Miracle-dz/UniFAR-FTUs huggingface dataset:
Roles of Photospheric Motions and Flux Emergence in the Major Solar Eruption on 2017 September 6

We study the magnetic field evolution in the active region (AR) 12673 that produced the largest solar flare in the past decade on 2017 September 6. Fast flux emergence is one of the most prominent features of this AR. We calculate the magnetic helicity from photospheric tangential flows that shear and braid field lines (shear helicity) and from normal flows that advect twisted magnetic flux into the corona (emergence helicity), respectively. Our results show that the emergence helicity accumulated in the corona is −1.6 × 1043 Mx2 before the major eruption, while the shear helicity accumulated in the corona is −6 × 1043 Mx2, which contributes about 79% of the total helicity. The shear-helicity flux is dominant throughout the overall investigated emergence phase. Our results imply that the emerged fields initially contain relatively low helicity. Much more helicity is built up by shearing and converging flows acting on preexisting and emerging flux. Shearing motions are getting stronger with the flux emergence, and especially on both sides of the polarity inversion line of the core field region. The evolution of the vertical currents shows that most of the intense currents do not appear initially with the emergence of the flux, which implies that most of the emerging flux is probably not strongly current carrying. The helical magnetic fields (flux rope) in the core field region are probably formed by long-term photospheric motions. The shearing and converging motions are continuously generated, driven by the flux emergence. AR 12673 is representative, as photospheric motions contribute most of the nonpotentiality in the AR with vigorous flux emergence.
Estimation of macrodispersion in 2‐D highly heterogeneous porous media using the Eulerian‐Lagrangian localized adjoint method

The Eulerian‐Lagrangian localized adjoint method (ELLAM) formulation of Younes et al. (2006) is applied to solve the advection‐dispersion equation used to describe conservative solute transport in highly heterogeneous porous media. Heterogeneity is described by a correlated random field with an exponential covariance. Macrodispersion coefficients are calculated for a broad range of heterogeneities using Monte Carlo (MC) simulations on large size domains. ELLAM circumvents some drawbacks of usual particle‐tracking and Eulerian‐Lagrangian methods when local dispersion/diffusion is added. ELLAM is also highly efficient and well adapted for advective dominant transport and for MC simulations. For pure advection, first‐order approximation provides good estimates of the duration of the preasymptotic regime and of the longitudinal macrodispersion coefficient for a variance of the log conductivity σ2≤2.25 . Higher‐order theories overestimated this coefficient for higher variances. Computed transverse macrodispersion is equal to 0 for each studied variance of log conductivity σ2∈[ 0.25,1.0,2.25,4.0,6.25,9.0 ] . Local dispersion/diffusion affects the macrodispersion for quite low Peclet number (<100) compared to previous work. For a Peclet number of 10, it leads to an increase of the longitudinal and transverse macrodispersion for low variances ( σ2=0.25 ). For higher heterogeneity ( σ2=9.0 for local dispersion and σ2≥4.0 for local diffusion), the longitudinal macrodispersion decreases due to local transverse mixing.
FUNDAMENTAL THEOREMS ON THE EXTENSION OF HERMITIAN OPERATORS AND SOME OF THEIR APPLICATIONS TO THE THEORY OF ORTHOGONAL POLYNOMIALS AND TO THE PROBLEM OF MOMENTS

Abstract : Presented are various theorems on the extension of operators with a systematic use of a linear-fractional transformation of a linear operator. Also shown is that every Hermitian operator with dense domain of definition which has a spectral gap admits a self-adjoint extension and preserves the gap. The invariance of defect indices in the upper and lower half planes is proven for the case of arbitrary linear operators. Fundamental concepts dealing with linear operators in a Hilbert space are presented. Various examples appear throughout the paper showing the application of the derived theorems. They are taken from the theory of orthogonal polynomials and the problem of moments. (Author)
Kronecker representation of stochastic Petri nets with discrete PH distributions

