Miracle-dz/UniFAR-FTUs huggingface dataset:
A DISK-BASED DYNAMICAL MASS ESTIMATE FOR THE YOUNG BINARY V4046 Sgr

We present sensitive, arcsecond-resolution Submillimeter Array observations of the 12CO J = 2–1 line emission from the circumstellar disk orbiting the double-lined spectroscopic binary star V4046 Sgr. Based on a simple model of the disk structure, we use a novel Monte Carlo Markov Chain technique to extract the Keplerian velocity field of the disk from these data and estimate the total mass of the central binary. Assuming the distance inferred from kinematic parallax measurements in the literature (d ≈ 73 pc), we determine a total stellar mass M* = 1.75+0.09− 0.06 M☉ and a disk inclination id = 33. °5+0.7− 1.4 from face-on. These measurements are in excellent agreement with independent dynamical constraints made from multi-epoch monitoring of the stellar radial velocities, confirming the absolute accuracy of this precise (∼few percent uncertainties) disk-based method for estimating stellar masses and reaffirming previous assertions that the disk and binary orbital planes are well aligned (with |id − i*| ≈ 0.°1 ± 1°). Using these results as a reference, we demonstrate that various pre-main-sequence evolution models make consistent and accurate predictions for the masses of the individual components of the binary, and uniformly imply an advanced age of ∼5–30 Myr. Taken together, these results verify that V4046 Sgr is one of the precious few nearby and relatively evolved pre-main-sequence systems that still hosts a gas-rich accretion disk.
Entropy of thin shells in a (2+1)-dimensional asymptotically AdS spacetime and the BTZ black hole limit

The thermodynamic equilibrium states of a static thin ring shell in a (2+1)-dimensional spacetime with a negative cosmological constant are analyzed. Inside the ring, the spacetime is pure anti-de Sitter (AdS), whereas outside it is a Ba\~nados-Teitelbom-Zanell$ (BTZ) spacetime and thus asymptotically AdS. The first law of thermodynamics applied to the thin shell, plus one equation of state for the shell's pressure and another for its temperature, leads to a shell's entropy, which is a function of its gravitational radius alone. A simple example for this gravitational entropy, namely, a power law in the gravitational radius, is given. The equations of thermodynamic stability are analyzed, resulting in certain allowed regions for the parameters entering the problem. When the Hawking temperature is set on the shell and the shell is pushed up to its own gravitational radius, there is a finite quantum backreaction that does not destroy the shell. One then finds that the entropy of the shell at the shell's gravitational radius is given by the Bekenstein-Hawking entropy.
UVIT–HST–GAIAview of NGC 288: a census of the hot stellar population and its properties from UV

A complete census of Blue Horizontal Branch (BHB) and Blue Straggler Star (BSS) population within the 10$'$ radius from the center of the Globular Cluster, NGC 288 is presented, based on the images from the Ultraviolet Imaging Telescope (UVIT). The UV and UV$-$optical Colour-Magnitude Diagrams (CMDs) are constructed by combining the UVIT, HST-ACS and ground data and compared with the BaSTI isochrones generated for UVIT filters. We used stellar proper motions data from GAIA DR2 to select the cluster members. Our estimations of the temperature distribution of 110 BHB stars reveal two peaks with the main peak at $T_{eff}\sim$ 10,300 K with the distribution extending up to $T_{eff}\sim$ 18,000 K. We identify the well known photometric gaps including the G-jump in the BHB distribution which are located between the peaks. We detect a plateau in the FUV magnitude for stars hotter than $T_{eff}\sim$ 11,500 K (G-jump), which could be due to the effect of atomic diffusion. We detect 2 Extreme HB (EHB) candidates with temperatures ranging from 29,000 to 32,000 K. The radial distribution of 68 BSSs suggests that the bright BSSs are more centrally concentrated than the faint BSS and the BHB distribution. We find that the BSSs have a mass range of 0.86 - 1.25 M$_{\odot}$ and an age range of 2 - 10 Gyr with a peak at 1 M$_{\odot}$ and 4 Gyr respectively. This study showcases the importance of combining UVIT with HST, ground, and GAIA data in deriving HB and BSS properties.
Biased tracers and time evolution

