Miracle-dz/UniFAR-FTUs huggingface dataset:
Super Shell Structure of the Magnetic Susceptibility

The magnetic susceptibility of electrons conﬁned to a spherical cavity or a circular billiard shows slow oscillations as a function of the number of electrons, which are a new manifestation of the Super Shell Structure found in the free energy of metal clusters. The relationship of the oscillations of the two diﬀerent quantities is analyzed by means of semiclassical calculations, which are in quantitative agreement with quantal results. The oscillations should be observable for ensembles of circular ballistic quantum dots and metal clusters.
Accretion Disk Assembly During Common Envelope Evolution: Implications for Feedback and LIGO Binary Black Hole Formation

During a common envelope (CE) episode in a binary system, the engulfed companion spirals to tighter orbital separations under the influence of drag from the surrounding envelope material. As this object sweeps through material with a steep radial gradient of density, net angular momentum is introduced into the flow, potentially leading to the formation of an accretion disk. The presence of a disk would have dramatic consequences for the outcome of the interaction because accretion might be accompanied by strong, polar outflows with enough energy to unbind the entire envelope. Without a detailed understanding of the necessary conditions for disk formation during CE, therefore, it is difficult to accurately predict the population of merging compact binaries. This paper examines the conditions for disk formation around objects embedded within CEs using the “wind tunnel” formalism developed by MacLeod et al. We find that the formation of disks is highly dependent on the compressibility of the envelope material. Disks form only in the most compressible of stellar envelope gas, found in envelopes’ outer layers in zones of partial ionization. These zones are largest in low-mass stellar envelopes, but comprise small portions of the envelope mass and radius in all cases. We conclude that disk formation and associated accretion feedback in CE is rare, and if it occurs, transitory. The implication for LIGO black hole binary assembly is that by avoiding strong accretion feedback, CE interactions should still result in the substantial orbital tightening needed to produce merging binaries.
The Age Evolution of the Radio Morphology of Supernova Remnants

Recent hydrodynamical models of supernova remnants (SNRs) demonstrate that their evolution depends heavily on the inhomogeneities of the surrounding medium. As SNRs expand, their morphologies are influenced by the nonuniform and turbulent structure of their environments, as reflected in their radio continuum emission. In this paper, we measure the asymmetries of 96 SNRs in radio continuum images from three surveys of the Galactic plane and compare these results to the SNRs’ radii, which we use as a proxy for their age. We find that larger (older) SNRs are more elliptical/elongated and more mirror asymmetric than smaller (younger) SNRs, though the latter vary in their degrees of asymmetry. This result suggests that SNR shells become more asymmetric as they sweep up the interstellar medium (ISM), as predicted in hydrodynamical models of SNRs expanding in a multiphase or turbulent ISM.
QCD in curved space-time: a conformal bag model

We construct an effective low energy Lagrangian using constraints imposed by the renormalization group. Degrees of freedom are gluons and a scalar glueball. This effective theory has a dual description as classical gluodynamics on a curved conformal background. Color fields are dynamically confined, and the strong coupling freezes at distances larger than the glueball size. We make specific predictions (in particular, on the N{sub c} dependence of glueball properties) which can be tested in lattice simulations of gluodynamics.
The flux-line lattice in superconductors

