Miracle-dz/UniFAR-FTUs huggingface dataset:
Chandra Observations of 12 Luminous Red Quasars

We present results of a study of 12 dust-reddened quasars with 0.4 < z < 2.21 and reddenings in the range 0.15 < E(B - V) < 1.7. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities toward them, and hence obtained the gas : dust ratios in the material obscuring the quasar. We detect all but one of the red quasars in the X-rays. Even though there is no obvious correlation between the X-ray-determined column densities of our sources and their optical color or reddening, all of the sources show absorbed X-ray spectra. When we correct the luminosity for absorption, they can be placed among luminous quasars; therefore, our objects belong to the group of high-luminosity analogs of the sources contributing to the X-ray background seen in deep X-ray observations. Such sources are also found in serendipitous shallow X-ray surveys. There is a hint that the mean spectral slope of the red quasar is higher than that of normal, unobscured quasars, which could be an indication for higher accretion rates and/or an evolutionary effect. We investigate the number density of these sources compared to type 2 AGNs based on the X-ray background and estimate how many moderate-luminosity red quasars may be found in deep X-ray fields.
A wave model for the aurora

A wave-particle interaction model is proposed for the electron acceleration that leads to discrete aurora. Measurements of accelerated electrons are used to deduce the wave spectrum and the nature of the waves responsible for acceleration. The waves are identified as lower-hybrid waves. Generation of the waves by various free energy sources is considered and the wave energy required to account for the aurora is calculated and compared with observations.
Detection of non-homologous end joining events:

RNA polymerase III (Pol III) promoters express short non-coding RNAs and have been adopted for expression of microRNA, interfering RNA, and CRISPR single guide RNA (sgRNA). Vectors incorporating H1 and U6 Pol III promoters are being applied for therapeutic genome editing, including multiplexed CRISPR/Cas9 effects. We report a nucleosome-depleted, minimal U6 promoter, which when embedded within lentiviral long terminal repeat (LTR) regions, supports high level transcriptional activity. Furthermore, duplex minimal H1 & U6 promoters transcribed dual sgRNAs for simultaneous disruption of T cell receptor (TCR) and human leukocyte antigen (HLA) molecules, supporting efficient generation of ‘universal’ CAR T cells.
The cosmological dependence of cluster density profiles

We use N-body simulations to study the shape of mean cluster density and velocity profiles in the nonlinear regime formed via gravitational instability. The dependence of the final structure on both cosmology and initial density field is examined, using a grid of cosmologies and scale-free initial power spectra P(k) varies as k(exp n). Einstein-de Sitter, open (Omega(sub 0) = 0.2 and 0.1) and flat, low density (Omega(sub 0) = 0.2 lambda(sub 0) = 0.8) models are examined, with initial spectral indices n = -2, -1 and 0. For each model, we stack clusters in an appropriately scaled manner to define an average density profile in the nonlinear regime. The profiles are well fit by a power law rho(r) varies as r(exp -alpha) for radii whereat the local density contrast is between 100 and 3000. This covers 99% of the cluster volume. We find a clear trend toward steeper slopes (larger alphas) with both increasing n and decreasing Omega(sub 0). The Omega(sub 0) dependence is partially masked by the n dependence; there is degeneracy in the values of alpha between the Einstein-de Sitter and flat, low-density cosmologies. However, the profile slopes in the open models are consistently higher than the Omega = 1 values for the range of n examined. Cluster density profiles are thus potentially useful cosmological diagnostics. We find no evidence for a constant density core in any of the models, although the density profiles do tend to flatten at small radii. Much of the flattening is due to the force softening required by the simulations. An attempt is made to recover the unsoftened profiles assuming angular momentum invariance. The recovered profiles in Einstein-de Sitter cosmologies are consistent with a pure power law up to the highest density contrasts (10(exp 6)) accessible with our resolution. The low-density models show significant deviation from a power law above density contrasts approximately 10(exp 5). We interpret this curvature as reflecting the non-scale-invariant nature of the background cosmology in these models. These results are at the limit of our resolution and so should be tested in the future using simulations with larger numbers of particles. Such simulations will also provide insight on the broader problem of understanding, in a statistical sense, the full phase space structure of collapsed, cosmological halos.
Hints against the cold and collisionless nature of dark matter from the galaxy velocity function

