Miracle-dz/UniFAR-FTUs huggingface dataset:
Quasiparticles beyond the Fermi liquid and heavy fermion criticality

We give a self-consistent theory of the scale dependent effective mass enhancement m*/m of quasiparticles by 3D antiferromagnetic (AFM) spin fluctuations in the presence of disorder at an AFM quantum critical point. The coupling of fermionic and bosonic degrees of freedom in the critical regime is described in terms of a critical quasiparticle theory. Using the fact that even in the "non-Fermi liquid" regime the quasiparticle width does not exceed the quasiparticle energy, we adopt relations from Fermi liquid theory to determine the dependence of the spin fluctuation spectrum on m*/m, from which the self energy and hence m*/m may be calculated. The self-consistent equation for m*/m has a strong coupling solution provided the initial value is sufficiently large. We argue that in YbRh2Si2, quasi-2D Gaussian fluctuations existing over a wide range drive the system into the 3D strongly coupled fluctuation regime. We find critical exponents of the temperature dependence of the specific heat coefficient \gamma\propto T^{-1/4} and of the resistivity \rho(T)=\rho(0)+ A T^{3/4} in good agreement with experiments on YbRh2Si2 in the temperature range T < 0.3K.
Dipolar dynamos in stratified systems

Observations of low-mass stars reveal a variety of magnetic field topologies ranging from large-scale, axial dipoles to more complex magnetic fields. At the same time, three-dimensional spherical simulations of convectively driven dynamos reproduce a similar diversity, which is commonly obtained either with Boussinesq models or with more realistic models based on the anelastic approximation, which take into account the variation of the density with depth throughout the convection zone. Nevertheless , a conclusion from different anelastic studies is that dipolar solutions seem more difficult to obtain as soon as substantial stratifications are considered. In this paper, we aim at clarifying this point by investigating in more detail the influence of the density stratification on dipolar dynamos. To that end, we rely on a systematic parameter study that allows us to clearly follow the evolution of the stability domain of the dipolar branch as the density stratification is increased. The impact of the density stratification both on the dynamo onset and the dipole collapse is discussed and compared to previous Boussinesq results. Furthermore, our study indicates that the loss of the dipolar branch does not ensue from a specific modification of the dynamo mechanisms related to the background stratification, but could instead result from a bias as our observations naturally favour a certain domain in the parameter space characterized by moderate values of the Ekman number, owing to current computational limitations. Moreover, we also show that the critical magnetic Reynolds number of the dipolar branch is scarcely modified by the increase of the density stratification, which provides an important insight into the global understanding of the impact of the density stratification on the stability domain of the dipolar dynamo branch.
Self-gravitating systems of ideal gases in the 1PN approximation

We obtain the Maxwell-J\"uttner distribution function at first order in the post-Newtonian approximation within the framework of general relativity. Taking into account the aforesaid distribution function, we compute the particle four-flow and energy-momentum tensor. We focus on the search of static solutions for the gravitational potentials with spherical symmetry. In doing so, we obtain the density, pressure and gravitational potential energy profiles in terms of dimensionless radial coordinate by solving the aforesaid equations numerically. In particular, we find the parametric profile for the equation of state $p/\rho$ in terms of the dimensionless radial coordinate. Due to its physical relevance, we also find the galaxy rotation curves using the post-Newtonian approximation. We join two different kinds of static solutions in order to account for the linear regime near the center and the typical flatten behavior at large radii as well.
Magnetic shielding and exotic spin-dependent interactions

