Miracle-dz/UniFAR-FTUs huggingface dataset:
The study of two barred galaxies with curious kinematical features

We performed long-slit spectral observations of two SB-type galaxies: NGC 5347, UGC 1344. They were previously suspected as the galaxies with unusually low mass-to-light ratios (on the ground of mass estimates from the Hi linewidths), which are in conflict with their observed colours. The observations were conducted at the Russian 6-m telescope. The aim of the study was to clarify the kinematics and structure, as well as the properties of stellar populations of the galaxies. The results of observations disproved the peculiarly low mass-to-light ratios of both galaxies. The most probable reasons of underestimation of their masses are discussed. We tried to reproduce the main observed features of kinematical profiles of the galaxies in the N-body simulations of barred galaxies. We found that both galaxies possess central components of different structure. Indeed, the age and velocity dispersion of stellar population in NGC 5347 are low in its innermost part in comparison to that of the bulge or a bar, which agrees with the presence of nuclear kinematically decoupled disc. It probably was formed due to the bar which supplied the inner region with gas. The kinematical profiles of the second galaxy UGC 1344 give evidences in favour of the central peanut-shaped bulge. In spite of the different luminosities of the two galaxies, they possess nearly equal (close to solar) central stellar abundance and the flattening of the stellar metallicity gradient in the bar regions. However, in the less luminous NGC 5347 the mean stellar age is younger than that in UGC 1344.
Cartography for Martian Trojans

The last few months have seen the discovery of a second Martian Trojan (1998 VF31) as well as two further possible candidates (1998 QH56 and 1998 SD4). Together with the previously discovered Martian satellite 5261 Eureka, these are the only known possible solar system Trojan asteroids not associated with Jupiter. Here maps of the locations of the stable Trojan trajectories of Mars are presented. These are constructed by integrating an ensemble of in-plane and inclined orbits in the vicinity of the Martian Lagrangian points for between 25 and 60 million years. The survivors occupy a band of inclinations between 15° and 40° and longitudes between 240° and 330° at the L5 Lagrangian point. Around the L4 point, stable Trojans inhabit two bands of inclinations (15° < i < 30° and 32° < i < 40°) with longitudes restricted between 25° and 120°. Both 5261 Eureka and 1998 VF31 lie deep within one of the stable zones, which suggests that they may be of primordial origin. Around Mars, the number of such undiscovered primordial objects with sizes greater than 1 km may be as high as ~50. The two candidates 1998 QH56 and 1998 SD4 are not presently on Trojan orbits and will enter the sphere of influence of Mars within half a million years.
Opacity and entanglement of polymer chains

We argue that the mean crossing number of a random polymer configuration is simply a measure of opacity, without being closely related to entanglement as claimed by several authors. We present an easy way of estimating its asymptotic behaviour numerically. These estimates agree for random walks (theta polymers), for self-avoiding walks, and for compact globules with analytic estimates giving log N, a-b/N 2ν-1, and N 1/3, respectively, for the average number of crossings per monomer in the limit N→∞. While the result for compact globules agrees with a rigorous previous estimate, the result for self-avoiding random walks disagrees with previous numerical estimates.
Perception-based image/video quality metric using CIELAB color space

This paper addresses the problem of color image quality assessment. The paper presents a novel image/ video quality metrics, Color-SSIM (color-based structural similarity index), based on CIELAB color model. The main drawback of the SSIM algorithm in the spatial domain is that it is highly sensitive to the translation, rotation and scaling of images. This problem can be solved by applying SSIM to the individual channels of a color image in CIELAB color space and by combining the results from the individual channels into a weighted vector mean. Experimental results show that proposed quality metric is highly correlated with the experimental data collected through subjective experiments.
The gravitational influence of a beam of light. I

