Miracle-dz/UniFAR-FTUs huggingface dataset:
A SEARCH FOR NONTOROIDAL TOPOLOGICAL LENSING IN THE SLOAN DIGITAL SKY SURVEY QUASAR CATALOG

Flat space models with multiply connected topology, which have compact dimensions, are tested against the distribution of high-redshift (z ⩾ 4) quasars of the Sloan Digital Sky Survey (SDSS). When the compact dimensions are smaller in size than the observed universe, topological lensing occurs, in which multiple images of single objects (ghost images) are observed. We improve on the recently introduced method to identify ghost images by means of four-point statistics. Our method is valid for any of the 17 multiply connected flat models, including nontoroidal ones that are compacted by screw motions or glide reflection. Applying the method to the data revealed one possible case of topological lensing caused by sixth-turn screw motion, however, it is consistent with the simply connected model by this test alone. Moreover, simulations suggest that we cannot exclude the other space models despite the absence of their signatures. This uncertainty mainly originates from the patchy coverage of SDSS in the south Galactic cap, and this situation will be improved by future wide-field spectroscopic surveys.
The negatively charged nitrogen-vacancy centre in diamond: the electronic solution

The negatively charged nitrogen-vacancy centre is a unique defect in diamond that possesses properties highly suited to many applications, including quantum information processing, quantum metrology and biolabelling. Although the unique properties of the centre have been extensively documented and utilized, a detailed understanding of the physics of the centre has not yet been achieved. Indeed, there persist a number of points of contention regarding the electronic structure of the centre, such as the ordering of the dark intermediate singlet states. Without a detailed model of the centre's electronic structure, the understanding of the system's unique dynamical properties cannot effectively progress. In this work, the molecular model of the defect centre is fully developed to provide a self-consistent model of the complete electronic structure of the centre. The application of the model to describe the effects of electric, magnetic and strain interactions, as well as the variation of the centre's fine structure with temperature, provides an invaluable tool to those studying the centre and a means of designing future empirical and ab initio studies of this important defect.
EVIDENCE FOR THE WHITE DWARF NATURE OF MIRA B

The nature of the accreting companion to Mira—the prototypical pulsating asymptotic giant branch star—has been a matter of debate for more than 25 years. Here, we use a quantitative analysis of the rapid optical brightness variations from this companion, Mira B, which we observed with the Nickel Telescope at Lick Observatory, to show that it is a white dwarf (WD). The amplitude of aperiodic optical variations on timescales of minutes to tens of minutes (≈0.2 mag) is consistent with that of accreting WDs in cataclysmic variables on these same timescales. It is significantly greater than that expected from an accreting main-sequence star. With Mira B identified as a WD, its ultraviolet (UV) and optical luminosities, along with constraints on the WD effective temperature from the UV, indicate that it accretes at ∼10−10 M☉ yr-1. This accretion rate is lower than that predicted by Bondi–Hoyle theory. The accretion rate is high enough, however, to explain the weak X-ray emission, since the accretion-disk boundary layer around a low-mass WD accreting at this rate is likely to be optically thick and therefore to emit primarily in the far or extreme UV. Furthermore, the finding that Mira B is a WD means that it has experienced, and will continue to experience, nova explosions, roughly every 106 years. It also highlights the similarity between Mira AB and other jet-producing symbiotic binaries such as R Aquarii, CH Cygni, and MWC 560, and therefore raises the possibility that Mira B launched the recently discovered bipolar streams from this system.
Fermion interactions and universal behavior in strongly interacting theories