Author(s): Jackson Kimball, DF; Dudley, J; Li, Y; Thulasi, S; Pustelny, S; Budker, D; Zolotorev, M | Abstract: © 2016 American Physical Society. Experiments searching for exotic spin-dependent interactions typically employ magnetic shielding between the source of the exotic field and the interrogated spins. We explore the question of what effect magnetic shielding has on detectable signals induced by exotic fields. Our general conclusion is that for common experimental geometries and conditions, magnetic shields should not significantly reduce sensitivity to exotic spin-dependent interactions, especially when the technique of comagnetometry is used. However, exotic fields that couple to electron spin can induce magnetic fields in the interior of shields made of a soft ferromagnetic or ferrimagnetic material. This induced magnetic field must be taken into account in the interpretation of experiments searching for new spin-dependent interactions and raises the possibility of using a flux concentrator inside magnetic shields to amplify exotic spin-dependent signals.
The BaLROG project – I. Quantifying the influence of bars on the kinematics of nearby galaxies

We present the BaLROG (Bars in Low Redshift Optical Galaxies) sample of 16 morphologically distinct barred spirals to characterise observationally the influence of bars on nearby galaxies. Each galaxy is a mosaic of several pointings observed with the IFU spectrograph SAURON leading to a tenfold sharper spatial resolution (~100 pc) compared to ongoing IFU surveys. In this paper we focus on the kinematic properties. We calculate the bar strength Qb from classical torque analysis using 3.6 {\mu}m Spitzer (S4G) images, but also develop a new method based solely on the kinematics. A correlation between the two measurements is found and backed up by N-body simulations, verifying the measurement of Qb . We find that bar strengths from ionised gas kinematics are ~2.5 larger than those measured from stellar kinematics and that stronger bars have enhanced influence on inner kinematic features. We detect that stellar angular momentum "dips" at 0.2$\pm$0.1 bar lengths and half of our sample exhibits an anti-correlation of h3 - stellar velocity (v/{\sigma}) in these central parts. An increased flattening of the stellar {\sigma} gradient with increasing bar strength supports the notion of bar-induced orbit mixing. These measurements set important constraints on the spatial scales, namely an increasing influence in the central regions (0.1-0.5 bar lengths), revealed by kinematic signatures due to bar-driven secular evolution in present day galaxies.
NIHAO – VIII. Circum-galactic medium and outflows – The puzzles of H i and O vi gas distributions

We study the hot and cold circum-galactic medium (CGM) of 86 galaxies of the cosmological, hydrodynamical simulation suite, Numerical Investigation of a Hundred Astrophysical Objects (NIHAO). NIHAO allows a study of how the z = 0 CGM varies across five orders of magnitude of stellar mass using O VI and HI as proxies for hot and cold gas. The cool HI covering fraction and column density profiles match observations well, particularly in the inner CGM. O VI shows increasing column densities with mass, a trend seemingly echoed in the observations. As in multiple previous simulations, the O VI column densities in simulations are lower than observed and optically thick HI does not extend as far out as in observations. We take a look at the collisional ionization fraction of O VI as a function of halo mass. We make observable predictions of the bipolarity of outflows and their effect on the general shape of the CGM. Bipolar outflows can be seen out to around 40 kpc in intermediate-and low-mass haloes (M-Halo
Efficient matrix-product state method for periodic boundary conditions

We introduce an efficient method to calculate the ground state of one-dimensional lattice models with periodic boundary conditions. The method works in the representation of Matrix Product States (MPS), related to the Density Matrix Renormalization Group (DMRG) method. It improves on a previous approach by Verstraete et al. We introduce a factorization procedure for long products of MPS matrices, which reduces the computational effort from m^5 to m^3, where m is the matrix dimension, and m ~ 100 - 1000 in typical cases. We test the method on the S=1/2 and S=1 Heisenberg chains. It is also applicable to non-translationally invariant cases. The new method makes ground state calculations with periodic boundary conditions about as efficient as traditional DMRG calculations for systems with open boundaries.
MODELING DUST EMISSION OF HL TAU DISK BASED ON PLANET–DISK INTERACTIONS