In this paper an exact solution is provided for the Einstein field equations of a beam of light. The beam is circular in cross section, infinite in length and duration, and considered in the geometrical limit with the flux being a function of only the radial coordinate. Null and timelike trajectories of this metric are considered in two classes: those with and without angular motion around the circular beam. The elements of the beam are initially without angular or radial motion and are found to follow a set of null trajectories which allows the beam to be in a state of equilibrium. A null trajectory, without angular motion, which is initially inclined slightly to the direction of the beam will curve away from the beam. Such a trajectory will continue to curve away until it is directed perpendicular to and then opposite to the beam direction, thereupon coming back into the beam upon the mirrored outgoing trajectory. Such trajectories are discussed with emphasis upon Lorentz transformations along the direction of the beam. Trajectories with angular motion include orbital cases. Beams of sufficient energy flux may allow closed null orbitals and regions of stable and unstable closed time‐like orbits. Null helical trajectories which spiral back along the length of the beam can always occur; however, forward spiraling trajectories are restricted to large fluxes and are discussed in the light of Lorentz transformations.
Composite graviton self-interactions in a model of emergent gravity

We consider a theory of scalars minimally coupled to an auxiliary background metric. The theory is generally covariant and subject to the constraint of vanishing energy-momentum tensor. Eliminating the auxiliary metric leads to a reparametrization invariant, non-polynomial, metric-independent action for the scalar fields. Working in the limit of a large number of physical scalars, a composite massless spin-2 state, the graviton, was identified in previous work, in a two-into-two scalar scattering process. Here, we further explore the possibility that dynamical emergent gravity is a natural feature of generally covariant quantum field theories, by studying the self-interactions of the emergent composite graviton. We show that the fine-tuning previously imposed to ensure the vanishing of the cosmological constant, as well as the existence of the massless spin-2 state, also assures that the emergent graviton's cubic self-interactions are consistent with those of Einstein's general relativity, up to higher-derivative corrections. We also demonstrate in a theory with more than one type of scalar that the composite graviton coupling is universal.
Orbital magnetism in the half-metallic Heusler alloys

Using the fully-relativistic screened Korringa-Kohn-Rostoker method I study the orbital magnetism in the half-metallic Heusler alloys. Orbital moments are almost completely quenched and they are negligible with respect to the spin moments. The change in the atomic-resolved orbital moments can be easily explained in terms of the spin-orbit strength and hybridization effects. Finally I discuss the orbital and spin moments derived from X-ray magnetic circular dichroism experiments.
On the joint preprocessing techniques for OFDM-based cooperative network MIMO systems

Next-generation (4G) systems are designed to support universal frequency reuse (UFR) and adopt orthogonal frequency-division multiplexing (OFDM) to achieve best use of their valuable spectra. Unfortunately, the implementation of UFR leads to unacceptable interference levels near cell borders. To control this, 4G systems adopt network multiple-input multiple-output (MIMO), an elaborate coordination among adjacent cells, to improve coverage and cell-edge throughput. Unfortunately, for multi-cell coordination, most studies on this subject have examined the corresponding information-theoretic capacities and only a few joint preprocessing schemes have been investigated for narrowband non-OFDM-based systems in flat fading channels. Instead of information-theoretic capacity, this paper derives various joint preprocessing techniques for OFDM-based network MIMO in wideband multipath fading channels. They include joint time-division multiple access (J-TDMA), joint zero-forcing (J-ZF), joint minimum mean square error (J-MMSE), and joint null-space decomposition (J-NSD). The J-TDMA scheme is free from co-channel interference (CCI) at the cost of spectral efficiency. The J-ZF scheme enables complete suppression of interference, but demands higher transmitter power for the precoding process. The J-MMSE yields a performance close to the CCI-free J-TDMA scheme, by making an acceptable compromise between interference suppression and transmitter power efficiency. In J-NSD, the CCI is completely removed, but signal transmission is confined to a reduced subspace.
Self-organization of charged particles on a two-dimensional lattice subject to anisotropic Jahn-Teller-type interaction and three-dimensional Coulomb repulsion