Magnetic flux can penetrate a type-II superconductor in the form of Abrikosov vortices (also called flux lines, flux tubes, or fluxons) each carrying a quantum of magnetic flux phi 0=h/2e. These tiny vortices of supercurrent tend to arrange themselves in a triangular flux-line lattice (FLL), which is more or less perturbed by material inhomogeneities that pin the flux lines, and in high-Tc superconductors (HTSCs) also by thermal fluctuations. Many properties of the FLL are well described by the phenomenological Ginzburg-Landau theory or by the electromagnetic London theory, which treats the vortex core as a singularity. In Nb alloys and HTSCs the FLL is very soft mainly because of the large magnetic penetration depth lambda . The shear modulus of the FLL is c66~1/ lambda 2, and the tilt modulus c44(k)~(1+k2 lambda 2)-1 is dispersive and becomes very small for short distortion wavelengths 2 pi /k<< lambda . This softness is enhanced further by the pronounced anisotropy and layered structure of HTSCs, which strongly increases the penetration depth for currents along the c axis of these (nearly uniaxial) crystals and may even cause a decoupling of two-dimensional vortex lattices in the Cu-O layers. Thermal fluctuations and softening may `melt` the FLL and cause thermally activated depinning of the flux lines or ofthe two-dimensional `pancake vortices` in the layers. Various phase transitions are predicted for the FLL in layered HTSCs. Although large pinning forces and high critical currents have been achieved, the small depinning energy so far prevents the application of HTSCs as conductors at high temperatures except in cases when the applied current and the surrounding magnetic field are small.
A Superconformal Index for HyperK\"{a}hler Cones

We define an index for osp(4∗|4) superconformal quantum mechanics on a hyperKähler cone. The index is defined on an equivariant symplectic resolution of the cone, which acts as a regulator. We present evidence that the index does not depend on the choice of resolution parameters and encodes information about the spectrum of (semi-) short representations of the superconformal algebra of the unresolved space. In particular, there are two types of multiplet which can be counted exactly using the index. These correspond to holomorphic functions on the cone and to the generators of the Borel-Moore homology on the resolved space respectively. We calculate the resulting index by localisation for a large class of examples.
The Belle II Physics Book

We present the physics program of the Belle II experiment, located on the intensity frontier SuperKEKB e+e- collider. Belle II collected its first collisions in 2018, and is expected to operate for the next decade. It is anticipated to collect 50/ab of collision data over its lifetime. This book is the outcome of a joint effort of Belle II collaborators and theorists through the Belle II theory interface platform (B2TiP), an effort that commenced in 2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II program, which includes a wide scope of physics topics: B physics, charm, tau, quarkonium, electroweak precision measurements and dark sector searches. It is composed of nine working groups (WGs), which are coordinated by teams of theorist and experimentalists conveners: Semileptonic and leptonic B decays, Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm, Quarkonium(like), tau and low-multiplicity processes, new physics and global fit analyses. This book highlights "golden- and silver-channels", i.e. those that would have the highest potential impact in the field. Theorists scrutinised the role of those measurements and estimated the respective theoretical uncertainties, achievable now as well as prospects for the future. Experimentalists investigated the expected improvements with the large dataset expected from Belle II, taking into account improved performance from the upgraded detector.
STABILITY OF ELASTIC GLASS PHASES IN RANDOM FIELD XY MAGNETS AND VORTEX LATTICES IN TYPE-II SUPERCONDUCTORS

A description of a dislocation-free elastic glass phase in terms of domain walls is developed and used as the basis of a renormalization group analysis of the energetics of dislocation loops added to the system. It is found that even after optimizing over possible paths of large dislocation loops, their energy is still very likely to be positive when the dislocation core energy is large. This implies the existence of an equilibrium elastic glass phase in three-dimensional random field XY magnets, and a dislocation-free, bond orientationally ordered {open_quotes}Bragg glass{close_quote}{close_quote} phase of vortices in dirty type-II superconductors. {copyright} {ital 1997} {ital The American Physical Society}
Global-Scale Intraseasonal Oscillations of Outgoing Longwave Radiation and 250 mb Zonal Wind during Northern Hemisphere Summer

Abstract Intraseasonal fluctuations of satellite-based observations of outgoing longwave radiation (OLR) and NMC analyses of 250 mb zonal wind (U250) are described based on global data from nine Northern Hemisphere summers (May–October). Cross-spectral analysis of the 28–72 day spectral band is used to establish statistically significant relationships for the entire data period. Hovmoller diagrams are used to examine individual events and to estimate the oscillation's time scale and propagation characteristics. Intraseasonal OLR fluctuations have their greatest amplitude in the Indian monsoon region and north of the equator in the western tropical Pacific. These two regions have out-of-phase fluctuations and appear to be linked by OLR anomalies propagating eastward (at 3–6 m s−1) along the equator between 50° and 160°E. The OLR oscillation has a preferred time scale of 30–60 days during May–October, based on a sample of more than 30 events. The initiation near the equator of northward-propagating (1–2 m s.
Uso do método multicritério ELECTRE TRI para classificação de estoques na construção civil

