Miracle-dz/UniFAR-FTUs huggingface dataset:
Confinement of superconducting fluctuations due to emergent electronic inhomogeneities

The microscopic nature of an insulating state in the vicinity of a superconducting state in the presence of disorder is a hotly debated question. While the simplest scenario proposes that Coulomb interactions destroy the Cooper pairs at the transition, leading to localization of single electrons, an alternate possibility supported by experimental observations suggests that Cooper pairs instead directly localize. The question of the homogeneity, granularity, or possibly glassiness of the material on the verge of this transition is intimately related to this fundamental issue. Here, by combining macroscopic and nanoscale studies of superconducting ultrathin NbN films, we reveal nanoscopic inhomogeneities that emerge when the film thickness is reduced. For the thinnest films, scanning tunneling spectroscopy at low temperature unveils inhomogeneities in the superconducting properties, of typical size Li, that are not correlated to any structural inhomogeneity and that are found to persist above the critical temperature in the form of a pseudogap. Remarkably enough, while the thickest films display a purely two-dimensional behavior in the superconducting fluctuations above the critical temperature, paraconductivity in the pseudogap regime of the thinnest samples demonstrates fluctuations of the amplitude of the order parameter, corresponding to zero-dimensional fluctuating regions of size precisely Li. We propose that an anomalous diffusion slowing-down process is at play at long wave vectors, leading to some “confinement” of the superconducting fluctuations, which allows us to explain the simultaneous paradoxical presence of a pseudogap and zero-dimensional amplitude fluctuations of the order parameter. These findings call for further theoretical investigation to understand this intermediate state where Cooper pairs continuously evolve from a bound state of fermionic objects into localized bosonic entities.
Cold CO Gas in the Envelopes of FU Orionis-type Young Eruptive Stars

FU Orionis-type objects (FUors) are young stellar objects experiencing large optical outbursts due to highly enhanced accretion from the circumstellar disk onto the star. FUors are often surrounded by massive envelopes, which play a significant role in the outburst mechanism. Conversely, the subsequent eruptions might gradually clear up the obscuring envelope material and drive the protostar on its way to become a disk-only T Tauri star. Here we present an APEX 12CO and 13CO survey of eight southern and equatorial FUors. We measure the mass of the gaseous material surrounding our targets, locate the source of the CO emission, and derive physical parameters for the envelopes and outflows, where detected. Our results support the evolutionary scenario where FUors represent a transition phase from envelope-surrounded protostars to classical T Tauri stars.
Renormalization for free harmonic oscillators

We introduce a model of free harmonic oscillators that requires renormalization. The model is similar to but simpler than the soluble Lee model. We introduce two concrete examples: the first, resembling the three dimensional $\phi^4$ theory, needs only mass renormalization, and the second, resembling the four dimensional $\phi^4$ theory and the Lee model, needs additional renormalization of a coupling and a wave function.
Black hole starvation and bulge evolution in a Milky Way-like galaxy

We present a new zoom-in hydrodynamical simulation, `ErisBH', which features the same initial conditions, resolution, and sub-grid physics as the close Milky Way-analogue `Eris' (Guedes et al. 2011), but it also includes prescriptions for the formation, growth and feedback of supermassive black holes. This enables a detailed study of black hole evolution and the impact of active galactic nuclei (AGN) feedback in a late-type galaxy. At z = 0, the main galaxy of ErisBH hosts a central black hole of 2.6 × 106 M⊙, which correlates to the bulge mass and the galaxy's central velocity dispersion similarly to what is observed in the Milky Way and in pseudobulges. During its evolution, the black hole grows mostly through mergers with black holes brought in by accreted satellite galaxies and very little by gas accretion (due to the modest amount of gas that reaches the central regions). AGN feedback is weak and it affects only the central 1-2 kpc. Yet, it limits the growth of the bulge, which results in a rotation curve that, in the inner ˜ 10 kpc, is flatter than that of Eris. We find that ErisBH is more prone to instabilities than Eris, due to its smaller bulge and larger disc. At z ˜ 0.3, an initially small bar grows to be of a few disc scalelengths in size. The formation of the bar causes a small burst of star formation in the inner few hundred pc, provides new gas to the central black hole and causes the bulge to have a boxy/peanut morphology by z = 0.
RECURRENT NOVAE IN M31

