Miracle-dz/UniFAR-FTUs huggingface dataset:
The curve of compactified 6D gauge theories and integrable systems

We analyze the Seiberg-Witten curve of the six-dimensional = (1,1) gauge theory compactified on a torus to four dimensions. The effective theory in four dimensions is a deformation of the = 2* theory. The curve is naturally holomorphically embedding in a slanted four-torus — actually an abelian surface — a set-up that is natural in Witten's M-theory construction of = 2 theories. We then show that the curve can be interpreted as the spectral curve of an integrable system which generalizes the N-body elliptic Calogero-Moser and Ruijsenaars-Schneider systems in that both the positions and momenta take values in compact spaces. It turns out that the resulting system is not simply doubly elliptic, rather the positions and momenta, as two-vectors, take values in the ambient abelian surface. We analyze the two-body system in some detail. The system we uncover provides a concrete realization of a Beauville-Mukai system based on an abelian surface rather than a K3 surface.
OH AND H2O MASERS IN 74 STAR-FORMING REGIONS : THE FC89 DATABASE

Positions and spectra of 1665 MHz OH and 23 235 MHz H2 O masers in 74 star-forming regions are presented. This supplement provides an electronic version of the complete VLA database of interstellar masers observed by Forster & Caswell (1989). The fields observed comprise the majority of known interstellar OH and H2 O maser associations at galactic longitudes observable from both hemispheres. The database will be useful for interpreting continuum and molecular line observations of these regions, for investigations of the relationship between the masers and their local environment, and for temporal and kinematical studies of the masers themselves.
Discovery of Dying Active Galactic Nucleus in Arp 187: Experience of Drastic Luminosity Decline within 104 yr

Arp 187 is one of the fading active galactic nuclei (AGNs), whose AGN activity is currently decreasing in luminosity. We investigate the observational signatures of AGN in Arp 187, which trace various physical scales from less than 0.1 pc to the nearly 10 kpc, to estimate the long-term luminosity change over 104 yr. The Very Large Array 5 GHz and 8 GHz images and the ALMA 133 GHz images reveal bimodal jet lobes with ∼5 kpc size and the absence of the central radio core. The 6dF optical spectrum shows that Arp 187 hosts a narrow line region with the estimated size of ∼1 kpc, and the line strengths give the AGN luminosity of Lbol = 1.5 × 1046 erg s−1. On the other hand, the current AGN activity estimated from the AGN torus emission gives the upper bound of Lbol < 2.2 × 1043 erg s−1. The absence of the radio core gives the more strict upper bound of the current AGN luminosity of Lbol < 8.0 × 1040 erg s−1, suggesting that the central engine is already quenched. These multiwavelength signatures indicate that Arp 187 hosts a “dying” AGN: the central engine is already dead, but the large-scale AGN indicators are still observable as the remnant of the past AGN activity. The central engine has experienced the drastic luminosity decline by a factor of ∼103–5 fainter within ∼104 yr, which is roughly consistent with the viscous timescale of the inner part of the accretion disk within ∼500 yr.
Exploring the statistics of magnetic reconnection X-points in kinetic particle-in-cell turbulence

Magnetic reconnection is a ubiquitous phenomenon in turbulent plasmas. It is an important part of the turbulent dynamics and heating of space and astrophysical plasmas. We examine the statistics of magnetic reconnection using a quantitative local analysis of the magnetic vector potential, previously used in magnetohydrodynamics simulations, and now employed to fully kinetic particle-in-cell (PIC) simulations. Different ways of reducing the particle noise for analysis purposes, including multiple smoothing techniques, are explored. We find that a Fourier filter applied at the Debye scale is an optimal choice for analyzing PIC data. Finally, we find a broader distribution of normalized reconnection rates compared to the MHD limit with rates as large as 0.5 but with an average of approximately 0.1.
Wavy vortices in the flow between two long eccentric rotating cylinders I. Linear theory