In recent years, several classes of Stochastic Petri Net (SPN) models have been elaborated which incorporate some non-exponential characteristics in their definition. Among the various approaches that have been proposed in the literature for handling non-exponential SPNs, the paper investigates the class of models in which the firing time assigned to each transition is a Discrete Phase Type (DPH) random variable, so that the evolution of the marking process is mapped into an expanded discrete-time Markov chain (DTMC). In order to alleviate the state space explosion problem, the expanded state space is expressed via Kronecker algebra operators, starting from the knowledge of the reachability graph of the untimed PN and the DPH random firing times assigned to each PN-transition. The discrete case is very appealing since it allows to mix distributions with finite and infinite support. However the problem of simultaneous firings arises, and the related semantics must be carefully considered.
The evolution of intermediate-mass protostars. I, Basic results

A numerical calculation of the structure and evolution of Population I protostars in the range from 1 to 8 solar masses is presented. The protostar is modeled as being built up from a spherically symmetric accretion flow, with a constant mass accretion rate of 0.00001 solar mass/yr. The protostar is initially fully convective due to the steady state burning of deuterium near its center. The mass-radius relation during this phase is derived analytically. At 2.4 solar masses, a radiative barrier appears which prevents the convective transport of deuterium to the center. The subsurface shell is ignited by the deuterium, which causes the protostar to swell. The star joins the zero-age main sequence by the time it reaches 8 solar masses. It is found that over a significant mass range, protostars contain a substantial amount of deuterium, and it is inferred that the ignition of this fuel during subsequent premain-sequence contraction could drive the surface convection that is apparently present in many Herbig Ae and Be stars. 35 refs.
Search for H3+ in HD 141569A

A search for H line emission, reported to have been detected toward the young star HD 141569A and possibly originating in a clump of planet-forming gas orbiting the star, has yielded negative results. Observations made at the United Kingdom Infrared Telescope and the Subaru Telescope during 2001-2005 covered 11 major transitions of H from 3.42 to 3.99 μm. No H emission lines were detected; one marginal detection at 3.9855 μm in 2002 June was not confirmed in later spectra. The upper limits to the line strengths were significantly lower than the previously reported detections. Supplemental slit-scanning spectroscopy using adaptive optics was performed within 0. ″38 of HD 141569A to search for extended emission from H, but no emission was detected. We compare our upper limit to the luminosity in H from HD 141569A with that possible from a gas giant protoplanet and also from a jovian mass exoplanet in close orbit about its central star.
Kinetic Effects on Turbulence Driven by the Magnetorotational Instability in Black Hole Accretion

Magnetorotational Instability (MRI), the instability causing turbulent transport in accretion disks, is studied in the kinetic regime. Radiatively Inefficient Accretion Flows (RIAFs), like the one around the supermassive black hole in the center of our Galaxy, are believed to be collisionless. Kinetic MHD formalism, based on the moments of the Vlasov equation, is used for linear analysis and nonlinear simulations. ZEUS MHD code is modified to include key kinetic MHD terms: anisotropic pressure tensor and anisotropic thermal conduction. Simulations use the local shearing box approximation. Pressure anisotropy is created, because of the adiabatic invariance ($\mu=p_\perp/B$), as magnetic field is amplified by the MRI. Larmor radius scale instabilities--mirror, ion-cyclotron, and firehose--are excited at large pressure anisotropy. Pressure isotropization due to pitch angle scattering by these instabilities is included as a subgrid model. A key result of the kinetic MHD simulations is that the anisotropic (viscous) stress can be as large as the Maxwell stress. A new numerical method to simulate anisotropic thermal conduction with large temperature gradients is suggested. Simple tests show that the centered differencing of anisotropic thermal conduction can result in heat flowing from lower to higher temperatures, giving rise to negative temperatures. Limiting of transverse temperature gradients does not accentuate temperature extrema.
The Evolution of the Galaxy Luminosity Function in the Rest-Frame Blue Band up to z = 3.5