The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova (RN) candidates. To pass the initial screen and qualify as a RN candidate, two or more eruptions were required to be coincident within 0. ′1, although this criterion was relaxed to 0. ′15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential RN systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent, the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as RNe, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be RNe, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with RNe. A Monte Carlo analysis shows that the discovery efficiency for RNe may be as low as 10% that for novae in general, suggesting that as many as one in three nova eruptions observed in M31 arise from progenitor systems having recurrence times ≲ ? > 100 yr. For plausible system parameters, it appears unlikely that RNe can provide a significant channel for the production of Type Ia supernovae.
Destroying Kerr-Sen black holes

By neglecting the self-force, self-energy, and radiative effects, it has been shown that an extremal or near-extremal Kerr-Newman black hole can turn into a naked singularity when it captures charged and spinning massive particles. A straightforward question then arises: do charged and rotating black holes in string theory possess the same property? In this paper we apply the Wald's gedanken experiment, in his study on the possibility of destroying extremal Kerr-Newman black holes, to the case of (near-)extremal Kerr-Sen black holes. We find that feeding a test particle into a (near-)extremal Kerr-Sen black hole could lead to a violation of the extremal bound for the black hole.
General relativistic simulations of compact binary mergers as engines for short gamma-ray bursts

Black hole—neutron star (BHNS) and neutron star—neutron star (NSNS) binaries are among the favored candidates for the progenitors of the black hole—disk systems that may be the engines powering short-hard gamma ray bursts. After almost two decades of simulations of binary NSNSs and BHNSs in full general relativity we are now beginning to understand the ingredients that may be necessary for these systems to launch incipient jets. Here, we review our current understanding, and summarize the surprises and lessons learned from state-of-the-art (magnetohydrodynamic) simulations in full general relativity of BHNS and NSNS mergers as jet engines for short-hard gamma-ray bursts. We also propose a new approach to probing the nuclear equation of state by virtue of multimessenger observations.
Sedative administration in Spanish hospitals in the context of perinatal loss: findings from a mixed-methods study

ABSTRACT This article explores the contexts, processes and motivations behind the administration of sedatives (minor tranquilisers) in the time around perinatal loss. Using a mixed methods design, an online survey of 796 women and 13 narrative interviews were conducted. The participants had experienced a stillbirth or termination of pregnancy from 16 weeks or a neonatal death in Spanish hospitals. The quantitative (univariate and CHAID decision-tree) and qualitative (narrative-linguistic) analysis found that sedative administration was pervasive across care contexts and appears to be naturalised despite contradicting practice recommendations. Sedative administration was associated with emotional control and avoidance of loss, lack of accompaniment and on occasion with managing disruptive patients. Lack of informed consent was very common, with little explanation of side-effects prior to administration. In the participants’ narratives, health professionals tended to construct sedatives as benign, but for some women the effects were counterproductive to loss and grief and related to persistent regrets about decisions. The study concludes that, in the context of perinatal loss, sedative administration was highly integrated into the fabric of medicalised care. As a socio-political and cultural practice underscored by gender-based care dynamics, there seems to be an imbalance between benefit and risk to women’s welfare.
Plasmalogens and platelet‐activating factor roles in chronic inflammatory diseases