This analysis deals with the occurrence of Coles’ wavy vortices in the flow between two eccentric cylinders when no Taylor vortex flow is present, and where the eccentricity is small and the clearance ratio is very small. This mathematical investigation can be seen as an extension of the previous papers of Di Prima (1963), Roberts (1965), Davey, Di Prima & Stuart (1968) on the concentric problem and the paper of Di Prima & Stuart (19726) which includes eccentricity. An extension to the latter paper is made by the inclusion of the time variable r in the equation for the amplitude B((/),t) of the Taylor vortices, (j) being the azimuthal variable. The results are compared with the observed critical speeds of Vohr (1967) for development of wave instability on Taylor vortices, and are qualitatively similar; they differ in magnitude from experiment, however, probably due to the absence of nonlinear effects.
Development of Lane Marking Detection and Classification for Perception System in Autonomous Vehicles

Lane marking detection is a necessary system in autonomous vehicles as well as a challenging one to develop. It forms the basis for intelligent systems in autonomous vehicle driving and has always been a concern in the field of computer vision, especially in perception systems. In fact, there are a lot of machine learning methods used for lane marking detection including CNN-based lane marking detection with various models and datasets for model training. In this research, a lane marking detection method based on instance segmentation is presented. The proposed method is trained using the TUSimple dataset. The lane marking detection results are then classified into 2 types of classes i.e., solid and dashed lines based on training using deep learning with the same dataset. Furthermore, the proposed lane marking detection and classification method is conducted in real experiments in urban area at Bandung, Indonesia. The method gives a promising result as it can well-classified the lanes with more than 70% accuracy.
A hybrid inversion scheme of Markov-chain Monte Carlo and iterative methods for diffuse optical tomography

Diffuse optical tomography is formulated as inverse coefficient problems for the diffusion equation. Iterative inversion schemes such as the Levenberg-Marquardt algorithm are known to fail when initial guesses are not close to the true value of the coefficient to be reconstructed. In this paper, we investigate how this weakness of iterative schemes is overcome by the use of Monte Carlo. We present a toy model of diffuse optical tomography for which the Levenberg-Marquardt algorithm fails to work but the Metropolis-Hastings Markov chain Monte Carlo works. We show that our proposed hybrid scheme solves the inverse problem efficiently by preparing a good initial guess by Monte Carlo and then computing the reconstructed value with the Levenberg-Marquardt algorithm starting from the found initial guess.
Accounting for Follow‐up Bias in Estimation of Human Immunodeficiency Virus Incidence Rates

The objective of this paper is to describe methods for estimating current incidence rates for human immunodeficiency virus (HIV) that account for follow‐up bias. Follow‐up bias arises when the incidence rate among individuals in a cohort who return for follow‐up is different from the incidence rate among those who do not return. The methods are based on the use of early markers of HIV infection such as p24 antigen. The first method, called the cross‐sectional method, uses only data collected at an initial base‐line visit. The method does not require follow‐up data but does require a priori knowledge of the mean duration of the marker (μ). A confidence interval procedure is developed that accounts for uncertainty in μ. The second method combines the base‐line data from all individuals together with follow‐up data from those individuals who return for follow‐up. This method has the distinct advantage of not requiring prior information about μ. Several confidence interval procedures for the incidence rate are compared by simulation. The methods are applied to a study in India to estimate current HIV incidence. These data suggest that the epidemic is growing rapidly in some subpopulations in India.
Percolation on an isotropically directed lattice

We investigate percolation on a randomly directed lattice, an intermediate between standard percolation and directed percolation, focusing on the isotropic case in which bonds on opposite directions occur with the same probability. We derive exact results for the percolation threshold on planar lattices, and present a conjecture for the value the percolation-threshold for in any lattice. We also identify presumably universal critical exponents, including a fractal dimension, associated with the strongly-connected components both for planar and cubic lattices. These critical exponents are different from those associated either with standard percolation or with directed percolation.
The low noise phase of a 2d active nematic