We use extensive global two-dimensional hydrodynamic disk gas+dust simulations with embedded planets, coupled with three-dimensional radiative transfer calculations, to model the dust ring and gap structures in the HL Tau protoplanetary disk observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). We include the self-gravity of disk gas and dust components and make reasonable choices of disk parameters, assuming an already settled dust distribution and no planet migration. We can obtain quite adequate fits to the observed dust emission using three planets with masses of 0.35, 0.17, and 0.26 MJup at 13.1, 33.0, and 68.6 AU, respectively. Implications for the planet formation as well as the limitations of this scenario are discussed.
A Commonality Modeling Framework for Enhanced Video Coding Leveraging on the Cuboidal Partitioning Based Representation of Frames

Video coding algorithms attempt to minimize the significant commonality that exists within a video sequence. Each new video coding standard contains tools that can perform this task more efficiently compared to its predecessors. Modern video coding systems are block-based wherein commonality modeling is carried out only from the perspective of the block that need be coded next. In this work, we argue for a commonality modeling approach that can provide a seamless blending between global and local homogeneity information. For this purpose, at first the frame that need be coded, is recursively partitioned into rectangular regions based on the homogeneity information of the entire frame. After that each obtained rectangular region’s feature descriptor is taken to be the average value of all the pixels’ intensities encompassing the region. In this way, the proposed approach generates a coarse representation of the current frame by minimizing both global and local commonality. This coarse frame is computationally simple and has a compact representation. It attempts to preserve important structural properties of the current frame which can be viewed subjectively as well as from improved rate-distortion performance of a reference scalable HEVC coder that employs the coarse frame as a reference frame for encoding the current frame.
A Gaia DR2 view of white dwarfs in the Hyades

We have exploited the very precise parallaxes, proper motions, and photometry of Gaia Data Release 2 to study white dwarf members of the Hyades star cluster. Gaia photometry and parallaxes for the eight DA white dwarfs confirmed members have been then used to compute absolute magnitudes and colours. These were compared to three independent sets of white dwarf evolutionary tracks, to derive cooling times and white dwarf (final) masses. All sets of models provide the same mass values, with only small differences in the cooling ages. The precision in the derived masses and cooling ages is typically 1-3 per cent. Our derived masses are generally consistent with spectroscopic estimates from the literature, whilst cooling ages are generally larger. The recent estimate of the cluster age from the Gaia Data Release 2 main-sequence turn offcolour-magnitude diagram (790 Myr) has been employed to derive progenitor (initial) masses. We find a slope of the initial-final mass relation for the Hyades white dwarfs (masses between ~0.67 and ~0.84 M⊙) steeper than that derived for the same mass range from global estimates - averaged over the whole spectrum of white dwarf masses - irrespectively of the cooling models adopted. However, when considering the error in this age estimate (-100+160Myr), a definitive conclusion on this issue cannot be reached yet. The lower limit of 690 Myr (closer to the classical Hyades age of 600-650 Myr) would provide a slope of the initial-final mass relation closer to the global determinations. We also find hints of an intrinsic spread of the cluster initial-final mass relation for the cluster. © 2018 The Author(s).
Tree-level formalism

We review two novel techniques used to calculate tree-level scattering amplitudes efficiently: MHV diagrams, and on-shell recursion relations. For the MHV diagrams, we consider applications to tree-level amplitudes and focus in particular on the supersymmetric formulation. We also briefly describe the derivation of loop amplitudes using MHV diagrams. For the recursion relations, after presenting their general proof, we discuss several applications to massless theories with and without supersymmetry, to theories with massive particles, and to graviton amplitudes in general relativity. This article is an invited review for a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Scattering amplitudes in gauge theories’.
The Foundation Supernova Survey: Measuring Cosmological Parameters with Supernovae from a Single Telescope