Fatty acids and phospholipid molecules are essential for determining the structure and function of cell membranes, and they hence participate in many biological processes. Platelet activating factor (PAF) and its precursor plasmalogen, which represent two subclasses of ether phospholipids, have attracted increasing research attention recently due to their association with multiple chronic inflammatory, neurodegenerative, and metabolic disorders. These pathophysiological conditions commonly involve inflammatory processes linked to an excess presence of PAF and/or decreased levels of plasmalogens. However, the molecular mechanisms underlying the roles of plasmalogens in inflammation have remained largely elusive. While anti‐inflammatory responses most likely involve the plasmalogen signal pathway; pro‐inflammatory responses recruit arachidonic acid, a precursor of pro‐inflammatory lipid mediators which is released from membrane phospholipids, notably derived from the hydrolysis of plasmalogens. Plasmalogens per se are vital membrane phospholipids in humans. Changes in their homeostatic levels may alter cell membrane properties, thus affecting key signaling pathways that mediate inflammatory cascades and immune responses. The plasmalogen analogs of PAF are also potentially important, considering that anti‐PAF activity has strong anti‐inflammatory effects. Plasmalogen replacement therapy was further identified as a promising anti‐inflammatory strategy allowing for the relief of pathological hallmarks in patients affected by chronic diseases with an inflammatory component. The aim of this Short Review is to highlight the emerging roles and implications of plasmalogens in chronic inflammatory disorders, along with the promising outcomes of plasmalogen replacement therapy for the treatment of various PAF‐related chronic inflammatory pathologies.
Coplanar streams, pancakes and angular‐momentum exchange in high‐z disc galaxies

We study the feeding of massive galaxies at high redshift through streams from the cosmic web using the Mare Nostrum hydrocosmological simulation. Our statistical sample consists of 350 dark matter haloes of ≃1012 M⊙ at z= 2.5. We find that ∼70 per cent of the influx into the virial radius Rv is in narrow streams covering 10 per cent of the virial shell. On average 64 per cent of the stream influx is in one stream, and 95 per cent is in three dominant streams. The streams that feed a massive halo tend to lie in a plane that extends from half to a few Rv, hereafter ‘the stream plane’ (SP). The streams are typically embedded in a thin sheet of low-entropy gas, a Zel’dovich pancake, which carries ∼20 per cent of the influx into Rv. The filaments-in-a-plane configuration about the massive haloes at the nodes of the cosmic web differs from the large-scale structure of the web where the filaments mark the intersections of slanted sheets. The SP is only weakly aligned with the angular momentum (AM) near Rv, consistent with the fact that typically 80 per cent of the AM is carried by one dominant stream. The galactic disc plane shows a weak tendency to be perpendicular to the large-scale SP, consistent with tidal-torque theory. Most interesting, the direction of the disc AM is only weakly correlated with the AM direction at Rv. This indicates a significant AM exchange at the interphase between streams and disc in the greater environment of the disc inside an ‘AM sphere’ of radius ∼0.3Rv. The required large torques are expected based on the perturbed morphology and kinematics within this interaction sphere. This AM exchange may or may not require a major modification of the standard disc modelling based on AM conservation, depending on the extent to which the amplitude of the disc AM is affected, which is yet to be studied.
A POPULATION OF X-RAY WEAK QUASARS: PHL 1811 ANALOGS AT HIGH REDSHIFT

We report the results from Chandra and XMM-Newton observations of a sample of 10 type 1 quasars selected to have unusual UV emission-line properties (weak and blueshifted high-ionization lines; strong UV Fe emission) similar to those of PHL 1811, a confirmed intrinsically X-ray weak quasar. These quasars were identified by the Sloan Digital Sky Survey at high redshift (z ≈ 2.2); eight are radio quiet while two are radio intermediate. All of the radio-quiet PHL 1811 analogs, without exception, are notably X-ray weak by a mean factor of ≈13. These sources lack broad absorption lines and have blue UV/optical continua, supporting the hypothesis that they are intrinsically X-ray weak like PHL 1811 itself. However, their average X-ray spectrum appears to be harder than those of typical quasars, which may indicate the presence of heavy intrinsic X-ray absorption. Our sample of radio-quiet PHL 1811 analogs supports a connection between an X-ray weak spectral energy distribution and PHL 1811-like UV emission lines; this connection provides an economical way to identify X-ray weak type 1 quasars. The fraction of radio-quiet PHL 1811 analogs in the radio-quiet quasar population is estimated to be ≲ 1.2%. We have investigated correlations between relative X-ray brightness and UV emission-line properties (e.g., C iv equivalent width and blueshift) for a sample combining our radio-quiet PHL 1811 analogs, PHL 1811 itself, and typical type 1 quasars. These correlation analyses suggest that PHL 1811 analogs may have extreme wind-dominated broad emission-line regions. Observationally, the radio-quiet PHL 1811 analogs appear to be a subset (≈30%) of radio-quiet weak-line quasars (WLQs). The existence of a subset of quasars in which high-ionization “shielding gas” covers most of the broad emission-line region (BELR), but little more than the BELR, could potentially unify the PHL 1811 analogs and WLQs. The two radio-intermediate PHL 1811 analogs are X-ray bright. X-ray spectral analyses and consideration of their multiwavelength properties suggest that one of them has jet-dominated X-ray emission, while the nature of the other remains unclear.
Sleep apnea is associated with the increase of certain genera of Ruminococcaceae and Lachnospiraceae in the gut microbiome of hypertensive patients