The observed number of dwarf galaxies as a function of rotation velocity is significantly smaller than predicted by the standard model of cosmology. This discrepancy cannot be simply solved by assuming strong baryonic feedback processes, since they would violate the observed relation between maximum circular velocity (vmax) and baryon mass of galaxies. A speculative but tantalizing possibility is that the mismatch between observation and theory points towards the existence of non-cold or non-collisionless dark matter (DM). In this paper, we investigate the effects of warm (WDM), mixed (MDM, i.e. warm plus cold), and self-interacting DM (SIDM) scenarios on the abundance of dwarf galaxies and the relation between observed H i line width and maximum circular velocity. Both effects have the potential to alleviate the apparent mismatch between the observed and theoretical abundance of galaxies as a function of vmax. For the case of WDM and MDM, we show that the discrepancy disappears, even for lukewarm models that evade stringent bounds from the Lyman-α forest. SIDM scenarios can also provide a solution as long as they lead to extended (≳1.5 kpc) DM cores in the density profiles of dwarf galaxies. Only models with velocity-dependent cross-sections can yield such cores without violating other observational constraints at larger scales.
Forced oscillations of a bubble in a liquid

Experiments are described in which a periodic sound field is used to force drive the bubble and a hydrophone detects the sound radiated from the oscillating bubble. Results are given for single static bubbles, rising bubbles and paired bubbles. The bubble shape, as well as volume, is found to be important in determining the resonant frequency.
Effect of P wave interaction in He-6 and Li-6 photoabsorption

The total photoabsorption cross sections of six-body nuclei are calculated including complete final state interaction via the Lorentz Integral Transform method. The effect of nucleon-nucleon central P-wave forces is investigated. Comparing to results with central potentials containg S-wave forces only one finds considerably more strength in the low-energy cross sections and a rather strong improvement in comparison with experimental data, in particular for 6Li.
Measuring the Kondo effect in the Aharonov-Bohm interferometer

The conductance $\mathcal{G}$ of an Aharonov-Bohm interferometer (ABI), with a strongly correlated quantum dot on one arm, is expressed in terms of the dot Green function, ${G}_{dd}$, the magnetic flux $\ensuremath{\phi}$ and the noninteracting parameters of the ABI ${{J}_{\ensuremath{\mu}\ensuremath{\nu}}}$. At $T=0$, Fermi liquid theory yields the exact $\ensuremath{\phi}$ dependence of $\mathcal{G}$. We show that one can extract ${G}_{dd}$ from the observed $\mathcal{G}(\ensuremath{\phi})$, for both closed and open ABI's. In the latter case, the phase shift $\ensuremath{\beta}$ deduced from $\mathcal{G}\ensuremath{\approx}A+B\phantom{\rule{0.2em}{0ex}}\mathrm{cos}(\ensuremath{\phi}+\ensuremath{\beta})$ depends strongly on the ${{J}_{\ensuremath{\mu}\ensuremath{\nu}}}$'s, and usually $\ensuremath{\beta}\ensuremath{\ne}\ensuremath{\pi}∕2$. The ${{J}_{\ensuremath{\mu}\ensuremath{\nu}}}$'s may also reduce the Kondo temperature.
Evolution of fluctuation in relativistic heavy-ion collisions