The civil construction sector has an important place in the country's economic and social development, producing goods of attendance related to the human necessities or to the productive capacity. The management material process has assumed great relevance due to its strategic role on reducing costs and pushing up the construction companies' technological and organizational innovation. The basic question to be considered is the way that material classification can be done using multiple criteria; hence this procedure is not being use in the construction site and may lead into problems such as lack of materials and production interruption. Thus, this work presents a case study, aiming to present a structuralized multicriteria model to the decision process in the civil construction materials management. The model aim to categorize the material in three classes.
Rheology and microstructure of unsaturated wet granular materials: Experiments and simulations

When dealing with unsaturated wet granular materials, a fundamental question is: What is the effect of capillary cohesion on the bulk flow and yield behavior? We investigate the dense-flow rheology of unsaturated granular materials through experiments and discrete element simulations of homogeneous, simple annular shear flows of frictional, cohesive, spherical particles. Dense shear flows of dry, cohesionless granu-lar materials exhibit three regimes: Quasistatic, inertial, and intermediate [B. Andreotti et al., Contemp. Phys. 55, 151-152 (2013)]. Herewith, we show that the quasistatic and the intermediate regimes persist for unsaturated materials and that the rheology is essentially described by two dimensionless numbers: The reduced pressure P* comparing the cohesive to confining forces and the inertial number I, for a wide range of liquid content. This is consistent with recent numerical simulations [S. Khamseh et al., Phys. Rev. E 92, 022201 (2015)]. Finally, we measure the effective friction coefficient and the solid fraction variation throughout the wet bed. From this, we show that, in the quasistatic regime, the Mohr-Coulomb yield criterion is a good approximation for large enough P*. The experimental results agree quantitatively with the numerical simulation ones, provided the intergranular friction coefficient μ is set to its physical value identified from dry material rheology [M. Badetti et al., Eur. Phys. J. E 41, 68 (2018)]. To directly and quantitatively determine what happens inside the sheared granular bed, x-ray tomography measurements are carried out in a custom-made setup that enables imaging of a wet granular material after different shear histories. For the explored range of liquid content, samples remain homogeneous but exhibit some complex microscopic morphologies far from simple capillary bridges. From the x-ray microtomographic images, we can clearly distinguish liquid capillary bridges and liquid clusters by their morphologies. We see that the total number of capillary bridges decreases when one increases the liquid content and interestingly increases, at the expense of other morphologies, when we increase the shear strain. This explains the concordance between the experimental and numerical measurements since the numerical model is restricted to the pendular state, for which the liquid phase is completely discontin-uous and no coalescence occurs between liquid bridges.
Error free quantum communication through noisy channels

We suggest a method to perform a quantum logic gate between distant qubits by off-resonant field-atom dispersive interactions. The scheme we present is shown to work ideally even in the presence of errors in the photon channels used for communication. The stability against errors arises from the paradoxical situation that the transmitted photons carry no information about the state of the qubits. In contrast to a previous proposal for ideal communication [Phys. Rev. Lett. 78, 4293 (1997)] our proposal only involves single atoms in the sending and receiving devices.
Age Spreads in Star-forming Regions: The Lithium Test in the Orion Nebula Cluster

We present the initial results of a study of the surface lithium abundance in a sample of low-mass members (M* ~ 0.4-1.0 M☉) of the Orion Nebula Cluster (ONC) that provide an independent clock to estimate stellar ages. We report the discovery of a significant depletion of lithium in four stars with estimated masses of ~0.4 M☉ and ages ~10 Myr. Comparison with the predictions of numerical and analytical models shows excellent agreement between the isochronal age and lithium depletion timescale for two objects, the first such case for lithium-poor pre-main-sequence stars. Our results bear on the issue of the real age spread in the ONC and hence on the overall duration of the star formation process, indicating that the stellar population did not come into existence in a single, rapid burst.
Structured extended finite element methods for solids defined by implicit surfaces