We present an estimate of the cosmological evolution of the field galaxy luminosity function (LF) in the rest-frame 4400 Å B band up to redshift z = 3.5. To this purpose, we use a composite sample of 1541 I-selected galaxies selected down to IAB = 27.2 and 138 galaxies selected down to KAB = 25 from ground-based and HST multicolor surveys, most notably the new deep JHK images in the Hubble Deep Field-South (HDF-S) taken with the ISAAC instrument at the ESO-VLT telescope. About 21% of the sample has spectroscopic redshifts, and the remaining fraction well-calibrated photometric redshifts. The resulting blue LF shows little density evolution at the faint end with respect to the local values, while at the bright end [MB(AB) < -20] a brightening increasing with redshift is apparent with respect to the local LF. Hierarchical CDM models overpredict the number of faint galaxies by a factor ~3 at z ≃ 1. At the bright end the predicted LFs are in reasonable agreement only at low and intermediate redshifts (z ≃ 1) but fail to reproduce the pronounced brightening observed in the high-redshift (z ~ 2-3) LF. This brightening could mark the epoch at which major star formation activity is present in the galaxy evolution.
Fixed point stability and decay of correlations

In the framework of the renormalization-group (RG) theory of critical phenomena, a quantitative description of many continuous phase transitions can be obtained by considering an effective Φ4 theories, having an N-component fundamental field Φi and containing up to fourth-order powers of the field components. Their RG flow is usually characterized by several fixed points (FPs). We give here strong arguments in favour of the following conjecture: the stable FP corresponds to the fastest decay of correlations, that is, is the one with the largest values of the critical exponent η describing the power-law decay of the two-point function at criticality. We prove this conjecture in the framework of the ε-expansion. Then, we discuss its validity beyond the ε-expansion. We present several lower-dimensional cases, mostly three-dimensional, which support the conjecture. We have been unable to find a counterexample.
Maternal Metformin Treatment Reprograms Maternal High-Fat Diet-Induced Hepatic Steatosis in Offspring Associated with Placental Glucose Transporter Modifications

Maternal high-fat (HF) diet exposure in utero may affect fetal development and cause metabolic problems throughout life due to lipid dysmetabolism and oxidative damage. Metformin has been suggested as a potential treatment for body weight reduction and nonalcoholic fatty liver disease, but its reprogramming effect on offspring is undetermined. This study assesses the effects of maternal metformin treatment on hepatic steatosis in offspring caused by maternal HF diet. Female rats were fed either a control or an HF diet before conception, with or without metformin treatment during gestation, and placenta and fetal liver tissues were collected. In another experiment, the offspring were fed a control diet until 120 d (adult stage). Metformin treatment during pregnancy ameliorates placental oxidative stress and enhances placental glucose transporter 1 (GLUT1), GLUT3, and GLUT4 expression levels through 5’ adenosine monophosphate-activated protein kinase (AMPK) activation. Maternal metformin treatment was shown to reprogram maternal HF diet-induced changes in offspring fatty liver with the effects observed in adulthood as well. Further validation is required to develop maternal metformin therapy for clinical applications.
Optical Trapping Forces on Non-Spherical Particles in Fluid Flows

The optical stability of particles above a waveguide surface depends on the forces induced by fluid drag and the electromagnetic field. The optical trapping forces on non-spherical particles were examined for various flow conditions. A three-dimensional finite element method was employed to calculate the electromagnetic field and the fluid flow. It was found that the stability of non-spherical particles is significantly affected by the fluid velocity and the orientation of the particles. The downward trapping force meant that non-spherical particles are more stable at higher Reynolds numbers. The length of the particle in the transverse direction also had a significant impact on particle stability. The present model was tested against previously reported results.
Entanglement Entropy: Helicity versus Spin

For a massive spin 1/2 field, we present the reduced spin and helicity density matrix, respectively, for the same pure one particle state. Their relation has also been developed. Furthermore, we calculate and compare the corresponding entanglement entropy for spin and helicity within the same inertial reference frame. Due to the distinct dependence on momentum degree of freedom between spin and helicity states, the resultant helicity entropy is different from that of spin in general. In particular, we find that both helicity entanglement for a spin eigenstate and spin entanglement for a right handed or left handed helicity state do not vanish and their Von Neumann entropy has no dependence on the specific form of momentum distribution as long as it is isotropic.
Mobility gap in intermediate valent TmSe