We have studied the time evolution of the fluctuations in the net baryon number for different initial conditions and space-time evolution scenarios. We observe that the fluctuations at the freeze-out depend crucially on the equation of state (EOS) of the system and for realistic EOS the initial fluctuation is substantially dissipated at the freeze-out stage. At superproton synchrotron energies the fluctuations in net baryon number at the freeze-out stage for quark-gluon plasma and hadronic initial state is close to the Poissonian noise for ideal as well as for EOS obtained by including heavier hadronic degrees of freedom. For EOS obtained from the parametrization of lattice QCD results the fluctuation is larger than Poissonian noise. It is also observed that at relativistic heavy-ion collider energies the fluctuations at the freeze-out point deviates from the Poissonian noise for ideal as well as realistic equation of state, indicating presence of dynamical fluctuations.
Increased performance of Matsubara space calculations: A case study within Eliashberg theory

We present a method to considerably improve the numerical performance for solving Eliashberg-type coupled equations on the imaginary axis. Instead of the standard practice of introducing a hard numerical cutoff for treating the infinite summations involved, our scheme allows for the efficient calculation of such sums extended formally up to infinity. The method is first benchmarked with isotropic Migdal-Eliashberg theory calculations and subsequently applied to the solution of the full-bandwidth, multiband and anisotropic equations focusing on the FeSe/SrTiO$_3$ interface as a case study. Compared to the standard procedure, we reach similarly well converged results with less than one fifth of the number of frequencies for the anisotropic case, while for the isotropic set of equations we spare approximately ninety percent of the complexity. Since our proposed approximations are very general, our numerical scheme opens the possibility of studying the superconducting properties of a wide range of materials at ultra-low temperatures.
Invariant theory, generalized Casimir operators, and tensor product decompositions of U(N)

One of the central problems in the representation theory of compact groups concerns multiplicity, wherein an irreducible representation occurs more than once in the decomposition of the n-fold tensor product of irreducible representations. The problem is that there are no operators arising from the group itself whose eigenvalues can be used to label the equivalent representations occurring in the decomposition. In this paper we use invariant theory along with so-called generalized Casimir operators to show how to resolve the multiplicity problem for the U(N) groups. The starting point is to augment the n-fold tensor product space with the contragredient representation of interest and construct a subspace of U(N) invariants. The setting for this construction is a polynomial space embedded in a Fock space of complex variables which carries all the irreducible representations of U(N) (or GLN ℂ). The dimension of the invariant subspace is equal to the multiplicity occurring in the tensor product decomposition. Generalized Casimir operators are operators from the universal enveloping algebra of outer product U(N) groups that commute with the diagonal U(N) action and whose eigenvalues can be used to label the multiplicity. Using the notion of dual representations we show how to rewrite the generalized Casimir operators and prove that they act invariantly on the invariant subspace. A complete set of commuting generalized Casimir operators can therefore be used to construct eigenvectors that form an orthonormal basis in the invariant subspace. Different sets of generalized commuting Casimir operators generate different orthonormal bases in the invariant subspace; the overlaps between the eigenvectors of different commuting sets of generalized Casimir operators are called invariant coefficients. We show that Racah coefficients are special cases of invariant coefficients in which the generalized Casimir operators have been chosen with respect to a definite coupling scheme in the tensor product. The paper concludes with an example of the threefold tensor product of the eight-dimensional irreducible representation of U(3) in which the multiplicity of the chosen irreducible representation is 6. Eigenvectors in the six-dimensional invariant subspace are computed for different sets of generalized Casimir operators and invariant coefficients, including Racah coefficients.
Energy paths in edge waves

In this paper the energy streamlines, energy paths, and energy streak lines in a steady or unsteady inhomogeneous acoustic field next to an unstable oscillating boundary, such as a vortex sheet or shear layer, are determined. The theory in the paper applies also to an evanescent wave produced by total internal reflection, and to any other type of edge wave, e.g. a coastally or topographically trapped wave in geophysical fluid dynamics. The idea of the paper is that energy velocity, i.e. energy flux divided by energy density, is defined at every point in space and time, not merely when averaged over a cycle. Integration of the ordinary differential equation for energy velocity as a function of position and time gives the energy paths. These paths are calculated explicitly, and are found to have starting and finishing directions very different from those of cycle-averaged paths. The paper discusses the physical significance of averaged and non-averaged energy paths, especially in relation to causality. Many energy paths have cusps, at which the energy velocity is instantaneously zero. The domain of influence of an arbitrary point on the boundary of a steady acoustic edge wave is shown to lie within 45° of a certain direction, in agreement with a known result on shear-layer instability in compressible flow. The results are consistent with flow visualization photographs of near-field jet noise. The method of the paper determines domains of influence and causality in any wave problem with an explicit solution, for example as represented by a Fourier integral.
Spectroscopic modelling of four neutron star low-mass X-ray binaries usingcloudy