We consider a collection of self-driven apolar particles on a substrate that organize into an active nematic phase at sufficiently high density or low noise. Using the dynamical renormalization group, we systematically study the 2d fluctuating ordered phase in a coarse-grained hydrodynamic description involving both the nematic director and the conserved density field. In the presence of noise, we show that the system always displays only quasi-long ranged orientational order beyond a crossover scale. A careful analysis of the nonlinearities permitted by symmetry reveals that activity is dangerously irrelevant over the linearized description, allowing giant number fluctuations to persist though now with strong finite-size effects and a non-universal scaling exponent. Nonlinear effects from the active currents lead to power law correlations in the density field thereby preventing macroscopic phase separation in the thermodynamic limit.
Perfect energy transfer and mean-eddy interaction in incompressible fluid flows

The mean-eddy interaction in a flow is investigated in terms of the energy transfer between its mean and eddy processes. In a Reynolds decomposition framework, energy transfer can be defined from the decomposed energy equations, but the definition is subjective with the classical energetics formalism. This paper shows that a faithful formalism can be rigorously established within the same framework. The resulting transfer sums to zero everywhere over the decomposed subspaces, representing a mere redistribution of energy between the mean and eddy processes, without generating or destroying energy as a whole. For this reason, it has been referred to as perfect transfer in distinction from other energy transfers one may have encountered. The perfect transfer has a simple form in expression, with the introduction of an eddy flow coupled with the mean and eddy processes of the field under concern. The eddy or turbulence production is then totally determined by the divergence of this flow. This formalism has been validated with a well-known barotropic instability model, and a wake control problem. It is expected to be useful for the harnessing of turbulence, in that it may help to identify the best locations to place passive controls, or design the performance functional for active controls.
Natural Oscillations of a Polariton Condensate in a Ring

We have observed oscillations of a polariton condensate in a quasi-one-dimensional ring geometry that correspond to the natural frequency of a rigid pendulum. By comparing the oscillations in energy and density, we conclude that excitons have also traveled with the polaritons around the ring. We also show how the oscillations provide tighter constraints on the direct measurement of the polariton-polariton interaction strength, which is an important parameter for theories of nonlinear optics with polariton systems.
Contemporaneous Ultraviolet and Optical Observations of Direct and Raman-scattered O VI Lines in Symbiotic Stars

Symbiotic stars are binary systems consisting of a hot star, typically a white dwarf, and a cool giant companion. The wind from the cool star is ionized by the radiation from the hot star, resulting in the characteristic combination of sharp nebular emission lines and stellar molecular absorption bands in the optical spectrum. Most of the emission lines are readily identifiable with common ions. However, two strong, broad emission lines at 6825 and 7082 Å defied identification with known atoms and ions. In 1989 Schmid made the case that these long unidentified emission lines resulted from the Raman scattering of the O VI resonance photons at 1032, 1038 Å by neutral hydrogen. We present contemporaneous far-UV and optical observations of direct and Raman-scattered O VI lines for nine symbiotic stars obtained with the Hopkins Ultraviolet Telescope (Astro-2) and various ground-based optical telescopes. The O VI emission lines are present in every instance in which the λλ6825, 7082 lines are present, in support of the Schmid Raman-scattering model. We calculate the scattering efficiencies and discuss the results in terms of the Raman-scattering model. Additionally, we measure the flux of the Fe II fluorescence line at 1776 Å, which is excited by the O VI line at 1032 Å, and calculate the first estimates of the conversion efficiencies for this process.
Motion of vortices in inhomogeneous Bose-Einstein condensates