Measurements of the dark energy equation-of-state parameter, w, have been limited by uncertainty in the selection effects and photometric calibration of z < 0.1 Type Ia supernovae (SNe Ia). The Foundation Supernova Survey is designed to lower these uncertainties by creating a new sample of z < 0.1 SNe Ia observed on the Pan-STARRS system. Here we combine the Foundation sample with SNe from the Pan-STARRS Medium Deep Survey and measure cosmological parameters with 1338 SNe from a single telescope and a single, well-calibrated photometric system. For the first time, both the low-z and high-z data are predominantly discovered by surveys that do not target preselected galaxies, reducing selection bias uncertainties. The z > 0.1 data include 875 SNe without spectroscopic classifications, and we show that we can robustly marginalize over CC SN contamination. We measure Foundation Hubble residuals to be fainter than the preexisting low-z Hubble residuals by 0.046 ± 0.027 mag (stat + sys). By combining the SN Ia data with cosmic microwave background constraints, we find w = −0.938 ± 0.053, consistent with ΛCDM. With 463 spectroscopically classified SNe Ia alone, we measure w = −0.933 ± 0.061. Using the more homogeneous and better-characterized Foundation sample gives a 55% reduction in the systematic uncertainty attributed to SN Ia sample selection biases. Although use of just a single photometric system at low and high redshift increases the impact of photometric calibration uncertainties in this analysis, previous low-z samples may have correlated calibration uncertainties that were neglected in past studies. The full Foundation sample will observe up to 800 SNe to anchor the LSST and WFIRST Hubble diagrams.
Absolute Proper Motion of IRAS 00259+5625 with VERA : Indication of Superbubble Expansion Motion

We present the first measurement of the absolute proper motions of IRAS 00259+5625 (CB3, LBN594) associated with the HI loop called the "NGC281 superbubble" that extends from the Galactic plane over ~300 pc toward decreasing galactic latitude. The proper motion components measured with VERA are (mu_alpha cos(delta), mu_delta) = (-2.48 +/- 0.32, -2.85 +/- 0.65) mas yr^{-1}, converted into (mu_l cos(b), mu_b) = (-2.72 +/- 0.32, -2.62 +/- 0.65) mas yr^{-1} in the Galactic coordinates. The measured proper motion perpendicular to the Galactic plane (mu_b) shows vertical motion away from the Galactic plane with a significance of about ~4-sigma. As for the source distance, the distance measured with VERA is marginal, 2.4^{+1.0}_{-0.6} kpc. Using the distance, an absolute vertical motion (v_{b}) of -17.9 +/- 12.2 km s^{-1} is determined with ~1.5-sigma significance. The tendency of the large vertical motion is consistent with previous VLBI results for NGC 281 associated with the same superbubble. Thus, our VLBI results indicate the superbubble expansion motion whose origin is believed to be sequential supernova explosions.
Combination of CDF and D0 Results on the Width of the W boson

We summarize and combine direct measurements of the width of the W boson in data collected by the Tevatron experiments CDF and D0 at Fermilab. Results from CDF and D0 RunI (1992-1995) have been combined with the CDF 200 pb^-1 results from the first period of RunII (2001-2004) and the recent 1 fb^-1 result in the electron channel from D0 (2002-2006). The results are corrected for any inconsistencies in parton distribution functions and assumptions about electroweak parameters used in the different analyses. The resulting Tevatron average for the width of the W boson is Gamma_W = 2,046 +- 49.
Different time scales in plasmonically enhanced high-order-harmonic generation

We investigate high-order-harmonic generation in inhomogeneous media for reduced dimensionality models. We perform a phase-space analysis, in which we identify specific features caused by the field inhomogeneity. We compute high-order-harmonic spectra using the numerical solution of the time-dependent Schrodinger equation, and provide an interpretation in terms of classical electron trajectories. We show that the dynamics of the system can be described by the interplay of high-frequency and slow-frequency oscillations, which are given by Mathieu's equations. The latter oscillations lead to an increase in the cutoff energy, and, for small values of the inhomogeneity parameter, take place over many driving-field cycles. In this case, the two processes can be decoupled and the oscillations can be described analytically.
GIANT MOLECULAR CLOUDS AND MASSIVE STAR FORMATION IN THE SOUTHERN MILKY WAY