We study the effect of time evolution on galaxy bias. We argue that at any order in perturbations, the galaxy density contrast can be expressed in terms of a finite set of locally measurable operators made of spatial and temporal derivatives of the Newtonian potential. This is checked in an explicit third order calculation. There is a systematic way to derive a basis for these operators. This basis spans a larger space than the expansion in gravitational and velocity potentials usually employed, although new operators only appear at fourth order. The basis is argued to be closed under renormalization. Most of the arguments also apply to the structure of the counter-terms in the effective theory of large-scale structure.
Do high energy astrophysical neutrinos trace star formation?

The IceCube Neutrino Observatory has provided the first map of the high energy (∼ 0.01–1 PeV) sky in neutrinos. Since neutrinos propagate undeflected, their arrival direction is an important identifier for sources of high energy particle acceleration. Reconstructed arrival directions are consistent with an extragalactic origin, with possibly a galactic component, of the neutrino flux. We present a statistical analysis of positional coincidences of the IceCube neutrinos with known astrophysical objects from several catalogs. When considering starburst galaxies with the highest flux in gamma-rays and infrared radiation, up to n=8 coincidences are found, representing an excess over the ∼4 predicted for the randomized, or ``null'' distribution. The probability that this excess is realized in the null case, the p-value, is p=0.042. This value falls to p=0.003 for a partial subset of gamma-ray-detected starburst galaxies and superbubble regions in the galactic neighborhood. Therefore, it is possible that starburst galaxies, and the typically hundreds of superbubble regions within them, might account for a portion of IceCube neutrinos. The physical plausibility of such correlation is discussed briefly.
Towards Energy-Preserving Natural Language Understanding With Spiking Neural Networks

Artificial neural networks have shown promising results in a variety of natural language understanding (NLU) tasks. Despite their successes, conventional neural-based NLU models are criticized for high energy consumption, making them laborious to be widely applied in low-power electronics, such as smartphones and intelligent terminals. In this paper, we introduce a potential direction to alleviate this bottleneck by proposing a spiking encoder. The core of our model is bi-directional spiking neural network (SNN) which transforms numeric values into discrete spiking signals and replaces massive multiplications with much cheaper additive operations. We examine our model on sentiment classification and machine translation tasks. Experimental results reveal that our model achieves comparable classification and translation accuracy to advanced Transformer baseline, whereas significantly reduces the required computational energy to 0.82%.
Lagrangian cascade in three-dimensional homogeneous and isotropic turbulence

Abstract In this work, the scaling statistics of the dissipation along Lagrangian trajectories are investigated by using fluid tracer particles obtained from a high-resolution direct numerical simulation with $\mathit{Re}_{\lambda }=400$. Both the energy dissipation rate $\epsilon $ and the local time-averaged $\epsilon _{\tau }$ agree rather well with the lognormal distribution hypothesis. Several statistics are then examined. It is found that the autocorrelation function $\rho (\tau )$ of $\ln (\epsilon (t))$ and variance $\sigma ^2(\tau )$ of $\ln (\epsilon _{\tau }(t))$ obey a log-law with scaling exponent $\beta '=\beta =0.30$ compatible with the intermittency parameter $\mu =0.30$. The $q{\rm th}$-order moment of $\epsilon _{\tau }$ has a clear power law on the inertial range $10<\tau /\tau _{\eta }<100$. The measured scaling exponent $K_L(q)$ agrees remarkably with $q-\zeta _L(2q)$ where $\zeta _L(2q)$ is the scaling exponent estimated using the Hilbert methodology. All of these results suggest that the dissipation along Lagrangian trajectories could be modelled by a multiplicative cascade.
Cyclic and ekpyrotic universes in modified Finsler osculating gravity on tangent Lorentz bundles

