Miracle-dz/UniFAR-FTUs huggingface dataset:
Evidence for dispersing 1D Majorana channels in an iron-based superconductor

A possible propagating Majorana Majorana states in solid-state systems may one day form a basis for topological quantum computing. Most of the candidates identified so far have been Majorana bound states, but theorists have predicted that propagating Majorana states may exist as well. Wang et al. looked for such a state on the surface of the material FeSe0.45Te0. 55 (see the Perspective by Tewari and Stanescu). Using scanning tunneling spectroscopy, the researchers measured a flat, bias-independent density of states along a particular type of domain wall, which was consistent with a theoretical prediction for a propagating Majorana state in this material. Although topologically trivial origins of this finding are difficult to completely rule out, the work is likely to stimulate interest in iron-based superconductors as hosts of Majorana states. Science, this issue p. 104; see also p. 23 Scanning tunneling spectroscopy suggests a propagating Majorana state along a domain wall on the surface of FeSe0.45Te0. 55. The possible realization of Majorana fermions as quasiparticle excitations in condensed-matter physics has created much excitement. Most studies have focused on Majorana bound states; however, propagating Majorana states with linear dispersion have also been predicted. Here, we report scanning tunneling spectroscopic measurements of crystalline domain walls (DWs) in FeSe0.45Te0. 55. We located DWs across which the lattice structure shifts by half a unit cell. These DWs have a finite, flat density of states inside the superconducting gap, which is a hallmark of linearly dispersing modes in one dimension. This signature is absent in DWs in the related superconductor, FeSe, which is not in the topological phase. Our combined data are consistent with the observation of dispersing Majorana states at a π-phase shift DW in a proximitized topological material.
Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering

We perform an ensemble of N-body simulations with 20483 particles for 101 flat wCDM cosmological models sampled based on a maximin distance sliced Latin hypercube design. By using the halo catalogs extracted at multiple redshifts in the range of z = [0,1.48], we develop Dark Emulator, which enables fast and accurate computations of the halo mass function, halo–matter cross-correlation, and halo autocorrelation as a function of halo masses, redshift, separations, and cosmological models based on principal component analysis and Gaussian process regression for the large-dimensional input and output data vector. We assess the performance of the emulator using a validation set of N-body simulations that are not used in training the emulator. We show that, for typical halos hosting CMASS galaxies in the Sloan Digital Sky Survey, the emulator predicts the halo–matter cross-correlation, relevant for galaxy–galaxy weak lensing, with an accuracy better than 2% and the halo autocorrelation, relevant for galaxy clustering correlation, with an accuracy better than 4%. We give several demonstrations of the emulator. It can be used to study properties of halo mass density profiles such as the concentration–mass relation and splashback radius for different cosmologies. The emulator outputs can be combined with an analytical prescription of halo–galaxy connection, such as the halo occupation distribution at the equation level, instead of using the mock catalogs to make accurate predictions of galaxy clustering statistics, such as galaxy–galaxy weak lensing and the projected correlation function for any model within the wCDM cosmologies, in a few CPU seconds.
Dynamics of a droplet under the influence of an alternating electric field

We investigate the electrohydrodynamics of an initially spherical droplet in a leaky dielectric medium under the influence of an external AC electric field by conducting axisymmetric numerical simulations using a charge-conservative volume-of-fluid based finite volume flow solver. The droplet and the surrounding medium are assumed to have the same density and the same viscosity. The experimental study of torza1971 reported that along the zero circulation line (i.e. when electrical conductivity ratio, K_r is equal to the permittivity ratio, S), the mean deformation of a droplet in an applied AC electric field, E_AC (t) is equal to the steady state deformation in a DC field, E_DC equals to the root-mean-square of E_AC (t). However, in two-dimensional simulations, it is observed that the droplet deformation behaviours are similar under both AC and the equivalent DC electric fields even for the values of (S,K_r) away from the zero circulation line. This motivates us to revisit this problem by performing axisymmetric simulations. The main findings of our study are (i) for K_r le S, the droplet deformation shows strikingly different behaviour in case of an AC and the equivalent DC fields, (ii) unlike the previous numerical studies, the results obtained from our axisymmetric simulations are consistent with the experimental investigation of torza1971, and (iii) the parametric study conducted for a wide range of parameters.
Teichmueller flow and Weil-Petersson flow