ABSTRACT Background Obstructive sleep apnea (OSA) and hypertension are interrelated diseases linked to gut dysbiosis. This study aimed to investigate the effect of OSA on the gut microbiome in the context of hypertension and vice versa. Research design and methods Of 211 consecutively screened patients, 52 completed polysomnography study, medical history questionnaires, and fecal sample collection. 16S rRNA gene sequencing was performed on fecal samples, and diversity, richness, and microbial taxa were analyzed using bioinformatics. Results Alpha diversity showed slightly decreased diversity in OSA and hypertension groups without significant difference, and the hypoxia burden index (HBI) showed a weak positive correlation with Chao1 index (r = 0.342, p < 0.05) in OSA patients. Firmicutes-to-Bacteroidetes ratio was higher in patients with than without OSA. In hypertensive patients, those with OSA had higher Ruminococcus_1, Lachnoclostridium, Lachnospira, [Ruminococcus]_torques_group, and unidentified Lachnospiraceae levels than those without OSA. Conversely, in OSA patients, hypertensive patients had lower Faecalibacterium and Lachnospiraceae_NK4A136_group levels. Conclusion The present study suggests a possible compensatory mechanism for gut microbiome changes in sleep apnea pathophysiology. The positive correlation between HBI and alpha diversity, and increase in certain genera of Ruminococcaceae and Lachnospiraceae in OSA patients may represent an adaptive response to hypoxia.
Young open clusters in the galactic star forming region NGC 6357

NGC6357 is an active star forming region with very young massive open clusters (OC). These clusters contain some of the most massive stars in the Galaxy and strongly interact with nearby giant molecular clouds (GMC). We study the young stellar populations of the region and of the OC Pismis24, focusing on their relationship with the nearby GMCs. We seek evidence of triggered star formation propagating from the clusters. We used new deep JHKs photometry, along with unpublished deep IRAC/Spitzer MIR photometry, complemented with optical HST/WFPC2 high spatial resolution photometry and X-ray Chandra observations, to constrain age, initial mass function, and star formation modes in progress. We carefully examine and discuss all sources of bias (saturation, confusion, different sensitivities, extinction). NGC6357 hosts three large young stellar clusters, of which Pismis24 is the most prominent. We found that Pismis24 is a very young (~1-3 Myr) OC with a Salpeter-like IMF and a few thousand members. A comparison between optical and IR photometry indicates that the fraction of members with a NIR excess (i. e., with a circumstellar disk) is in the range 0.3-0.6, consistent with its photometrically derived age. We also find that Pismis24 is likely subdivided into a few different sub-clusters, one of which contains almost all the massive members. There are indications of current star formation triggered by these massive stars, but clear age trends could not be derived (although the fraction of stars with a NIR excess does increase towards the HII region associated with the cluster). The gas out of which Pismis24 formed must have been distributed in dense clumps within a cloud of less dense gas ~1 pc in radius. Our findings provide some new insight into how young stellar populations and massive stars emerge, and evolve in the first few Myr after birth, from a giant molecular cloud complex.
THE RADIO CONTINUUM, FAR-INFRARED EMISSION, AND DENSE MOLECULAR GAS IN GALAXIES

