is less susceptible to this tendency but also argue for an alternative representation of the data in the plane of stellar mass versus local surface number density. The hydrodynamical simulations show global mass segregation from very early times which continues throughout the simulation, being only mildly influenced during subcluster merging. We find that up to ≈2–3 per cent of the ‘massive’ sink particles (m > 2.5 M⊙) are in relative isolation because they have formed there, although other sink particles can form later in their vicinity. Ejections of massive sinks from subclusters do not contribute to the number of isolated massive sink particles, as the gravitational softening in the calculation suppresses this process.
Chaotic and stochastic processes in the accretion flows of the black hole X-ray binaries revealed by recurrence analysis

The black hole candidates exhibit fast variability of their X-ray emission on a wide range of timescales. The short, coherent variations, with frequencies above 1 Hz, are referred to as quasi-periodic oscillations, and are generally explained by resonant effects in the black hole accretion flow. The purely stochastic variability that occurs due to turbulent conditions in the plasma, is quantified by the power density spectra and appears practically in all types of sources and their spectral states. The specific kind of quasi-periodic flares is expected, when the global structure of the accretion flow, governed by the nonlinear hydrodynamics, induces fluctuations around a fixed point solution. These conditions, which occur at high accretion rates, lead to the variability in the sense of deterministic chaos. We study the nonlinear behaviour of X-ray sources using the recurrence analysis method. We estimate quantitatively the indications for deterministic chaos, such as the Renyi's entropy, for the observed time series, and we compare them with the surrogate data. Using the data collected by RXTE satellite, we reveal the oscillations pattern and the observable properties of six black hole systems. We confirm that both the well known microquasar GRS 1915+105, as well as its recently discovered analogue, IGR J17091-3624, exhibit variability characteristic to deterministic chaotic system. We conclude therefore that the underlying nature of the process must be intrinsically connected in these sources with the accretion flow instability, that leads to the limit cycle oscillations around a fixed point. Furthermore, we studied four other black hole candidates with high accretion rates. For GX 339-4, GRO J1655-40 and XTE J1550-564 we obtained significant results for some observations, whereas for XTE J1650-500 no such data set was found.
Evolution of 0. 7--3. 0 M/sub sun/ stars having -1. 0< or =(Fe/H)< or =0. 0

Five grids of stellar models have been calculated for masses ranging from 0.7 to 3.0 M/sub sun/ assuming, in turn, a metal abundance (Fe/H) = -1.0, -0.76, -0.46, -0.23, and 0.0. All of the calculations are based on a value of Y = 0.25 for the helium content and . cap alpha. = 1.6 for the ratio of the mixing length to the pressure scale height. The latest improvements in opacity data and nuclear reaction rates have been incorporated into the computations. Moreover, model atmospheres have been used to provide the boundary conditions for the stellar interior calculations as well as to transpose the isochrones, computed for ages from 0.3 x 10/sup 9/ to 15 x 10/sup 9/ yr, from the theoretical to the (M/sub v/, B-V)-plane. Cousins V-I and V-R colors are also predicted for each of the model sequences, which are extensively tabulated.
Star formation in Lynds 1641.

Star Formation in Lynds 1641 February 1996 Lori E. Allen, B.A., University of California Santa Cruz Ph.D., University of Massachusetts Amherst Directed by: Professor Karen M. Strom We conducted an extensive multi-wavelength study of the nearest giant molecular cloud, L1641, with the goal of characterizing its stellar populations. At a distance of approximately 500 pc, L1641 provides an excellent opportunity for studying star formation over the entire range of stellar masses, and the star formation history in a region thought representative of those dominating stellar production in the Milky Way. Our approach combines imaging surveys at optical and infrared wavelengths with spectroscopic surveys at AA6000 9000A to measure stellar luminosities and effective temperatures. Stellar ages and masses are then estimated from comparison of L*, Teff with pre-main sequence evolutionary tracks. The stars for which we have obtained classifiable spectra as well as optical (R, I) and near-infrared (J, H, K) photometry number ~300, and are contained within four regions, each approximately 20' square (2.5x2.5 pc). Our 2.2//m images reveal both modest aggregates of several tens of stars and stars distributed at random across the face of the cloud; we find no evidence of rich (N >> 100 stars) clusters. The aggregate members appear to have formed within the past 1 Myr, while the distributed population contains both young stars (t<l Myr) and stars ranging in age up to 30 Myr. From comparison of the fraction of the youngest stars forming in aggregates and in isolation, we conclude that stars born initially in aggregates comprise 25-50% of the total stars formed in L1641.
Disc formation from tidal disruptions of stars on eccentric orbits by Schwarzschild black holes

The potential of tidal disruption of stars to probe otherwise quiescent supermassive black holes cannot be exploited, if their dynamics is not fully understood. So far, the observational appearance of these events has been derived from analytical extrapolations of the debris dynamical properties just after disruption. By means of hydrodynamical simulations, we investigate the subsequent fallback of the stream of debris towards the black hole for stars already bound to the black hole on eccentric orbits. We demonstrate that the debris circularize due to relativistic apsidal precession which causes the stream to self-cross. The circularization timescale varies between 1 and 10 times the period of the star, being shorter for more eccentric and/or deeper encounters. This self-crossing leads to the formation of shocks that increase the thermal energy of the debris. If this thermal energy is efficiently radiated away, the debris settle in a narrow ring at the circularization radius with shock-induced luminosities of $\sim 10-10^3 \, L_{\rm Edd}$. If instead cooling is impeded, the debris form an extended torus located between the circularization radius and the semi-major axis of the star with heating rates $\sim 1-10^2 \, L_{\rm Edd}$. Extrapolating our results to parabolic orbits, we infer that circularization would occur via the same mechanism in $\sim 1$ period of the most bound debris for deeply penetrating encounters to $\sim 10$ for grazing ones. We also anticipate the same effect of the cooling efficiency on the structure of the disc with associated luminosities of $\sim 1-10 \, L_{\rm Edd}$ and heating rates of $\sim 0.1-1 \, L_{\rm Edd}$. In the latter case of inefficient cooling, we deduce a viscous timescale generally shorter than the circularization timescale. This suggests an accretion rate through the disc tracing the fallback rate, if viscosity starts acting promptly.
Kaon and pion parton distribution amplitudes to twist-three