For a non-exceptional oriented surface S let Q(S) be the moduli space of area one quadratic differentials. We show that there is a Borel subset E of Q(S) which is invariant under the Teichmueller flow F^t and of full measure for every invariant Borel probability measure, and there is a measurable conjugacy of the restriction of F^t to E into the Weil-Petersson flow. This conjugacy induces a continuous injection H of the space of invariant Borel probability measures for F^t into the space of invariant Borel probability measures for the Weil-Petersson flow. The map H is not surjective, but its image contains the Lebesgue Liouville measure.
Cosmological Perturbations Through a Simple Bounce

We present a study of a simple scalar field model that yields non‐singular cosmological solutions. We study both the qualitative dynamics of the homogeneous and isotropic background and the evolution of inhomogeneous linear perturbations. We calculate the spectrum of perturbations generated on super‐Hubble scales during the collapse phase from initial vacuum fluctuations on small scales and then evolve these numerically through the bounce. We show that the comoving curvature perturbation calculated during the collapse phase provides a good estimate of the resulting large scale adiabatic perturbation in the expanding phase while the Bardeen metric potential is dominated by what becomes a decaying mode after the bounce. We show that a power‐law collapse phase with scale factor proportional to (−t)2/3 can yield a scale‐invariant spectrum of adiabatic scalar perturbations in the expanding phase, but the amplitude of tensor perturbations places important constraints on the allowed initial conditions.
Simulations of X-ray clusters

We present simulations of the formation and evolution of galaxy clusters in the Cold Dark Matter cosmogony. Clusters with a wide range of mass were selected from previous N-body models, and were resimulated at higher resolution using a combined N-body/Smooth Particle Hydrodynamics code. The effects of radiative cooling on the gas are neglected. While many present-day clusters are predicted to be undergoing mergers, the density profiles of those that are approximately in equilibrium are all very similar, both for the gas and for the dark matter. These profiles show no sign of a uniform density core and steepen gradually from the centre outwards. The standard $\beta$-model is a reasonable fit over most of the radius range observable in real clusters. However, the value obtained for the slope parameter $\beta_f$ increases with the outermost radius of the fit. Temperature profiles of different simulated clusters are also similar. Typically the temperature is almost uniform in the regions which emit most of the X-ray flux but drops at larger radii. The gas temperature and dark matter velocity dispersion in equilibrium clusters give values of $\beta_T\equiv \mu m_p\sigma_{DM}^2/kT$ which are consistent with unity provided an X-ray emission-weighted temperature is used. Larger values of $\beta_T$ are found in merging objects where there is a transient boost in the velocity dispersion of the system. Thus $\beta_T >1$ may be an observational indicator of merging in real clusters. The similar structure of clusters of differing mass results in scaling relations between the X-ray and dynamical properties of clusters identified at
Linear Models of Supersymmetric D-Branes

We construct a class of supersymmetric boundary interactions in N=2 field theories on the half-space, which depend on parameters that are not at all renormalized or not renormalized in perturbation theory beyond one-loop. This can be used to study D-branes wrapped on a certain class of Lagrangian submanifolds as well as holomorphic cycles. The construction of holomorphic D-branes is in close relationship with the background independent open string field theory approach to brane/anti-brane systems. As an application, mirror pairs of Lagrangian and holomorphic D-branes are identified. The mirror pairs are studied by twisting to open topological field theories.
Accuracy of DIF Estimates and Power in Unbalanced Designs Using the Mantel–Haenszel DIF Detection Procedure