We derive a general and exact equation of motion for a quantized vortex in an inhomogeneous two-dimensional Bose-Einstein condensate. This equation expresses the velocity of a vortex as a sum of local ambient density and phase gradients in the vicinity of the vortex. We perform Gross-Pitaevskii simulations of single-vortex dynamics in both harmonic and hard-walled disk-shaped traps, and find excellent agreement in both cases with our analytical prediction. The simulations reveal that, in a harmonic trap, the main contribution to the vortex velocity is an induced ambient phase gradient, a finding that contradicts the commonly quoted result that the local density gradient is the only relevant effect in this scenario. We use our analytical vortex velocity formula to derive a point-vortex model that accounts for both density and phase contributions to the vortex velocity, suitable for use in inhomogeneous condensates. Although good agreement is obtained between Gross-Pitaevskii and point-vortex simulations for specific few-vortex configurations, the effects of nonuniform condensate density are in general highly nontrivial, and are thus difficult to efficiently and accurately model using a simplified point-vortex description.
Subspace-based optimization method for inverse scattering problems with an inhomogeneous background medium

This paper proposes a version of the subspace-based optimization method to solve the inverse scattering problem with an inhomogeneous background medium where the known inhomogeneities are bounded in a finite domain. Although the background Green's function at each discrete point in the computational domain is not directly available in an inhomogeneous background scenario, the paper uses the finite element method to simultaneously obtain the Green's function at all discrete points. The essence of the subspace-based optimization method is that part of the contrast source is determined from the spectrum analysis without using any optimization, whereas the orthogonally complementary part is determined by solving a lower dimension optimization problem. This feature significantly speeds up the convergence of the algorithm and at the same time makes it robust against noise. Numerical simulations illustrate the efficacy of the proposed algorithm. The algorithm presented in this paper finds wide applications in nondestructive evaluation, such as through-wall imaging.
Ge on Si p-i-n photodiodes operating at 10Gbit∕s

We report on fast p-i-n photodetectors operating in the near infrared and realized in pure germanium on silicon. The diodes were fabricated by chemical vapor deposition at 600°C without affecting the crystal quality and allowing the integration with standard silicon processes. We demonstrate responsivities of 0.4 and 0.2A∕W at 1.3 and 1. 55μm, respectively, as well as operation at 10Gbit∕s.
Deep Neural Networks Applied to Forecast 60 Co Soil-Plant Transfer Factor Values Using Pedological Parameters

The transfer of radionuclides from soil to plants determines the extent of food contamination and, consequently, the risk of radioactive exposure. Soil-plant transfer factor (F v ) is an essential parameter for dose calculation due to ingestion of contaminated food, expressed by the ratio of the mass activity concentration of the plant to that of the soil. Different soil types and plant species result in a large variability in F v values for a single radionuclide. According to the literature, the main soil properties that could influence 60 Co F v are: mineralogy, texture, cation exchange capacity (CEC), soil organic matter (SOM), pH and nutrients. In this work, Artificial Neural Networks (ANN) was applied to evaluate the possibility to forecast 60 Co F v values based on edaphological indicators. The literature review conducted to struture 60 Co F v learning sets for radish root and radish leaf, using pH, SOM and CEC as edaphological indicators. This work showed that only deep neural networks (DNN) architecture with regularization layers was able to predict 60 Co F v values, using the three selected indicators. It was demonstrated by higher correlation for the training set (r=0.9996; n=17), as well for the validation (r=0.9997; n=20), for radish root, both sets with very low mean square errors. This architecture applied for radish leaves also showed good performance, despite the lower data number (n=15). The better performance of DNN was associated with the complexity of interaction between the three pedological parameters available for training, the size of the learning set and the appropriate edaphological indicators for 60 Co.
The Discrepancy between Einstein Mass and Dynamical Mass for SIS and Power-law Mass Models

We investigate the discrepancy between the two-dimensional projected lensing mass and the dynamical mass for an ensemble of 97 strong gravitational lensing systems discovered by the Sloan Lens ACS Survey, the BOSS Emission-Line Lens Survey (BELLS), and the BELLS for GALaxy-Lyα EmitteR sYstems Survey. We fit the lensing data to obtain the Einstein mass and use the velocity dispersion of the lensing galaxies provided by the Sloan Digital Sky Survey to get the projected dynamical mass within the Einstein radius by assuming the power-law mass approximation. The discrepancy is found to be obvious and quantified by Bayesian analysis. For the singular isothermal sphere mass model, we obtain that the Einstein mass is 20.7% more than the dynamical mass, and the discrepancy increases with the redshift of the lensing galaxies. For the more general power-law mass model, the discrepancy still exists within a 1σ credible region. We suspect the main reason for this discrepancy is mass contamination, including all invisible masses along the line of sight. In addition, the measurement errors and the approximation of the mass models could also contribute to the discrepancy.
Spectropolarimetric NLTE inversion code SNAPI