Self-organization of charged particles on a two-dimensional lattice, subject to an anisotropic Jahn-Teller-type interaction and three-dimensional Coulomb repulsion, is investigated. In the mean-field approximation without Coulomb interaction, the system displays a phase transition of first order. In the presence of the Coulomb repulsion, the global phase separation becomes unfavorable and the system shows a mesoscopic phase separation, where the size of the charged regions is determined by the competition between the ordering energy and the Coulomb energy. The phase diagram of the system as a function of particle density and temperature is obtained by systematic Monte Carlo simulations. With decreasing temperature, a crossover from a disordered state to a state composed of mesoscopic charged clusters is observed. In the phase separated state, charged clusters with even number of particles are more stable than those with odd number of particles in a large range of particle densities. With increasing particle density at low temperatures, a series of crossovers between states with different cluster sizes is observed. Above half-filling, in addition to the low temperature clustering, another higher temperature scale, which corresponds to orbital ordering of particles, appears. We suggest that the diverse functional behavior observed in transition metal oxides can be thought to arise from the self-organization of this type.
Quantifying the (X/peanut)-shaped structure of the Milky Way – new constraints on the bar geometry

The nature, size and orientation of the dominant structural components in the Milky Way's inner ~4 kpc - specifically the bulge and bar - have been the subject of conflicting interpretations in the literature. We present a different approach to inferring the properties of the long bar which extends beyond the inner bulge, via the information encoded in the Galaxy's X/peanut (X/P)-shaped structure. We perform a quantitative analysis of the X/P feature seen in WISE wide-field imaging at 3.4 $\mu$m and 4.6 $\mu$m. We measure the deviations of the isophotes from pure ellipses, and quantify the X/P structure via the radial profile of the Fourier n=6 harmonic (cosine term $B_6$). In addition to the vertical height and integrated `strength' of the X/P instability, we report an intrinsic radius of $R_{\Pi;{\rm int}} = 1.67\pm0.27$ kpc, and an orientation angle of $\alpha = {37^\circ}^{+7^\circ}_{-10^\circ}$ with respect to our line-of-sight to the Galactic Centre. Based on X/P structures observed in other galaxies, we make three assumptions: (i) the peanut is intrinsically symmetric, (ii) the peanut is aligned with the long Galactic bar, and (iii) their sizes are correlated. Thus the implication for the Galactic bar is that it is oriented at the same $37^\circ$ angle and has an expected radius of ~4.2 kpc, but possibly as low as ~3.2 kpc. We further investigate how the Milky Way's X/P structure compares with other analogues, and find that the Galaxy is broadly consistent with our recently established scaling relations, though with a moderately stronger peanut instability than expected. We additionally perform a photometric decomposition of the Milky Way's major axis surface brightness profile, accounting for spiral structure, and determine an average disc scale length of $h = 2.54\pm0.16$ kpc in the WISE bands, in good agreement with the literature.
Fermions in the Ashtekar-Barbero connection formalism for arbitrary values of the Immirzi parameter

The Ashtekar-Barbero-Immirzi formulation of general relativity is extended to include spinor matter fields. Our formulation applies to generic values of the Immirzi parameter and reduces to the Ashtekar-Romano-Tate approach when the Immirzi parameter is taken equal to the imaginary unit. The dynamics of the gravity-fermions coupled system is described by the Holst plus Dirac action with a nonminimal coupling term. The nonminimal interaction together with the Holst modification to the Hilbert-Palatini action reconstruct the Nieh-Yan invariant, so that the effective action coming out is the one of Einstein-Cartan theory with a typical Fermi-like interaction term: in spite of the presence of spinor matter fields, the Immirzi parameter plays no role in the classical effective dynamics and results to be only a multiplicative factor in front of a total divergence. We reduce the total action of the theory to the sum of dynamically independent Ashtekar-Romano-Tate actions for self and anti-self-dual connections, with different weights depending on the Immirzi parameter. This allows to calculate the constraints of the complete theory in a simple way, it is only necessary to realize that the Barbero-Immirzi connection is a weighted sum of the self and anti-self-dual Ashtekar connections. Finally the obtained constraints for the separated action result to be polynomial in terms of the self and anti-self-dual connections, this could have implications in the inclusion of spinor matter in the framework of nonperturbative quantum gravity.
A Negative Index Meta-Material for Maxwell's Equations