This study examined how much improvement was attainable with respect to accuracy of differential item functioning (DIF) measures and DIF detection rates in the Mantel–Haenszel procedure when employing focal and reference groups with notably unbalanced sample sizes where the focal group has a fixed small sample which does not satisfy the minimum DIF sample size requirement specified by the testing programs, while the reference group sample size far exceeds the minimum requirement. Results showed equivalent or better results with such unbalanced but large samples than with some of the currently used minimum DIF sample size conditions. DIF investigation, therefore, does not necessarily need to cease when the focal group does not meet the minimum sample size requirement. Some analytic explanations and guidelines for DIF investigations with unbalanced sample sizes are also provided.
Discovery of an Afterglow Extension of the Prompt Phase of Two Gamma-Ray Bursts Observed by Swift

BAT and XRT observations of two recent well-covered GRBs observed by Swift, GRB 050315 and GRB 050319, clearly show a prompt component joining the onset of the afterglow emission. By fitting a power-law form to the γ-ray spectrum, we extrapolate the time-dependent fluxes measured by BAT, in the energy band 15-350 keV, into the spectral regime observed by XRT, 0.2-10 keV, and examine the functional form of the rate of decay of the two light curves. We find that the BAT and XRT light curves merge to form a unified curve. There is a period of steep decay up to ~300 s, followed by a flatter decay. The duration of the steep decay, ~100 s in the source frame after correcting for cosmological time dilation, agrees roughly with a theoretical estimate for the deceleration time of the relativistic ejecta as it interacts with circumstellar material. For GRB 050315, the steep decay can be characterized by an exponential form, where the e-folding decay time τe ≃ 24 ± 2 s (BAT), and τe ≃ 35 ± 2 s (XRT). For GRB 050319, a power-law decay -d ln f/d ln t = n, where n ≃ 3 provides a reasonable fit. The early-time X-ray fluxes are consistent with representing the lower energy tail of the prompt emission and provide our first quantitative measure of the decay of the prompt γ-ray emission over a large dynamic range in flux. The initial steep decay is expected, due to the delayed high-latitude photons from a curved shell of relativistic plasma illuminated only for a short interval. The overall conclusion is that the prompt phase of GRBs remains observable for hundreds of seconds longer than previously thought.
Synergy of Stochastic and Systematic Energization of Plasmas during Turbulent Reconnection

The important characteristic of turbulent reconnection is that it combines large-scale magnetic disturbances with randomly distributed unstable current sheets (UCSs). Many well-known nonlinear MHD structures (strong turbulence, current sheet(s), shock(s)) lead asymptotically to the state of turbulent reconnection. We analyze in this article, for the first time, the energization of electrons and ions in a large-scale environment that combines large-amplitude disturbances propagating with sub-Alfvénic speed with UCSs. The magnetic disturbances interact stochastically (second-order Fermi) with the charged particles and play a crucial role in the heating of the particles, while the UCSs interact systematically (first-order Fermi) and play a crucial role in the formation of the high-energy tail. The synergy of stochastic and systematic acceleration provided by the mixture of magnetic disturbances and UCSs influences the energetics of the thermal and nonthermal particles, the power-law index, and the length of time the particles remain inside the energy release volume. We show that this synergy can explain the observed very fast and impulsive particle acceleration and the slightly delayed formation of a superhot particle population.
Reconstructing projected matter density power spectrum from cosmic microwave background

Gravitational lensing distorts the cosmic microwave background (CMB) anisotropies and imprints a characteristic pattern onto it. The distortions depend on the projected matter density between today and redshift $z \sim 1100$. In this paper we develop a method for a direct reconstruction of the projected matter density from the CMB anisotropies. This reconstruction is obtained by averaging over quadratic combinations of the derivatives of CMB field. We test the method using simulations and show that it can successfully recover projected density profile of a cluster of galaxies if there are measurable anisotropies on scales smaller than the characteristic cluster size. In the absence of sufficient small scale power the reconstructed maps have low signal to noise on individual structures, but can give a positive detection of the power spectrum or when cross correlated with other maps of large scale structure. We develop an analytic method to reconstruct the power spectrum including the effects of noise and beam smoothing. Tests with Monte Carlo simulations show that we can recover the input power spectrum both on large and small scales, provided that we use maps with sufficiently low noise and high angular resolution.
Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg1/3Ta2/3O3