A paradigm is developed for generating structured finite element models from solid models by means of implicit surface definitions. The implicit surfaces are defined by radial basis functions. Internal features, such as material interfaces, sliding interfaces and cracks are treated by enrichment techniques developed in the extended finite element method. Methods for integrating the weak form for such models are proposed. These methods simplify the generation of finite element models. Results presented for several examples show that the accuracy of this method is comparable to standard unstructured finite element methods. Copyright © 2002 John Wiley & Sons, Ltd.
Fidelity Mechanics: Analogues of the Four Thermodynamic Laws and Landauer’s Principle

Fidelity mechanics is formalized as a framework for investigating critical phenomena in quantum many-body systems. Fidelity temperature is introduced for quantifying quantum fluctuations, which, together with fidelity entropy and fidelity internal energy, constitute three basic state functions in fidelity mechanics, thus enabling us to formulate analogues of the four thermodynamic laws and Landauer’s principle at zero temperature. Fidelity flows, which are irreversible, are defined and may be interpreted as an alternative form of renormalization group flows. Thus, fidelity mechanics offers a means to characterize both stable and unstable fixed points: divergent fidelity temperature for unstable fixed points and zero-fidelity temperature and (locally) maximal fidelity entropy for stable fixed points. In addition, fidelity entropy behaves differently at an unstable fixed point for topological phase transitions and at a stable fixed point for topological quantum states of matter. A detailed analysis of fidelity mechanical-state functions is presented for six fundamental models—the quantum spin-1/2 XY model, the transverse-field quantum Ising model in a longitudinal field, the quantum spin-1/2 XYZ model, the quantum spin-1/2 XXZ model in a magnetic field, the quantum spin-1 XYZ model, and the spin-1/2 Kitaev model on a honeycomb lattice for illustrative purposes. We also present an argument to justify why the thermodynamic, psychological/computational, and cosmological arrows of time should align with each other, with the psychological/computational arrow of time being singled out as a master arrow of time.
The geometry of photon surfaces

The photon sphere concept in Schwarzschild space–time is generalized to a definition of a photon surface in an arbitrary space–time. A photon sphere is then defined as an SO(3)×R-invariant photon surface in a static spherically symmetric space–time. It is proved, subject to an energy condition, that a black hole in any such space–time must be surrounded by a photon sphere. Conversely, subject to an energy condition, any photon sphere must surround a black hole, a naked singularity or more than a certain amount of matter. A second order evolution equation is obtained for the area of an SO(3)-invariant photon surface in a general nonstatic spherically symmetric space–time. Many examples are provided.
Multiple deformation mechanisms of Ti–22.4Nb–0.73Ta–2.0Zr–1.34O alloy

Ti-22.4Nb-0.73Ta-2.0Zr-1.34O (at. %) alloy after cold compression to similar to 5.2% strain was investigated. The alloy exhibited multiple plastic deformation mechanisms, including the stress-induced alpha(') martensitic (SIM alpha(')) and omega phase transformations, 1/2 dislocations slipping on the {112}beta planes as well as {332} beta and {112} beta twinning, which have not previously been reported to coexist in a titanium alloy. It was also found that beta phase with the {200} planes vertical to the compression direction was almost completely consumed away by a beta -> SIM alpha(') transformation, and a (100) texture of SIM alpha(') formed.
Classical and quantum rotation numbers of asymmetric-top molecules

We study the classical and quantum rotation numbers of the free rotation of asymmetric top molecules. We show numerically that the quantum rotation number converges to its classical analog in the semi-classical limit. Different asymmetric molecules such as the water molecule are taken as illustrative example. A simple approximation of the classical rotation number is derived in a neighborhood of the separatrix connecting the two unstable fixed points of the system. Furthermore, a signature of the classical tennis racket effect in the spectrum of asymmetric molecules is identified.
Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1