We consider models of an accelerating Universe elaborated for Finsler-like gravity theories constructed on tangent bundles to Lorentz manifolds. In the osculating approximation, certain locally anisotropic configurations are similar to those for f(R) gravity. This allows us to generalize a proposal by Nojiri et al (2011 AIP Conf. Proc. 1458 207–21) in order to reconstruct and compare two classes of Einstein–Finsler gravity (EFG) and f(R) gravity theories using modern cosmological data and realistic physical scenarios. We conclude that EFG provides inflation, acceleration and little rip evolution scenarios with realistic alternatives to standard ΛCDM cosmology. The approach is based on a proof that there is a general decoupling property of gravitational field equations in EFG and modified theories which allows us to generate off-diagonal cosmological solutions.
Polytropic dark haloes of elliptical galaxies

The kinematics of stars and planetary nebulae in early-type galaxies provide vital clues to the enigmatic physics of their dark matter haloes. We fit published data for 14 such galaxies using a spherical, self-gravitating model with two components: (i) a Sersic stellar profile fixed according to photometric parameters, and (ii) a polytropic dark matter halo that conforms consistently to the shared gravitational potential. The polytropic equation of state can describe extended theories of dark matter involving self-interaction, non-extensive thermostatistics or boson condensation (in a classical limit). In such models, the flat-cored mass profiles widely observed in disc galaxies are due to innate dark physics, regardless of any baryonic agitation. One of the natural parameters of this scenario is the number of effective thermal degrees of freedom of dark matter (Fd) which is proportional to the dark heat capacity. By default, we assume a cosmic ratio of baryonic and dark mass. Non-Sersic kinematic ideosyncrasies and possible non-sphericity thwart fitting in some cases. In all 14 galaxies, the fit with a polytropic dark halo improves or at least gives similar fits to the velocity dispersion profile, compared to a stars-only model. The good halo fits usually prefer Fd values from six to eight. This range complements the recently inferred limit of 7 < Fd < 10, derived from constraints on galaxy cluster core radii and black hole masses. However, a degeneracy remains: radial orbital anisotropy or a depleted dark mass fraction could shift our models' preference towards lower Fd; whereas a loss of baryons would favour higher Fd.
Phase changes in delay propagation networks

The analysis of the dynamics of delays propagation is one of the major topics inside Air Transport Management research. Delays are generated by the elements of the system, but their propagation is a global process fostered by relationships inside the network. If the topology of such propagation process has been extensively studied in the literature, little attention has been devoted to the fact that such topology may have a dynamical nature. Here we differentiate between two phases of the system by applying two causality metrics, respectively describing the standard phase (i.e. propagation of normal delays) and a disrupted one (corresponding to abnormal and unexpected delays). We identify the critical point triggering the change of the topology of the system, in terms of delays magnitude, using a historical data set of flights crossing Europe in 2011. We anticipate that the proposed results will open new doors towards the understanding of the delay propagation dynamics and the mitigation of extreme events.
Fluctuation-induced quantum interactions between compact objects and a plane mirror

The interaction of compact objects with an infinitely extended mirror plane due to quantum fluctuations of a scalar or electromagnetic field that scatters off the objects is studied. The mirror plane is assumed to obey either Dirichlet or Neumann boundary conditions or to be perfectly reflecting. Using the method of images, we generalize a recently developed approach for compact objects in unbounded space to show that the Casimir interaction between the objects and the mirror plane can be accurately obtained over a wide range of separations in terms of charge and current fluctuations of the objects and their images. Our general result for the interaction depends only on the scattering matrices of the compact objects. It applies to scalar fields with arbitrary boundary conditions and to the electromagnetic field coupled to dielectric objects. For the experimentally important electromagnetic Casimir interaction between a perfectly conducting sphere and a plane mirror we present the first results that apply at all separations. We obtain both an asymptotic large-distance expansion and the two lowest-order correction terms to the proximity force approximation. The asymptotic Casimir–Polder potential for an atom and a mirror is generalized to describe the interaction between a dielectric sphere and a mirror, involving higher-order multipole polarizabilities that are important at sub-asymptotic distances.
Self-coherent phase reference sharing for continuous-variable quantum key distribution