The behavior of longitudinal acoustic (LA) and transverse acoustic (TA) phonons in a cubic relaxor PbMg1/3Ta2/3O3 (PMT) ferroelectric has been investigated by Brillouin light scattering. Analysis of the temperature dependences of phonon velocity in the temperature range from 50 to 870 K has revealed anomalies in the vicinity of the Burns temperature (TB≈570 K) for LA phonons and a wide frequency-dependent minimum of the velocities of LA and TA phonons in the same temperature region as the dielectric response anomaly. Using experimental data, temperature dependences of the C11 and C44 elastic constants have been calculated. The elastic constants have been found to be frequency-independent in the gigahertz range. The results obtained are discussed in the framework of modern ideas on the crystalline lattice dynamics of relaxor ferroelectrics.
Spatially resolved stellar mass buildup and quenching in massive disk galaxies over the last 10 Gyr revealed with spatially resolved SED fitting

Abstract Despite decreasing cosmic star formation rate density over the last 10 Gyr, the stellar mass (M*) buildups in galaxies were still progressing during this epoch. About 50% of the current M* density in the universe was built over the last ∼8.7 Gyr. In this research, we investigated the stellar mass buildup and quenching of spatially resolved regions within massive disk galaxies over the last 10 Gyr. We apply the spectral energy distribution (SED) fitting method to SEDs of sub-galactic regions in galaxies to derive the spatially resolved distributions of SFR and M* in the galaxies. This namely pixel-to-pixel SED fitting method is applied to massive disk galaxies at 0.01 < z < 0.02 and 0.8 < z < 1.8. We found that massive disk galaxies tend to build their M* and quench their star formation progressively from the central region to the outskirts, i.e. inside-out stellar mass buildup and quenching.
Theory of the kagome lattice Ising antiferromagnet in weak transverse fields

We study the quantum Ising antiferromagnet on the Kagome lattice, with weak transverse field dynamics and other local perturbations. We analytically demonstrate the possibility of a disordered zero-temperature phase that is smoothly connected to the phase at strong transverse fields. This is done by means of an appropriate mapping to a compact U(1) gauge theory on the honeycomb lattice that is coupled to a charge-1 matter field. Our results are consistent with existing Monte-Carlo calculations. The differences with other commonly studied lattices (in which such disordered phases do not obtain at weak transverse fields) is explained. Ordered phases are also shown to be possible in principle in the weak transverse field limit, and are briefly studied.
State independent contextuality advances one-way communication

Although ‘quantum contextuality’ is one of the most fundamental non-classical feature, its generic role in information processing and computation is an open quest. In this article, we present a family of distributed computing tasks pertaining to every logical proof of Kochen–Specker (KS) contextuality in two different one-way communication scenarios: (I) communication of bounded dimensional system, (II) communication of unbounded dimensional system while keeping certain information oblivious, namely, oblivious communication (OC). As the later remains largely unexplored, we introduce a general framework for OC tasks and provide a methodology for obtaining an upper bound on the success of OC tasks in classical communication. We show that quantum communication comprised of every KS set of vectors outperforms classical communication and perfectly accomplish the task in both the aforementioned scenarios. We explicitly discuss the communication tasks pertaining to the simplest state independent contextuality sets of dimension three and four. Our results establish an operational significance to single system contextuality and open up the possibility of semi-device independent quantum information processing based on that. Alongside, we identify any advantage in OC tasks as a witness of preparation contextuality.
CMB lensing bispectrum: Assessing analytical predictions against full-sky lensing simulations