We mapped the kinetic temperature structure of the Orion molecular cloud 1 with para-H2CO(303-202, 322-221, and 321-220) using the APEX 12m telescope. This is compared with the temperatures derived from the ratio of the NH3(2,2)/(1,1) inversion lines and the dust emission. Using the RADEX non-LTE model, we derive the gas kinetic temperature modeling the measured averaged line ratios of para-H2CO 322-221/303-202 and 321-220/303-202. The gas kinetic temperatures derived from the para-H2CO line ratios are warm, ranging from 30 to >200 K with an average of 62 K at a spatial density of 10$^5$ cm$^{-3}$. These temperatures are higher than those obtained from NH3(2,2)/(1,1) and CH3CCH(6-5) in the OMC-1 region. The gas kinetic temperatures derived from para-H2CO agree with those obtained from warm dust components measured in the mid infrared (MIR), which indicates that the para-H2CO(3-2) ratios trace dense and warm gas. The cold dust components measured in the far infrared (FIR) are consistent with those measured with NH3(2,2)/(1,1) and the CH3CCH(6-5) line series. With dust at MIR wavelengths and para-H2CO(3-2) on one side and dust at FIR wavelengths, NH3(2,2)/(1,1), and CH3CCH(6-5) on the other, dust and gas temperatures appear to be equivalent in the dense gas of the OMC-1 region, but provide a bimodal distribution, one more directly related to star formation than the other. The non-thermal velocity dispersions of para-H2CO are positively correlated with the gas kinetic temperatures in regions of strong non-thermal motion (Mach number >2.5) of the OMC-1, implying that the higher temperature traced by para-H2CO is related to turbulence on a 0.06 pc scale. Combining the temperature measurements with para-H2CO and NH3(2,2)/(1,1) line ratios, we find direct evidence for the dense gas along the northern part of the OMC-1 10 km s$^{-1}$ filament heated by radiation from the central Orion nebula.
Symbol of the Dirichlet-to-Neumann operator in 2D diffraction problems with large wavenumber

Consider the Dirichlet-to-Neumann operator N in the exterior problem for the 2D Helmholtz equation outside a bounded domain with smooth boundary. Using parametrization of the boundary by normalized arclength, we treat N as a pseudodifferential operator on the unit circle. We study its discrete symbol. We put, forward a conjecture on the universal behaviour, independent of shape and curvature of the boundary, of the symbol as the wavenumber k /spl rarr/ /spl infin/. The conjecture is motivated by an explicit formula for circular boundary, and confirmed numerically for other shapes. It also agrees, on a physical level of rigor, with Kirchhoff's approximation. The conjecture, if true, opens new ways in numerical analysis of diffraction in the range of moderately high frequencies.
Conditional preparation of maximal polarization entanglement

A simple experimental setup consisting of a spontaneous parametric down-conversion source and passive linear optics is proposed for conditional preparation of a maximally entangled polarization state of two photons. Successful preparation is unambiguously heralded by coincident detection of four auxiliary photons. The proposed scheme utilizes the down-conversion term corresponding to the generation of three pairs of photons. We analyze imperfect detection of the auxiliary photons and demonstrate that its deleterious effect on the fidelity of the prepared state can be suppressed at the cost of decreasing the efficiency of the scheme.
Spin fluctuations and black hole singularities: the onset of quantum gravity is spacelike

Due to quantum fluctuations, a black hole of mass M represents an average over an ensemble of black hole geometries with angular momentum. This observation is apparently at odds with the fact that the curvature singularity inside a rotating black hole is timelike, while the one inside a non-rotating black hole is spacelike. Is the average of timelike singularities really spacelike? We use the Bekenstein–Hawking entropy formula to introduce a microcanonical ensemble for spin fluctuations and show that the onset of quantum gravity is always spacelike. We discuss the impact of this result on singularity resolution in quantum gravity and hint at the possibility of an observational test.