A tight linear correlation is established between the HCN line luminosity and the radio continuum (RC) luminosity for a sample of 65 galaxies (from Gao & Solomon's HCN survey), including normal spiral galaxies and luminous and ultraluminous infrared galaxies (LIRGs/ULIRGs). After analyzing the various correlations among the global far-infrared (FIR), RC, CO, and HCN luminosities and their various ratios, we conclude that the FIR–RC and FIR–HCN correlations appear to be linear and are the tightest among all correlations. The combination of these two correlations could result in the tight RC–HCN correlation we observed. Meanwhile, the nonlinear RC–CO correlation shows slightly larger scatter as compared with the RC–HCN correlation, and there is no correlation between ratios of either RC/HCN–CO/HCN or RC/FIR–CO/FIR. In comparison, a meaningful correlation is still observed between ratios of RC/CO–HCN/CO. Nevertheless, the correlation between RC/FIR and HCN/FIR also disappears, reflecting again the two tightest FIR–RC and FIR–HCN correlations as well as suggesting that FIR seems to be the bridge that connects HCN with RC. Interestingly, despite obvious HCN–RC and RC–CO correlations, multi-parameter fits hint that while both RC and HCN contribute significantly (with no contribution from CO) to FIR, yet RC is primarily determined from FIR with a very small contribution from CO and essentially no contribution from HCN. These analyses independently confirm previous conclusions that it is practical to use RC luminosity instead of FIR luminosity, at least globally, as an indicator of star formation rate in galaxies including LIRGs/ULIRGs, and HCN is a much better tracer of star-forming molecular gas and correlates with FIR much better than CO.
Polynomial automorphisms of C^n preserving the Markoff-Hurwitz polynomial

We study the action of the group of polynomial automorphisms of C^n (n>2) which preserve the Markoff-Hurwitz polynomial H(x):= x_1^2 + x_2^2 + . + x_n^2 - x_1 x_2 . x_n. Our main results include the determination of the group, the description of a non-empty open subset of C^n on which the group acts properly discontinuously (domain of discontinuity), and identities for the orbit of points in the domain of discontinuity.
Climate models fail to capture strengthening wintertime North Atlantic jet and impacts on Europe

Projections of wintertime surface climate over Europe depend on reliable simulations of the North Atlantic atmospheric circulation from climate models. However, it is unclear whether these models capture the long-term observed trends in the North Atlantic circulation. Here, we show that over the period from 1951 to 2020, the wintertime North Atlantic jet has strengthened, while model trends are, on average, only very weakly positive. The observed strengthening is greater than in any one of the 303 simulations from 44 climate models considered in our study. This divergence between models and observations is now much more apparent because of a very strong jet observed over the past decade. The models similarly have difficulty capturing the observed precipitation trends over Europe. Our results suggest that projections of winter atmospheric circulation and associated precipitation over Europe may be unreliable because they fail to capture the response to human emissions or underestimate the magnitude of multidecadal-to-centennial time scale internal variability.
Effect of finite temperature and uniaxial anisotropy on the Casimir effect with three-dimensional topological insulators

In this work we study the Casimir effect with three-dimensional topological insulators including the effects of temperature and uniaxial anisotropy. We find that the reported repulsive behavior and the equilibrium point are robust features of the system, and are favored by low temperatures and the enhancement of the optical response parallel to the optical axis. The dependence of the equilibrium point with temperature and with the topological magnetoelectric polarizability characteristic of three-dimensional topological insulators is also discussed. PACS numbers:
Stimulated Supersymmetry Breaking

We show that small soft terms can create a supersymmetry breaking minimum along a pseudoflat direction of a hidden sector which would otherwise be incapable of spontaneous supersymmetry breaking. As this minimum lies along a pseudoflat direction, with nonzero F- or D-terms, the resultant supersymmetry breaking in the hidden sector can be orders of magnitude greater than the soft terms which created the minimum. This opens new avenues for building models of gauge mediation, may have consequences for the cosmology of hidden sectors, and strengthens the case for multiple supersymmetry breaking sectors.