Cosmic microwave background (CMB) lensing is an integrated effect whose kernel is greater than half the peak value in the range $1<z<5$. Measuring this effect offers a powerful tool to probe the large-scale structure of the Universe at high redshifts. With the increasing precision of ongoing CMB surveys, other statistics than the lensing power spectrum, in particular the lensing bi-spectrum, will be measured at high statistical significance. This will provide ways to improve the constraints on cosmological models and lift degeneracies. Following on an earlier paper, we test analytical predictions of the CMB lensing bi-spectrum against full-sky lensing simulations, and discuss their validity and limitation in detail. The tree-level prediction of perturbation theory agrees with the simulation only up to $\ell\sim 200$, but the one-loop order allows capturing the simulation results up to $\ell\sim 600$. We also show that analytical predictions based on fitting formulas for the matter bi-spectrum agree reasonably well with simulation results, although the precision of the agreement depends on the configurations and scales considered. For instance, the agreement is at the $10\%$-level for the equilateral configuration at multipoles up to $\ell\sim2000$, but the difference in the squeezed limit raises to more than a factor of two at $\ell\sim2000$. This discrepancy appears to come from limitations in the fitting formula of the matter bi-spectrum. We also find that the analytical prediction for the post-Born correction to the bi-spectrum is in good agreement with the simulation. We conclude by discussing the bi-spectrum prediction in some theories of modified gravity.
One-loop corrections to omega photoproduction near threshold

One-loop corrections to $\omega$ photoproduction near threshold have been investigated by using the approximation that all relevant transition amplitudes are calculated from the tree diagrams of effective Lagrangians. With the parameters constrained by the data of $\gamma N \to \pi N$, $\gamma N \to \rho N$, and $\pi N \to \omega N$ reactions, it is found that the one-loop effects due to the intermediate $\pi N$ and $\rho N$ states can significantly change the differential cross sections and spin observables. The results from this exploratory investigation suggest strongly that the coupled-channel effects should be taken into account in extracting reliable resonance parameters from the data of vector meson photoproduction in the resonance region.
A Spectroscopic and Photometric Survey of Stars in the Field of L1457: A New Distance Determination

We present a spectroscopic and photometric survey of a sample of field stars in the region of the molecular cloud L1457. High-quality coudé feed spectra, together with five-band photometry in the Sloan Digital Sky Survey system and near-infrared archival data from the Two Micron All Sky Survey, are used to derive color excesses and distances for the stars. Based on these data, a new distance estimate of 360 ± 30 pc is derived for the cloud, supporting recent results by K. L. Luhman. The data further indicate that the north-south velocity gradient seen in the millimeter-wave CO data is mirrored in a distance gradient, with the northern part of the cloud being closer to us. A second, less opaque, layer of extinction is detected at ∼80 pc. This distance is consistent with the earlier distance estimates to the cloud, based on Na I absorption. We identify this layer with the wall of the hot Local Bubble. Hence, the dense cloud is not, as previously thought, associated with the Local Bubble.
Magnetic Properties of (Co1-xMnx)2P Compounds

Measurements of the magnetization, magnetic susceptibility and NMR have been made for (Co 1- x Mn x ) 2 P single crystal compounds. The compounds with orthorhombic structure are ferromagnetic for 0.06< x <0.63, ferromagnetic at high temperatures and screw antiferromagnetic at low temperatures for 0.63 ≤ x ≤0.73 and antiferromagnetic for 0.73 ≤ x ≤0.80. The magnetic moments of Mn I and Mn II are expected to have about 1 and 3 µ B , respectively, from the measurement of NMR. The magnetocrystalline anisotropy constants K 1 and K 2 are both negative and their absolute values take maxima at x =0.5. The Curie temperatures and saturation magnetic moments for x ≤0.5 compounds are briefly discussed with the exchange interaction and the local environment of Mn II site.