The infrared optical conductivity of the intermediate-valence compound TmSe reveals clear signatures for hybridization of light d- and heavy f-electronic states with m* ≈ 1.6m0 and m* ≈ 16m0, respectively. At moderate and high temperatures, the metal-like character of the heavy carriers dominates the low-frequency response while at low temperatures (TN < T < 100 K) a gap-like feature is observed in the conductivity spectra below 10 meV which is assigned to be a mobility gap due to localization of electrons on local Kondo singlets, rather than a hybridization gap in the density of states.
High-Precision Stellar Radial Velocities in the Galactic Center

We present radial velocities for 85 cool stars projected onto the central parsec of the Galaxy. The majority of these velocities have relative errors of ~1 km s-1, or a factor of ~30-100 smaller than those previously obtained with proper-motion or other radial velocity measurements for a similar stellar sample. The error in a typical individual stellar velocity, including all sources of uncertainty, is 1.7 km s-1. Two similar data sets were obtained 1 month apart, and the total error in the relative velocities is 0.80 km s-1 in the case where an object is common to both data sets. The data are used to characterize the velocity distribution of the old population in the Galactic center. We find that the stars have a Gaussian velocity distribution with a mean heliocentric velocity of -10.1 ± 11.0 km s-1 (blueshifted) and a standard deviation of 100.9 ± 7.7 km s-1; the mean velocity of the sample is consistent with no bulk line-of-sight motion with respect to the local standard of rest. At the 1 σ level, the data are consistent with a symmetric velocity distribution about any arbitrary axis in the plane of the sky. We find evidence for a flattening in the distribution of late-type stars within a radius of ~0.4 pc and infer a volume density distribution of r-1/4 in this region. Finally, we establish a first epoch of radial velocity measurements that can be compared with subsequent epochs to measure small accelerations (1 km s-1 yr-1), corresponding to the magnitude expected over a time span of several years for stars nearest to Sgr A*.
Exact Coherent States of a Harmonically Confined Tonks-Girardeau Gas

Using a scaling transformation we exactly determine the dynamics of an harmonically confined Tonks-Girardeau gas under arbitrary time variations of the trap frequency. We show how during a one-dimensional expansion a 'dynamical fermionization' occurs as the momentum distribution rapidly approaches an ideal Fermi gas distribution, and that under a sudden change of the trap frequency the gas undergoes undamped breathing oscillations displaying alternating bosonic and fermionic character in momentum space. The absence of damping in the oscillations is a peculiarity of the truly Tonks regime.
Seasonal changes of the volatile density in the coma and on the surface of comet 67P/Churyumov–Gerasimenko

Starting from several monthly data sets of Rosetta’s COmetary Pressure Sensor, we reconstruct the gas density in the coma around comet 67P/Churyumov–Gerasimenko. The underlying inverse gas model is constructed by fitting ten thousands of measurements to thousands of potential gas sources distributed across the entire nucleus surface. The ensuing self-consistent solution for the entire coma density and surface activity reproduces the temporal and spatial variations seen in the data for monthly periods with Pearson correlation coefficients of 0.93 and higher. For different seasonal illumination conditions before and after perihelion, we observe a systematic shift of gas sources on the nucleus.
Ginga observations of the Coma cluster and studies of the spatial distribution of iron

The large area counters on the Japanese satellite Ginga have been used to determine the X-ray spectrum from the central region of the Coma cluster of galaxies over the energy range from 1.5 to 20 keV. The spectrum is well represented by an isothermal model of temperature 8.21 +/- 0.16 keV and a heavy element (iron) abundance of 0.212 +/- 0.027, relative to the cosmic value. The Ginga spectrum was found to be consistent with the X-ray spectra from the Tenma and EXOSAT satellites for a large class of nonisothermal temperature distributions. The measured iron elemental abundances were used to set a lower limit on the total mass of iron in Coma under the assumption that the iron is not distributed uniformly throughout the cluster. The mass ratio of iron relative to hydrogen (within 2 Mpc) is not less than 18 percent of the cosmic iron to hydrogen mass ratio. This compares to an average abundance of 24 percent if the iron is distributed uniformly. We discuss these results in terms of models for the production of iron in galaxy clusters.
A Large Local Rotational Speed for the Galaxy Found from Proper Motions: Implications for the Mass of the Milky Way