Generating "locally" the local oscillator is a fundamental requirement for continous-variable quantum key distribution (CV-QKD), both for performance and security reasons. As a consequence, next-generation CV- QKD systems will have to be implemented with a local local oscillator (LLO). This issue has been explicitly tackled in recent works, where the proposed and implemented approach, that we call LLO-sequential, consists in sequentially (temporally) multiplexing quantum signal optical pulses with phase reference pilot tones optical pulses. We develop a comprehensive analysis of the noise model and the hardware requirements in order to perform LLO CV-QKD. This analysis allows to quantitatively understand one of the limits of CV-QKD implemented with the LLO-sequential approach: such systems, unless operated at very high speed, have very strong requirements in terms of tolerable laser phase noise. LLO-sequential CV-QKD can thus in practice only be implemented with expensive, low phase noise lasers, such as ECL lasers. The main contribution of this work is to introduce designs for LLO CV-QKD based on self-coherence phase sharing, in which the phase reference information and the quantum information are coherently obtained from a single optical wavefront. We propose in particular a design, called LLO-displacement, where the phase reference information is encoded in the displacement of the standard CV-QKD Gaussian modulated coherent state (GMCS) protocol. We analyze the performance and the hardware requirements of the LLO-displacement design and our results indicate that it can be used to perform CV-QKD over distances up to 100 km with realistic and affordable hardware, in particular with standard telecom equipment and low cost DFB lasers. This opens a practical path towards the development of coherent quantum communications systems compatible with next-generation networks requirements.
Latitudinal libration driven flows in triaxial ellipsoids

Motivated by understanding the liquid core dynamics of tidally deformed planets and moons, we present a study of incompressible flow driven by latitudinal libration within rigid triaxial ellipsoids. We first derive a laminar solution for the inviscid equations of motion under the assumption of uniform vorticity flow. This solution exhibits a resonance if the libration frequency matches the frequency of the spin-over inertial mode. Furthermore, we extend our model by introducing a reduced model of the effect of viscous Ekman layers in the limit of low Ekman number (Noir & Cébron, J. Fluid Mech., vol. 737, 2013, pp. 412–439). This theoretical approach is consistent with the results of Chan et al. (Phys. Earth Planet. Inter., vol. 187, 2011, pp. 404–415) and Zhang et al. (J. Fluid Mech., vol. 692, 2012, pp. 420–445) for spheroidal geometries. Our results are validated against systematic three-dimensional numerical simulations. In the second part of the paper, we present the first linear stability analysis of this uniform vorticity flow. To this end, we adopt different methods (Lifschitz & Hameiri, Phys. Fluids A, vol. 3, 1991, p. 2644; Gledzer & Ponomarev, Acad. Sci., USSR, Izv., Atmos. Ocean. Phys., vol. 13, 1977, pp. 565–569) that allow us to deduce upper and lower bounds for the growth rate of an instability. Our analysis shows that the uniform vorticity base flow is prone to inertial instabilities caused by a parametric resonance mechanism. This is confirmed by a set of direct numerical simulations. Applying our results to planetary settings, we find that neither a spin-over resonance nor an inertial instability can exist within the liquid core of the Moon, Io and Mercury.
Stellar statistics along the ecliptic and the impact on the K2 mission concept

Abstract K2 is the mission concept for a repurposed Kepler mission that uses two reaction wheels to maintain the satellite attitude and provide ~81 days of coverage for ten 105 deg2 fields along the ecliptic in the first 2.5 years of operation. We examine stellar populations based on the updated Besançon model of the Galaxy, comment on the general properties for the entire ecliptic plane, and provide stellar occurrence rates in the first six tentative K2 campaigns grouped by spectral type and luminosity class. For each campaign we distinguish between main the sequence stars and giants, and provide their density profile as a function of galactic latitude. We introduce the crowding metric that serves for optimized target selection across the campaigns. For all main sequence stars we compute the expected planetary occurrence rates for three planet sizes: 2–4, 4–8 and 8–32 R⊕ with orbital periods up to 50 days. In conjunction with Gaia and the upcoming Transiting Exoplanet Survey Satellite and Plato missions, K2 will become a gold mine for stellar and planetary astrophysics.
ON THE NEED FOR DEEP-MIXING IN ASYMPTOTIC GIANT BRANCH STARS OF LOW MASS