We compute all kaon and pion parton distribution amplitudes (PDAs) to twist-three and find that only the pseudotensor PDA can reasonably be approximated by its conformal limit expression. At terrestrially accessible energy scales, the twist-two and pseudoscalar twist-three PDAs differ significantly from those functions commonly associated with their forms in QCD's conformal limit. In all amplitudes studied, SU(3) flavour-symmetry breaking is typically a 13% effect. This scale is determined by nonperturbative dynamics; namely, the current-quark-mass dependence of dynamical chiral symmetry breaking. The heavier-quark is favoured by this distortion, for example, support is shifted to the s-quark in the negative kaon. It appears, therefore, that at energy scales accessible with existing and foreseeable facilities, one may obtain reliable expectations for experimental outcomes by using these "strongly dressed" PDAs in formulae for hard exclusive processes. Following this procedure, any discrepancies between experiment and theory will be significantly smaller than those produced by using the conformal-limit PDAs. Moreover, the magnitude of any disagreement will either be a better estimate of higher-order, higher-twist effects or provide more realistic constraints on the Standard Model.
The Incidence of Immune Mediated Inflammatory Diseases Following COVID-19: a Matched Cohort Study in UK Primary Care

Abstract Objective To assess whether there is an association between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) infection and the incidence of immune mediated inflammatory diseases (IMIDs). Design Matched cohort study. Setting Primary care electronic health record data from the Clinical Practice Research Datalink Aurum database. Participants The exposed cohort included 458,147 adults aged 18 years and older with a confirmed SARS CoV-2 infection by reverse transcriptase polymerase chain reaction (RT-PCR) or lateral flow antigen test, and no prior diagnosis of IMIDs. They were matched on age, sex, and general practice to 1,818,929 adults in the unexposed cohort with no diagnosis of confirmed or suspected SARS CoV-2 infection and no prior diagnosis of IMIDs. Main Outcome Measures The primary outcome measure was a composite of the incidence of any of the following IMIDs: 1. autoimmune thyroiditis, 2. coeliac disease, 3. inflammatory bowel disease (IBD), 4. myasthenia gravis, 5. pernicious anaemia, 6. psoriasis, 7. rheumatoid arthritis (RA), 8. Sjogrens syndrome, 9. systemic lupus erythematosus (SLE), 10. type 1 diabetes mellitus (T1DM), and 11. vitiligo. The secondary outcomes were the incidence of each of these conditions separately. Cox proportional hazards models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for the primary and secondary outcomes comparing the exposed to the unexposed cohorts, and adjusting for age, sex, ethnic group, smoking status, body mass index, relevant infections, and medications. Results 537 patients (0.11%) in the exposed cohort developed an IMID during the follow-up period over 0.29 person years, giving a crude incidence rate of 3.54 per 1000 person years. This was compared 1723 patients (0.09%) over 0.29 person years in the unexposed cohort, with an incidence rate of 2.82 per 1000 person years. Patients in the exposed cohort had a 22% relative increased risk of developing an IMID, compared to the unexposed cohort (aHR 1.22, 95% CI 1.10 to 1.34). The incidence of three IMIDs were statistically significantly associated with SARS CoV-2 infection. These were T1DM (aHR 1.56, 95% CI 1.09 to 2.23), IBD (1.52, 1.23 to 1.88), and psoriasis (1.23, 1.05 to 1.42). Conclusions SARS CoV-2 was associated with an increased incidence of IMIDs including T1DM, IBD and psoriasis. Further research is needed to replicate these findings in other populations and to measure autoantibody profiles in cohorts of individuals with COVID-19, including Long COVID and matched controls.
COVID-19: Impact of Original, Gamma, Delta, and Omicron Variants of SARS-CoV-2 in Vaccinated and Unvaccinated Pregnant and Postpartum Women

This study compares the clinical characteristics and disease progression among vaccinated and unvaccinated pregnant and postpartum women who tested positive for different variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the Brazilian epidemiological data. Data of pregnant or postpartum patients testing positive for SARS-CoV-2 and presenting with coronavirus disease 2019 (COVID-19) from February 2020 to July 2022 were extracted from Brazilian national database. The patients were grouped based on vaccination status and viral variant (original, Gamma, Delta, and Omicron variants), and their demographics, clinical characteristics, comorbidities, symptoms, and outcomes were compared retrospectively. Data of 10,003 pregnant and 2361 postpartum women were extracted from the database. For unvaccinated postpartum women, intensive care unit (ICU) admission was more likely; invasive ventilation need was more probable if they tested positive for the original, Gamma, and Omicron variants; and chances of death were higher when infected with the original and Gamma variants than when infected with other variants. Vaccinated patients had reduced adverse outcome probability, including ICU admission, invasive ventilation requirement, and death. Postpartum women showed worse outcomes, particularly when unvaccinated, than pregnant women. Hence, vaccination of pregnant and postpartum women should be given top priority.