The theory of the strong interaction, quantum chromodynamics (QCD), describes the generation of hadronic masses and the state of hadronic matter during the early stages of the evolution of the universe. As a complement, experiments with ultracold fermionic atoms provide a clean environment to benchmark our understanding of dynamical formation of condensates and the generation of bound states in strongly interacting many-body systems. Renormalization Group (RG) techniques offer great potential for theoretical advances in both hot and dense QCD and many-body physics, but their connections have not yet been investigated in great detail. We aim to take a further step to bridge this gap. A cross-fertilization is indeed promising since it may eventually provide us with an ab initio description of hadronization, condensation and bound-state formation in strongly interacting theories. After giving a thorough introduction to the derivation and analysis of fermionic RG flows, we give an introductory review of our present understanding of universal long-range behavior in various different theories, ranging from non-relativistic many-body problems to relativistic gauge theories, with an emphasis on scaling behavior of physical observables close to quantum phase transitions (i.e. phase transitions at zero temperature) as well as thermal phase transitions.
Branes and wrapping rules

We show that the branes of ten-dimensional IIA/IIB string theory must satisfy, upon toroidal compactification, specific wrapping rules in order to reproduce the number of supersymmetric branes that follows from a supergravity analysis. The realization of these wrapping rules suggests that IIA/IIB string theory contains a whole class of so-called non-standard Kaluza-Klein monopoles. Whereas branes couple to p-form potentials these non-standard Kaluza-Klein monopoles can be associated with mixed-symmetry potentials. We discuss a possible E11-symmetry underlying these new structures.
Atmospheric tides and their consequences on the rotational dynamics of terrestrial planets

Atmospheric tides can have a strong impact on the rotational dynamics of planets. They are of most importance for terrestrial planets located in the habitable zone of their host star, where their competition with solid tides is likely to drive the body towards non-synchronized rotation states of equilibrium, as observed in the case of Venus. Contrary to other planetary layers, the atmosphere is sensitive to both gravitational and thermal forcings, through a complex dynamical coupling involving the effects of Coriolis acceleration and characteristics of the atmospheric structure. These key physics are usually not taken into account in modelings used to compute the evolution of planetary systems, where tides are described with parametrised prescriptions. In this work, we present a new ab initio modeling of atmospheric tides adapting the theory of the Earth’s atmospheric tides (Chapman & Lindzen 1970) to other terrestrial planets. We derive analytic expressions of the tidal torque, as a function of the tidal frequency and parameters characterizing the internal structure (e.g. the Brunt-Väisälä frequency, the radiative frequency, the pressure heigh scale). We show that stratification plays a key role, the tidal torque being strong in the case of convective atmospheres (i.e. with a neutral stratification) and weak in case of atmosphere convectively stable. In a second step, the model is used to determine the non-synchronized rotation states of equilibrium of Venus-like planets as functions of the physical parameters of the system. These results are detailed in Auclair-Desrotour et al. (2016a) and Auclair-Desrotour et al. (2016b).
Searching for Evidence of Energetic Feedback in Distant Galaxies: A Galaxy Wide Outflow in a z~2 Ultraluminous Infrared Galaxy

Leading models of galaxy formation require large-scale energetic outflows to regulate the growth of distant galaxies and their central black holes. However, current observational support for this hypothesis at high redshift is mostly limited to rare z>2 radio galaxies. Here we present Gemini-North NIFS Intregral Field Unit (IFU) observations of the [OIII] emission from a z~2 ultraluminous infrared galaxy (L_IR>10^12 solar luminosities) with an optically identified Active Galactic Nucleus (AGN). The spatial extent (~4-8 kpc) of the high velocity and broad [OIII] emission are consistent with that found in z>2 radio galaxies, indicating the presence of a large-scale energetic outflow in a galaxy population potentially orders of magnitude more common than distant radio galaxies. The low radio luminosity of this system indicates that radio-bright jets are unlikely to be responsible for driving the outflow. However, the estimated energy input required to produce the large-scale outflow signatures (of order ~10^59 ergs over ~30 Myrs) could be delivered by a wind radiatively driven by the AGN and/or supernovae winds from intense star formation. The energy injection required to drive the outflow is comparable to the estimated binding energy of the galaxy spheroid, suggesting that it can have a significant impact on the evolution of the galaxy. We argue that the outflow observed in this system is likely to be comparatively typical of the high-redshift ULIRG population and discuss the implications of these observations for galaxy formation models.
Gender gap and polarisation of physics on global courses