We derive the homogenization limit for time harmonic Maxwell's equations in a periodic geometry with periodicity length $\eta>0$. The considered meta-material has a singular sub-structure: the permittivity coefficient in the inclusions scales like $\eta^{-2}$ and a part of the substructure (corresponding to wires in the related experiments) occupies only a volume fraction of order $\eta^2$; the fact that the wires are connected across the periodicity cells leads to contributions in the effective system. In the limit $\eta\to 0$, we obtain a standard Maxwell system with a frequency dependent effective permeability $\mu^{\mathrm{eff}}(\omega)$ and a frequency independent effective permittivity $\varepsilon^{\mathrm{eff}}$. Our formulas for these coefficients show that both coefficients can have a negative real part, the meta-material can act like a negative index material. The magnetic activity $\mu^{\mathrm{eff}}\neq 1$ is obtained through dielectric resonances as in previous publications. The wires are thin enough to be magnetically invisible, but, due to their connectedness property, they contribute to the effective permittivity. This contribution can be negative due to a negative permittivity in the wires.
Thermodynamics of Global Optimization

Theoretical design of global optimization algorithms can profitably utilize recent statistical mechanical treatments of potential energy surfaces (PES's). Here we analyze a particular method to explain its success in locating global minima on surfaces with a multiple-funnel structure, where trapping in local minima with different morphologies is expected. We find that a key factor in overcoming trapping is the transformation applied to the PES which broadens the thermodynamic transitions. The global minimum then has a significant probability of occupation at temperatures where the free energy barriers between funnels are surmountable.
Dynamics of deformable mirror actuators

The electro-mechanical equations governing the motion of the surface of a deformable mirror, due to the activation of a piezoelectric or electrostrictive actuator mechanically located between the mirror surface and the mirror substrate, are derived in terms of the fundamental electro-mechanical parameters of the mirror-actuator configuration. The equations of motion are solved in the frequency domain and the solutions show reasonable agreement with experimental data such as Bode plots, which characterize the frequency dependence of the amplitude and phase of the mirror surface motion, and with frequency dependent impedance measurements. Time domain solutions are used to construct time histories of an actuator under a step-voltage input.
Field dependent permittivity of composite materials containing ferromagnetic wires

A type of a composite material is proposed, the microwave permittivity of which changes under the effect of a dc magnetic field applied to the whole composite sample. The composite consists of short ferromagnetic wires embedded into a dielectric matrix. A strong field dependence of the permittivity is seen in the vicinity of the antenna resonance, where the dispersion behavior can experience a transformation from a resonant spectrum to a relaxation one under the effect of the field. This permittivity behavior is due to a high sensitivity of the ac surface impedance of a ferromagnetic wire to a magnetic field, known as the magnetoimpedance (MI) effect. If the resonance-like dispersion behavior is realized, the real part of the effective permittivity can be made negative past the resonance for wire inclusion concentrations well below the percolation threshold. Applying a magnetic field, the negative peak continuously decreases as the dispersion tends to become of a relaxation type. The effective permittivit.
Conformal Sequestering Simplified

Sequestering is important for obtaining flavor-universal soft masses in models where supersymmetry breaking is mediated at high scales. We construct a simple and robust class of hidden sector models which sequester themselves from the visible sector due to strong and conformally invariant hidden dynamics. Masses for hidden matter eventually break the conformal symmetry and lead to supersymmetry breaking by the mechanism recently discovered by Intriligator, Seiberg and Shih. We give a unified treatment of subtleties due to global symmetries of the CFT. There is enough review for the paper to constitute a self-contained account of conformal sequestering.
Monitoring of the Prompt Radio Emission from the Unusual Supernova SN 2004dj in NGC 2403