Low-mass X-ray binaries (LMXBs) have a wide range of X-ray properties which can be utilised to reveal many physical conditions of the associated accretion discs. We use the spectral synthesis code CLOUDY to perform a detailed modelling of neutron star LMXBs GX 13+1, MXB 1659--298, 4U 1323--62 and XB 1916--053; and characterise the underlying physical conditions, such as density, radiation field, metallicity, wind velocity, etc. For this purpose we model highly ionised spectra of Fe, Ca, S, Si, Mg, Al in the soft X-ray band, and compare the predicted line flux ratios with the observed values. We also find that the strength and profile of these spectral lines get modified in the presence of magnetic field in the accretion disc. Using this, we estimate an upper limit of the existing magnetic field to be about a few hundred to a few thousand G in the accretion discs of these four LMXBs.
Hadron scattering in an asymmetric box

We propose to study hadron-hadron scattering using lattice QCD in an asymmetric box which allows one to access more non-degenerate low-momentum modes for a given volume. The conventional Luscher's formula applicable in a symmetric box is modified accordingly. To illustrate the feasibility of this approach, pion-pion elastic scattering phase shifts in the I = 2, J = 0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. After the chiral and continuum extrapolation, we find that our quenched results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. Agreement is also found when compared with previous theoretical results from lattice and other means. Moreover, with the usage of asymmetric volume, we are able to compute the scattering phases in the low-momentum range (pion three momentum less than about 350MeV in the center of mass frame) for over a dozen values of the pion three-momenta, much more than using the conventional symmetric box with comparable volume.
A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: Implications for H0

Strong gravitational lensing provides an independent measurement of the Hubble parameter (H0). One remaining systematic is a bias from the additional mass due to a galaxy group at the lens redshift or along the sightline. We quantify this bias for more than 20 strong lenses that have well-sampled sightline mass distributions, focusing on the convergence κ and shear γ. In 23% of these fields, a lens group contributes ≥1% convergence bias; in 57%, there is a similarly significant line-of-sight group. For the nine time-delay lens systems, H0 is overestimated by % on average when groups are ignored. In 67% of fields with total , line-of-sight groups contribute more convergence than do lens groups, indicating that the lens group is not the only important mass. Lens environment affects the ratio of four (quad) to two (double) image systems; all seven quads have lens groups while only 3 of 10 doubles do, and the highest convergences due to lens groups are in quads. We calibrate the γ–κ relation: with an rms scatter of 0.34 dex. Although shear can be measured directly from lensed images, unlike convergence, it can be a poor predictor of convergence; for 19% of our fields, κ is . Thus, accurate cosmology using strong gravitational lenses requires precise measurement and correction for all significant structures in each lens field.
Out-of-time-ordered correlators in short-range and long-range hard-core boson models and in the Luttinger-liquid model

We study out-of-time-ordered correlators (OTOCs) in hard-core boson models with short-range and long-range hopping and compare the results to the OTOCs in the Luttinger-liquid model. For density-density correlations, a related expectation value of the squared commutator starts at zero and decays back to zero after the passage of the wavefront in all three models, while the wavefront broadens as t^(1/3) in the short-range model and shows no broadening in the long-range model and the Luttinger-liquid model. For the boson creation operator, the corresponding commutator function shows saturation inside the light cone in all three models, with similar wavefront behavior as in the density-density commutator function, despite the presence of a nonlocal string in terms of Jordan-Wigner fermions. For the long-range model and the Luttinger-liquid model, the commutator function decays as a power law outside the light cone in the long-time regime when following different fixed-velocity rays. In all cases, the OTOCs approach their long-time values in a power-law fashion, with different exponents for different observables and short-range versus long-range cases. Our long-range model appears to capture exponents in the Luttinger-liquid model (which are found to be independent of the Luttinger parameter in the model). This conclusion also comes to bear on the OTOC calculations in conformal field theories, which we propose correspond to long-ranged models.
Multifragmentation reactions and properties of stellar matter at subnuclear densities