The Columbia University–Universidad de Chile CO Survey of the southern Milky Way is used to separate the CO(1–0) emission of the fourth Galactic quadrant within the solar circle into its dominant components, giant molecular clouds (GMCs). After the subtraction of an axisymmetric model of the CO background emission in the inner southern Galaxy, 92 GMCs are identified, and for 87 of them the twofold distance ambiguity is solved. Their total molecular mass is M(H2) = 1.14 ± 0.05 × 108 M☉, accounting for around 40% of the molecular mass estimated from an axisymmetric analysis of the H2 volume density in the Galactic disk, M(H2)disk = 3.03 × 108 M☉. The large-scale spiral structure in the southern Galaxy, within the solar circle, is traced by the GMCs in our catalog; three spiral arm segments, the Centaurus, Norma, and 3 kpc expanding arm, are analyzed. After fitting a logarithmic spiral arm model to the arms, tangent directions at 310°, 330°, and 338°, respectively, are found, consistent with previous values from the literature. A complete CS(2–1) survey toward IRAS point-like sources with far-IR colors characteristic of ultracompact H ii regions is used to estimate the massive star formation rate per unit H2 mass (MSFR) and the massive star formation efficiency (ϵ) for GMCs. The average MSFR for GMCs is 0.41 ± 0.06 L☉/M☉, and for the most massive clouds in the Norma arm it is 0.58 ± 0.09 L☉/M☉. Massive star formation efficiencies of GMCs are, on average, 3% of their available molecular mass.
Comparison between charge and spin transport in few-layer graphene

Transport measurements on few-layer graphene (FLG) are important because they interpolate between the properties of single-layer graphene (SLG) as a true two-dimensional material and the three-dimensional bulk properties of graphite. In this article we present four-probe local charge transport and nonlocal spin-valve and spin-precession measurements on lateral spin field-effect transistors on FLG. We study systematically the charge- and spin-transport properties depending on the number of layers and the electrical back gating of the device. We explain the charge-transport measurements by taking the screening of scattering potentials into account and use the results to understand the spin data. The measured samples are between 3 and 20 layers thick, and we include in our analysis our earlier results of the measurements on SLG for comparison. In our room-temperature spin-transport measurements we manage to observe spin signals over distances up to 10 mu m and measure enhanced spin-relaxation times with an increasing number of layers, reaching tau(s) similar to 500 ps as a maximum, about 4 times higher than in SLG. The increase of tau(s) can result from the screening of scattering potentials due to additional intrinsic charge carriers in FLG. We calculate the density of states of FLG using a zone-folding scheme to determine the charge-diffusion coefficient D(C) from the square resistance R(S). The resulting D(C) and the spin-diffusion coefficient D(S) show similar values and depend only weakly on the number of layers and gate-induced charge carriers. We discuss the implications of this on the identification of the spin-relaxation mechanism.
PRIMUS + DEEP2: CLUSTERING OF X-RAY, RADIO, AND IR-AGNs AT z ∼ 0.7

We measure the clustering of X-ray, radio, and mid-IR-selected active galactic nuclei (AGNs) at 0.2<z<1.2 using multi-wavelength imaging and spectroscopic redshifts from the PRIMUS and DEEP2 redshift surveys, covering seven separate fields spanning ∼10. Using the cross-correlation of AGNs with dense galaxy samples, we measure the clustering scale length and slope, as well as the bias, of AGNs selected at different wavelengths. Similar to previous studies, we find that X-ray and radio AGNs are more clustered than mid-IR-selected AGNs. We further compare the clustering of each AGN sample with matched galaxy samples designed to have the same stellar mass, star-formation rate (SFR), and redshift distributions as the AGN host galaxies and find no significant differences between their clustering properties. The observed differences in the clustering of AGNs selected at different wavelengths can therefore be explained by the clustering differences of their host populations, which have different distributions in both stellar mass and SFR. Selection biases inherent in AGN selection therefore determine the clustering of observed AGN samples. We further find no significant difference between the clustering of obscured and unobscured AGNs, using IRAC or Wide-field Infrared Survey Explorer colors or X-ray hardness ratio.