Supernova SN 2004dj in the nearby spiral galaxy NGC 2403 was detected optically in 2004 July. Peaking at a magnitude of 11.2, this is the brightest supernova detected for several years. Here we present Multi-Element Radio Linked Interferometer Network (MERLIN) observations of this source, made over a 4 month period, that give a position of R.A. = 07h37m17. ˢ044, decl. = +65°35'57. ″84 (J2000.0). We also present a well-sampled 5 GHz light curve covering the period from 2004 August 5 to December 2. With the exception of the unusual and very close SN 1987A, these observations represent the first detailed radio light curve for the prompt emission from a Type II-P supernova.
Superconducting fluctuations at arbitrary disorder strength

We study the effect of superconducting fluctuations on the conductivity of metals at arbitrary temperatures $T$ and impurity scattering rates $\tau^{-1}$. Using the standard diagrammatic technique but in the Keldysh representation, we derive the general expression for the fluctuation correction to the dc conductivity applicable for any space dimensionality and analyze it the case of the film geometry. We observe that the usual classification in terms of the Aslamazov-Larkin, Maki-Thompson and density-of-states diagrams is to some extent artificial since these contributions produce similar terms, which partially cancel each other. In the diffusive limit, our results fully coincide with recent calculations in the Keldysh technique. In the ballistic limit near the transition, we demonstrate the absence of a divergent term $(T\tau)^2$ attributed previously to the density-of-states contribution. In the ballistic limit far above the transition, the temperature-dependent part of the conductivity correction is shown to scale roughly as $T\tau$.
Molecular Clouds in the Supergiant Shell LMC 4: Evidence for Triggered Cluster Formation

We have completed fully sampled observations of CO (J = 1-0) toward the supergiant shell (SGS) LMC 4 at a linear resolution of 40 pc with NANTEN. The result is the discovery of 18 clumpy CO clouds, 17 of which well delineate the SGS traced by Hα and H I. The remaining one cloud inside the SGS exhibits a cometary shape with an H I tail heading toward the center of the SGS. A comparison between the CO clouds and the young stars, including H II regions and stellar clusters, indicates that all the associated young stars are on the side of the clouds facing toward the center of the SGS. The typical separation between the cloud peaks and young stars is ~40-100 pc. These facts strongly suggest that star formation has been triggered by the expanding shell that is driven by OB stars, indicating the important role of SGSs in cluster formation in the LMC.
Boundary susceptibility in the open XXZ-chain

In the first part we calculate the boundary susceptibility ? B in the open XXZ-chain at zero temperature and arbitrary magnetic field h by the Bethe ansatz. We present analytical results for the leading terms when |h| ? , where ? is a known scale, and a numerical solution for the entire range of fields. In the second part we calculate susceptibility profiles near the boundary at finite temperature T numerically by using the density-matrix renormalization group for transfer matrices and analytically for T 1 by field theoretical methods. Finally, we compare ? B at finite temperature with a low-temperature asymptotics which we obtain by combining our Bethe ansatz result with recent predictions from bosonization.
Continuum and Spectral Line Radiation from a Random Clumpy Medium

We present a formalism for continuum and line emission from random clumpy media together with its application to problems of current interest, including CO spectral lines from ensembles of clouds and radio emission from H ii regions, supernovae, and star-forming regions. For line emission, we find that the effects of clump opacity on observed line ratios can be indistinguishable from variations of intrinsic line strengths, adding to the difficulties in determining abundances from line observations. Our formalism is applicable to arbitrary distributions of cloud properties, provided the cloud volume filling factor is small; numerical simulations show it to hold up to filling factors of ∼10%. We show that irrespective of the complexity of the cloud ensemble, the radiative effect of clumpiness can be parameterized at each frequency by a single multiplicative correction to the overall optical depth; this multiplier is derived from appropriate averaging over individual cloud properties. Our main finding is that cloud shapes have only a negligible effect on radiation propagation in clumpy media; the results of calculations employing point-like clouds are practically indistinguishable from those for finite-sized clouds with arbitrary geometrical shapes.