Predictions from a Galactic structure and kinematic model are compared with the absolute proper motions of about 30,000 randomly selected stars with 9 < BJ ≤ 19 derived from the Southern Proper-Motion (SPM) program toward the south Galactic pole. The absolute nature of the SPM proper motions allows us to measure not only the relative motion of the Sun with respect to the local disk but also, and most importantly, the overall state of rotation of the local disk with respect to galaxies. The SPM data are best fitted by models having a solar peculiar motion of 5 km s-1 in the V-component (pointing in the direction of Galactic rotation), a large LSR speed of 270 km s-1, and a disk velocity ellipsoid that points toward the Galactic center. We stress, however, that these results rest crucially on the assumptions of both axisymmetry and equilibrium dynamics. The absolute proper motions in the U-component indicate a solar peculiar motion of 11.0 ± 1.5 km s-1, with no need for a local expansion or contraction term. The implications of the large LSR speed are discussed in terms of the gravitational mass of the Galaxy inferred from the most recent and accurate determination for the proper motion of the LMC. We find that our derived value for the LSR is consistent both with the mass of the Galaxy inferred from the motion of the Clouds [(3-4) × 1012 M☉ to ~50 kpc] and with the timing argument, based on the binary motion of M31 and the Milky Way and on that of Leo I and the Milky Way (≥1.2 × 1012 M☉ to ~200 kpc).
The Lower bound on the neutralino nucleon cross-section

We examine if there is a lower bound on the direct detection cross section for the neutralino dark matter in the MSSM. If we impose the minimal supergravity boundary conditions as well as the "naturalness" condition, in particular m_{1/2} < 300 GeV, we show that there is a lower bound of 10^{-46}cm^2 on the cross section for neutralino scattering off of a proton. We also clarify the origin for the lower bound. Relaxing either of the assumptions, however, can lead to much smaller cross sections.
Lifetimes of the 5d 9 6p levels in Au ii

We report experimental lifetimes for 11 of the 12 5d96p levels of Au ii, determined by means of the beam-foil excitation method. The data are compared with theoretical calculations based on the Cowan group of programs. These first studies of Au ii lifetimes and transition probabilities were motivated largely by the need for such data in the analysis of high-resolution stellar spectroscopy done with the Goddard High-Resolution Spectrograph on the Hubble Space Telescope.
Use of two scaling relations in the study of multiple-scattering effects on the transmittance of light beams through a turbid atmosphere

Monte Carlo methods, used in calculations of the received power in transmissions of collimated light beams through a turbid atmosphere in a multiple-scattering regime, present a shortcoming because of the length of computer time necessary to obtain reliable results. We show how the introduction of two scaling formulas makes a substantial reduction of calculation time possible, since situations differing through the values of some geometrical parameters do not require separate treatment. Two versions of the scaling formulas are presented. The simpler one can be applied when the scattering function of the medium has a high forward peak, so that one can assume that only small scattering angles are important. The second form of the scaling formula can be applied in cases when small-angle assumption is not adequate.
Possible coexistence of rotational and ferroelectric lattice distortions in rhombohedral PbZr x Ti 1 − x O 3

The competitions between ferroelectric and rotational instabilities in rhombohedral ${\mathrm{PbZr}}_{x}{\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{O}}_{3}$ near $x=0.5$ are investigated using first-principles density-functional supercell calculations. As expected, we find a strong ferroelectric instability. However, we also find a substantial R-point rotational instability, close to but not as deep as the ferroelectric one. This is similar to the situation in pure ${\mathrm{PbZrO}}_{3}. $ These two instabilities are both strongly pressure dependent, but in opposite directions so that lattice compression of less than 1% is sufficient to change their ordering. Because of this, and local stress fields due to B-site cation disorder may lead to coexistence of both types of instability are likely present in the alloy near the morphotropic phase boundary.
PREDICTIONS FOR FERMION-PAIR PRODUCTION AT LEP

The status of predictions for fermion-pair production at LEP is summarized withemphasis on LEP2 energies and on the physics interest there. Some numericalcomparisons with other programs are performed. We also present ﬁrst results of asemi-analytical recalculation of photonic corrections with acollinearity cut in theZFITTERapproach.