We extend on previous research on the Force Concept Inventory (FCI) given to first year classical mechanics students (N = 66 students, over four years) pre and post score, for students on an international (global) course at Osaka University. In particular, we revisit the notion of “polarisation” in connection with the six polarisation-inducing questions in the FCI and examine its gender aspect. Our data suggest that this phenomenon is not unique to one gender. Furthermore, the extent by which it is exhibited by males may differ from that of females at the beginning (pretest) but the gap closes upon learning more about forces (posttest). These findings are for the most part, complemented by our result for the FCI as a whole. Although the differences in means for males and females suggest a gender gap, statistical analysis shows that there is no gender difference at the 95% confidence level.
Geometry and stability of spinning branes in AdS gravity

The geometry of spinning codimension-two branes in AdS spacetime is analyzed in three and higher dimensions. The construction of non-extremal solutions is based on identications in the covering of AdS space by isometries that have xed points. The discussion focuses on the cases where the parameters of spinning states can be related to the velocity of a boosted static codimension-two brane. The resulting conguration describes a single spinning brane, or a set of intersecting branes, each one produced by an independent identication. The nature of the singularity is also examined, establishing that the AdS curvature acquires one in the form of a Dirac delta distribution. The stability of the branes is studied in the framework of Chern-Simons AdS supergravity. A class of branes, characterized by one free parameter, are shown to be stable when the BPS conditions are satised. In 3D, these stable branes are extremal, while in higher dimensions, the BPS branes are not the extremal ones.
CFHTLenS: Improving the quality of photometric redshifts with precision photometry

Here we present the results of various approaches to measure accurate colours and photometric redshifts (photo-z’s) from wide-field imaging data. We use data from the Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS) which have been re- processed by the CFHT Lensing Survey (CFHTLenS) team in order to carry out a number of weak gravitational lensing studies. An emphasis is put on the correction of systematic effects in the photo-z’s arising from the different Point Spread Functions (PSF) in the five optical bands. Different ways of correcting these effects are discussed and the resulting photo-z accuracies are quantified by comparing the photo-z’s to large spectroscopic redshift (spec-z) data sets. Careful homogenisation of the PSF between bands leads to increased overall accuracy of photo-z’s. The gain is particularly pronounced at fainter magnitudes where galaxies are smaller and flux measurements are affected more by PSF-effects. We also study possible re- calibrations of the photometric zeropoints (ZPs) with the help of galaxies with known spec-z’s. We find that if PSF-effects are properly taken into account, a re-calibration of the ZPs becomes much less important suggesting that previous such re-calibrations described in the literature could in fact be mostly corrections for PSF-effects rather than corrections for real inaccuracies in the ZPs. The implications of this finding for future surveys like KiDS, DES, LSST, or Euclid are mixed. On the one hand, ZP re-calibrations with spec-z’s might not be as accurate as previously thought. On the other hand, careful PSF homogenisation might provide a way out and yield accurate, homogeneous photometry without the need for full spectroscopic coverage. This is the first paper in a series describing the technical aspects of CFHTLenS. (abridged)
Can Sports Practice in Childhood and Adolescence Be Associated with Higher Intensities of Physical Activity in Adult Life? A Retrospective Study in Community-Dwelling Adults