The photospheres of low-mass red giants show CNO isotopic abundances that are not satisfactorily accounted for by canonical stellar models. The same is true for the measurements of these isotopes and of the 26Al/27Al ratio in presolar grains of circumstellar origin. Non-convective mixing, occurring during both red giant branch (RGB) and asymptotic giant branch (AGB) stages, is the explanation commonly invoked to account for the above evidence. Recently, the need for such mixing phenomena on the AGB was questioned, and chemical anomalies usually attributed to them were suggested to be formed in earlier phases. We have therefore re-calculated extra-mixing effects in low-mass stars for both the RGB and AGB stages, in order to verify the above claims. Our results contradict them; we actually confirm that slow transport below the convective envelope occurs also on the AGB. This is required primarily by the oxygen isotopic mix and the 26Al content of presolar oxide grains. Other pieces of evidence exist, in particular from the isotopic ratios of carbon stars of type N, or C(N), in the Galaxy and in the LMC, as well as of SiC grains of AGB origin. We further show that, when extra-mixing occurs in the RGB phases of Population I stars above about 1.2 M☉, this consumes 3He in the envelope, probably preventing the occurrence of thermohaline diffusion on the AGB. Therefore, we argue that other extra-mixing mechanisms should be active in those final evolutionary phases.
Infrared and Visible Image Fusion via Decoupling Network

In general, the goal of the existing infrared and visible image fusion (IVIF) methods is to make the fused image contain both the high-contrast regions of the infrared image and the texture details of the visible image. However, this definition would lead the fusion image losing information from the visible image in high-contrast areas. For this problem, this article proposed a decoupling network-based IVIF method (DNFusion), which utilizes the decoupled maps to design additional constraints on the network to force the network to retain the saliency information of the source image effectively. The current definition of image fusion is satisfied while effectively maintaining the saliency objective of the source images. Specifically, the feature interaction module (FIM) inside effectively facilitates the information exchange within the encoder and improves the utilization of complementary information. Also, a hybrid loss function constructed with weight fidelity loss, gradient loss, and decoupling loss ensures the fusion image to be generated to effectively preserve the source image’s texture details and luminance information. The qualitative and quantitative comparison of extensive experiments demonstrates that our model can generate a fused image containing saliency objects and clear details of the source images, and the method we proposed has a better performance than other state-of-the-art (SOTA) methods.
Effect of Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) Laser Enamel Pre-Treatment on the Whitening Efficacy of a Bleaching Agent

Background: There are a number of different substances and treatments that are effective in mitigating the negative effects of tooth bleaching. It is essential, however, to consider whether or not the presence of these factors affects the efficiency of the bleaching agent. Aim: The purpose of this study is to determine how the pretreated enamel with a Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser affects the bleaching effect of hydrogen peroxide at a concentration of 35%. Methods and materials: Thirty samples were prepared from human-extracted permanent anterior teeth and stained using a tea solution. Based on the pre-treatment protocol, the samples were split into two equal groups (n = 15): In Group I, samples were submerged in saline solution for five minutes, while in Group II, Nd:YAG laser treatment was performed. Following pretreatment, samples from both groups were bleached with 35% hydrogen peroxide. Colour analysis of all samples was done before and after bleaching using a spectrophotometer. For the colour analysis, the CIE L*a*b* (Commission Internationale de l'Eclairage) System of colour measurement was used. For statistical analysis, Student t-tests (two-tailed, unpaired) were used to compare the means of two groups on a continuous scale. Results: Samples from both groups became lighter in colour following bleaching. After bleaching, there was no discernible difference in the total colour change between the two groups. Conclusion: The application of the Nd:YAG laser before bleaching did not influence the whitening efficacy of 35% hydrogen peroxide.