We point out the similarity of thermodynamic conditions reached in nuclear multifragmentation and in supernova explosions. We show that a statistical approach previously applied for nuclear multifragmentation reactions can also be used to describe the electroneutral stellar matter. Then properties of hot unstable nuclei extracted from the analysis of multifragmentation data can be used to determine a realistic nuclear composition of hot supernova matter.
Solutions to the tokamak circuit equations with force balance for a massless plasma

A computational model has been developed for time simulation of the interaction of a massless filamentary tokamak plasma with the vacuum vessel and external circuits. The non-linear circuit equations are solved in a way which allows the dynamical characteristics of the power supplies to be easily incorporated. This model is used to explore the relationship of plasma control programming, coil characteristics and power supply requirements.
Twisted Weil Algebras for the String Lie 2‐Algebra

In this article, we give a concise summary of L∞ ‐algebras viewed in terms of Chevalley–Eilenberg algebras, Weil algebras and invariant polynomials and their use in defining connections in higher gauge theory. Using this, we discuss the example of the string Lie 2‐algebra in both the skeletal and the loop model. In both cases, we show how to arrive at the twisted Weil algebras which were used in [1] to construct a non‐abelian self‐dual string soliton, see also [2–4].
Conformal symmetry and the nonlinear Schrödinger equation

We show that the width of the wave packet of a class of generalized nonlinear Schr\"odinger equations (NLSE) trapped in an arbitrary time-dependent harmonic well in any dimensions is universally determined by the same Hill's equation. This class of generalized NLSE is characterized by a dynamical O(2,1) symmetry in absence of the trap. As an application, we study the dynamical instabilities of the rotating as well as nonrotating Bose-Einstein condensates in one and two dimensions. We also show exact extended parametric resonance in a nonrelativistic Chern-Simons theory producing a gauged NLSE.
A Metal-poor Damped Lyα System at Redshift 6.4

We identify a strong Lyα damping wing profile in the spectrum of the quasar P183+05 at z = 6.4386. Given the detection of several narrow metal absorption lines at z = 6.40392, the most likely explanation for the absorption profile is that it is due to a damped Lyα system. However, in order to match the data a contribution of an intergalactic medium 5%–38% neutral or additional weaker absorbers near the quasar is also required. The absorption system presented here is the most distant damped Lyα system currently known. We estimate an H i column density of 1020.68±0.25 cm−2, metallicity [O/H] = −2.92 ± 0.32, and relative chemical abundances of a system consistent with a low-mass galaxy during the first Gyr of the universe. This object is among the most metal-poor damped Lyα systems known and, even though it is observed only ∼850 Myr after the big bang, its relative abundances do not show signatures of chemical enrichment by Population III stars.
Lattice theory of trapping reactions with mobile species

We present a stochastic lattice theory describing the kinetic behavior of trapping reactions A + B → B , in which both the A and B particles perform an independent stochastic motion on a regular hypercubic lattice. Upon an encounter of an A particle with any of the B particles, A is annihilated with a ﬁnite probability; ﬁnite reaction rate is taken into account by introducing a set of two-state random variables - ”gates”, imposed on each B particle, such that an open (closed) gate corresponds to a reactive (passive) state. We evaluate here a formal expression describing the time evolution of the A particle survival probability, which generalizes our previous results. We prove that for quite a general class of random motion of the species involved in the reaction process, for inﬁnite or ﬁnite number of traps, and for any time t , the A particle survival probability is always larger in case when A stays immobile, than in situations when it moves.