Introduction: Investigating the determinants of physical activity (PA) is an important strategy for the promotion of healthy lifestyles, mainly with PA of a moderate-to-vigorous intensity, which provides several health benefits in adulthood. In this sense, it is not clear whether early sports practice (ESP) during childhood and adolescence could be associated with the habitual practice of PA of higher intensities in adulthood. Objective: This study aimed to analyze the association of ESP in childhood and adolescence with different intensities of habitual PA in adulthood. Methods: A sample of 264 community-dwelling adults were randomly selected (42.2 ± 17.0 years, 57.5% of women). ESP during childhood and adolescence was evaluated using retrospective questions. Weekly minutes of PA were assessed using accelerometry and classified according to intensity as light, moderate, moderate-to-vigorous, vigorous and very vigorous. The association of ESP with a high level of PA (above median) in each intensity was analyzed using binary regression models. Results: The prevalence of ESP was 42.8% in childhood and 49.2% in adolescence. ESP in childhood was associated with a high level of very vigorous (OR: 2.48, p < 0.001) and vigorous PA (OR: 2.91, p < 0.001) in adulthood, but lost significance after adjustments by sex and age. ESP in adolescence was associated with a high level of very vigorous PA (OR: 1.99, p = 0.013) in the crude model and vigorous PA (OR: 2.21, p = 0.006), even after adjustments by age, sex and socioeconomic status. Conclusions: Engagement in sports practice during adolescence was associated with high levels of vigorous PA in adulthood and is an important period for healthy lifestyle promotion.
Coordination‐behavior patterns of control crews in digital nuclear power plants during emergencies from a network perspective: An exploratory study

This study aims to investigate the coordination‐behavior patterns of control crews in digital nuclear power plants (NPPs) during emergencies from a network perspective. We observed and coded 12 coordination processes (each from one crew) of handling simulated emergencies on a full‐scope dynamic simulator in Tianwan NPP of China. By calculating the proportion of coordination breakdowns and referring to the subjective evaluation of instructors, these control crews (all male) were classified into two performance levels (high and low). To compare the coordination‐behavior patterns between high‐ and low‐performing crews, we conducted social network analysis based on the number and direction of coordination behaviors. By examining intracrew relations in team coordination, this study indicated that high‐performing crews exhibited higher cohesion and more balanced behavioral patterns in team coordination than low‐performing ones. By investigating coordination‐behavior patterns from the hierarchical structure of relations in the team, this study revealed that high‐performing crews exhibited higher degree of team autonomy and self‐management among junior operators, as well as reactor operator (RO)‐centered pattern, whereas the low‐performing crews exhibited senior reactor operator‐centered pattern. For researchers, the results advance the understanding of the team coordination mechanism in NPP control rooms during emergencies and enrich team coordination theory in process control industries from the network perspective. In practice, this study suggested that the team coordination training of NPP control crews might be centered around junior operators (especially RO), with focuses on facilitating information sharing and mutual assistance between junior operators and enhancing the awareness of active cooperation of crew members. The results of the study provide nuclear instructors with practical reference to team coordination training and processes optimization.
Dark matter and dark energy from a Bose–Einstein condensate

We show that dark matter consisting of bosons of mass of about 1 eV or less has a critical temperature exceeding the temperature of the Universe at all times, and hence would have formed a Bose–Einstein condensate at very early epochs. We also show that the wavefunction of this condensate, via the quantum potential it produces, gives rise to a cosmological constant that may account for the correct dark energy content of our Universe. We argue that massive gravitons or axions are viable candidates for these constituents. In the far future this condensate is all that remains of our Universe.
A STOCHASTIC MODEL FOR THE LUMINOSITY FLUCTUATIONS OF ACCRETING BLACK HOLES

In this work, we have developed a new stochastic model for the fluctuations in light curves of accreting black holes. The model is based on a linear combination of stochastic processes and is also the solution to the linear diffusion equation perturbed by a spatially correlated noise field. This allows flexible modeling of the power spectral density (PSD), and we derive the likelihood function for the process, enabling one to estimate the parameters of the process, including break frequencies in the PSD. Our statistical technique is computationally efficient, unbiased by aliasing and red noise leak, and fully accounts for irregular sampling and measurement errors. We show that our stochastic model provides a good approximation to the X-ray light curves of galactic black holes, and the optical and X-ray light curves of active galactic nuclei (AGNs). We use the estimated timescales of our stochastic model to recover the correlation between characteristic timescale of the high-frequency X-ray fluctuations and black hole mass for AGNs, including two new “detections” of the timescale for Fairall 9 and NGC 5548. We find a tight anti-correlation between the black hole mass and the amplitude of the driving noise field, which is proportional to the amplitude of the high-frequency X-ray PSD, and we estimate that this parameter gives black hole mass estimates to within ∼0.2 dex precision, potentially the most accurate method for AGNs yet. We also find evidence that ≈13% of AGN optical PSDs fall off flatter than 1/f2 and, similar to previous work, find that the optical fluctuations are more suppressed on short timescales compared to the X-rays, but are larger on long timescales, suggesting that the optical fluctuations are not solely due to reprocessing of X-rays.
GAMMA-RAY POLARIZATION INDUCED BY COLD ELECTRONS VIA COMPTON PROCESSES