Context. Inversion codes are computer programs that fit a model atmosphere to the observed Stokes spectra, thus retrieving the relevant atmospheric parameters. The rising interest in the solar chromosphere, where spectral lines are formed by scattering, requires developing, testing, and comparing new non-local thermal equilibrium (NLTE) inversion codes. Aims. We present a new NLTE inversion code that is based on the analytical computation of the response functions. We named the code SNAPI, which is short for spectropolarimetic NLTE analytically powered inversion. Methods. SNAPI inverts full Stokes spectrum in order to obtain a depth-dependent stratification of the temperature, velocity, and the magnetic field vector. It is based on the so-called node approach, where atmospheric parameters are free to vary in several fixed points in the atmosphere, and are assumed to behave as splines in between. We describe the inversion approach in general and the specific choices we have made in the implementation. Results. We test the performance on one academic problem and on two interesting NLTE examples, the Ca II 8542 and Na I D spectral lines. The code is found to have excellent convergence properties and outperforms a finite-difference based code in this specific implementation by at least a factor of three. We invert synthetic observations of Na lines from a small part of a simulated solar atmosphere and conclude that the Na lines reliably retrieve the magnetic field and velocity in the range −3 < logτ < −0.5.
An improved dynamic subgrid-scale model and its application to large eddy simulation of stratified channel flows

In the present paper, a new dynamic subgrid-scale (SGS) model of turbulent stress and heat flux for stratified shear flow is proposed. Based on our calculated results of stratified channel flow, the dynamic subgrid-scale model developed in this paper is shown to be effective for large eddy simulation (LES) of stratified turbulent shear flows. The new SGS model is then applied to the LES of the stratified turbulent channel flow to investigate the coupled shear and buoyancy effects on the behavior of turbulent statistics, turbulent heat transfer and flow structures at different Richardson numbers.
Measuring the baryon fraction in cluster of galaxies with kinematic Sunyaev Zeldovich and a Standard Candle

We propose a new method to use the kinematic Sunyaev-Zeldovich for measuring the baryon fraction in cluster of galaxies. In this proposal we need a configuration in which a supernova Type Ia resides in a brightest cluster galaxy of intermediate redshift clusters. We show this supernova Type Ia can be used to measure the bulk velocity of a galaxy cluster. We assert that the redshift range of 0.4<z<0.6 is suitable for this proposal. The main contribution to the deviation of standard candles distance modulus from cosmological background prediction in this redshift range comes from peculiar velocity of the host galaxy and gravitational lensing. In this work we argue that by the knowledge of the bulk flow of the galaxy cluster and the cosmic microwave background photons temperature change due to kinematic Sunyaev-Zeldovich, we can constrain the baryon fraction of galaxy cluster. The probability of this configuration for clusters is obtained. We estimate in a conservative parameter estimation the large synoptic survey telescope can find spectroscopically followed ∼ 4500 galaxy clusters with a bright cluster galaxy which hosts a type Ia Supernova each year. Finally, we show the improving of the distance modulus measurement is the key improvement in future surveys which will be crucial to detect the baryon fraction of cluster with the proposed method.
The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

The flat spectrum radio quasar CTA 102 ( z = 1 . 032 ) went through a tremendous phase of variability. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a four month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have explained the giant outburst as the ablation of a gas cloud by the relativistic jet that injects additional matter into the jet and can self-consistently explain the long-term light curve. Here, we argue that the cloud responsible for the giant outburst is part of a larger system that collides with the jet and is responsible for the years-long activity in CTA 102.