The polarization measurement is an important tool to probe the prompt emission mechanism in gamma-ray bursts (GRBs). The synchrotron photons can be scattered by cold electrons in the outflow via Compton scattering (CS) processes. The observed polarization depends on both the photon energy and the viewing angle. With the typical bulk Lorentz factor Γ ∼ 200, photons with energy E > 10 MeV tend to have smaller polarization than photons with energy E < 1 MeV. At the right viewing angle, i.e., θ ∼ Γ−1, the polarization achieves its maximal value, and the polarization angle changes 90° relative to the initial polarization direction. Thus, the synchrotron radiation plus CS model can naturally explain the 90° change of the polarization angle in GRB 100826A.
Information-theoretical analysis of topological entanglement entropy and multipartite correlations

A special feature of the ground state in a topologically ordered phase is the existence of large scale correlations depending only on the topology of the regions. These correlations can be detected by the topological entanglement entropy or by a measure called irreducible correlation. We show that these two measures coincide for states obeying an area law and having zero-correlation length. Moreover, we provide an operational meaning for these measures by proving its equivalence to the optimal rate of a particular class of secret sharing protocols. This establishes an information-theoretical approach to multipartite correlations in topologically ordered systems.
Driven multifluid magnetohydrodynamic molecular cloud turbulence

It is believed that turbulence may have a significant impact on star formation and the dynamics and evolution of the molecular clouds in which this occurs. It is also known that non-ideal magnetohydrodynamic (MHD) effects influence the nature of this turbulence. We present the results of a numerical study of four-fluid MHD turbulence in which the dynamics of electrons, ions, charged dust grains and neutrals and their interactions are followed. The parameters describing the fluid being simulated are based directly on observations of molecular clouds. We find that the velocity and magnetic field power spectra are strongly influenced by multifluid effects on length-scales at least as large as 0.05 pc. The probability density functions of the various species in the system are all found to be close to log-normal, with charged species having a slightly less platykurtic (flattened) distribution than the neutrals. We find that the introduction of multifluid effects does not significantly alter the structure functions of the centroid velocity increment.
Uncovering the hidden order in URu2Si2: Identification of Fermi surface instability and gapping

Spontaneous, collective ordering of electronic degrees of freedom leads to second-order phase transitions that are characterized by an order parameter. The notion "hidden order" (HO) has recently been used for a variety of materials where a clear phase transition occurs to a phase without a known order parameter. The prototype example is the heavy-fermion compound URu2Si2 where a mysterious HO transition occurs at 17.5K. For more than twenty years this system has been studied theoretically and experimentally without a firm grasp of the underlying physics. Using state-of-the-art density-functional theory calculations, we provide here a microscopic explanation for the HO. We identify the Fermi surface "hot spots" where degeneracy induces a Fermi surface instability and quantify how symmetry breaking lifts the degeneracy, causing a surprisingly large Fermi surface gapping. As mechanism for the HO we propose spontaneous symmetry breaking through collective antiferromagnetic moment excitations.
Large gaps between primes

We show that there exists pairs of consecutive primes less than $x$ whose difference is larger than $t(1+o(1))(\log{x})(\log\log{x})(\log\log\log\log{x})(\log\log\log{x})^{-2}$ for any fixed $t$. Our proof works by incorporating recent progress in sieve methods related to small gaps between primes into the Erdos-Rankin construction. This answers a well-known question of Erdos.