ShantanuT01/DACTYL-Pretraining huggingface dataset:
The magnetization measurements of CexLa1-xRu2Al10 (x = 1, 0.75) under the high magnetic field were performed in order to obtain the information for the long-range order (LRO) in CeRu2Al10. We successfully obtained the magnetic phase diagram of these two compounds for the applied magnetic field along the a-axis which is the magnetization easy axis, and found that the LRO for x = 1 disappears at ~50 T which is the critical field to the paramagnetic phase. For x = 0.75, the critical magnetic field decreases to ~37 T by La substitution. The magnetic phase diagram and magnetization curve are qualitatively consistent with the recent Hanzawa's mean field calculation results obtained by assuming the dimer of Ce ions whose crystalline electric field ground state has a large magnetic anisotropy. These results support the singlet pair formation scenario recently proposed by Tanida et al.. We also pointed out the possibility of the appearance of the field-induced magnetic phase between ~40 T and ~50 T for x = 1.
We present here an atomistic theory of the electronic and optical properties of hexagonal InAsP quantum dots in InP nanowires in the wurtzite phase. These self-assembled quantum dots are unique in that their heights, shapes, and diameters are well known. Using a combined valence-force-field, tight-binding, and configuration-interaction approach we perform atomistic calculations of single-particle states and excitonic, biexcitonic and trion complexes as well as emission spectra as a function of the quantum dot height, diameter and As versus P concentration. The atomistic tight-binding parameters for InAs and InP in the wurtzite crystal phase were obtained by ab initio methods corrected by empirical band gaps. The low energy electron and hole states form electronic shells similar to parabolic or cylindrical quantum confinement, only weakly affected by hexagonal symmetry and As fluctuations. The relative alignment of the emission lines from excitons, trions and biexcitons agrees with that for InAs/InP dots in the zincblende phase in that biexcitons and positive trions are only weakly bound. The random distribution of As atoms leads to dot-to-dot fluctuations of a few meV for the single-particle states and the spectral lines. Due to the high symmetry of hexagonal InAsP nanowire quantum dots the exciton fine structure splitting is found to be small, of the order a few $\mu$eV with significant random fluctuations in accordance with experiments.
Observation of coronal EUV spectral lines sensitive to different temperatures offers an opportunity to evaluate the thermal structure and flows in flaring atmospheres. This can be used to estimate the partitioning between the thermal and kinetic energies. Our aim is to model large-scale (50-10000km) velocity distributions in order to interpret non-thermal broadening of different spectral EUV lines. The developed models allow us to understand the origin of the observed spectral line shifts and broadening, and link these features to particular physical effects in flaring atmospheres. We use ideal MHD to derive twisted magnetic fluxtube configurations in a stratified atmosphere. The evolution of these fluxtubes is followed using resistive MHD, with anomalous resistivity depending on the local density and temperature. The model also takes into account the thermal conduction and radiative losses. The model allows us to evaluate average velocities and velocity dispersions, which would be interpreted as `non-thermal' velocities in observations, at different temperatures for different parts of the models. Our models show qualitative and quantitative agreement with observations. The line-of-sight (LOS) velocity dispersions demonstrate substantial correlation with the temperature, increasing from about 20-30 km/s around 1 MK to about 200-400 km/s near 10-20 MK. The average LOS velocities also correlate with velocity dispersions, although they demonstrate a very strong scattering, compared to observations. We also note that near foot-points the velocity dispersions across the magnetic field are systematically lower than those along the field. We conclude, that the correlation between the flow velocities, velocity dispersions and temperatures are likely to indicate that the same heating mechanism is responsible for heating the plasma, its turbulisation and expansion/evaporation.
This paper is devoted to present two counterexamples to the theorem from \cite{MK} Maria R., Katherine T. M., Bernardo S. M., Extremal graphs with bounded vertex bipartiteness number, Linear Algebra Appl. 493 (2016) 28-36. Moreover, the corrected theorem and proof are presented.
We discuss issues related to the resummation of non-global observables in QCD, those that are sensitive to radiation in only a part of phase space. Examples of such observables are certain single-hemisphere event shapes in e+e- and DIS. Compared to global observables (those sensitive to all emissions, e.g. the e+e- thrust) a new class of single-logarithmic terms arises. These have been neglected in recent calculations in the literature. For a whole set of single hemisphere e+e- and DIS event shapes, we analytically evaluate the first such term, at order alpha_s^2, and give numerical results for the resummation of these terms in the large-Nc limit.
In this paper, we prove new Strichartz estimates for linear Schrodinger equations posed on d-dimensional irrational tori. Then, we use these estimates to prove subcritical and critical local well-posedness results for nonlinear Schrodinger equations (NLS) on irrational tori.
We report the first calculations of nuclear properties near the drip-lines using the spherical Hartree-Fock-Bogoliubov mean-field theory with a finite-range force supplemented by continuum and particle number projection effects. Calculations were carried out in a basis made of the eigenstates of a Woods-Saxon potential computed in a box, thereby garanteeing that continuum effects were properly taken into account. Projection of the self-consistent solutions on good particle number was carried out after variation, and an approximation of the variation after projection result was used. We give the position of the drip-lines and examine neutron densities in neutron-rich nuclei. We discuss the sensitivity of nuclear observables upon continuum and particle-number restoration effects.
Lecture notes of lectures delivered at the Hodge Theory Summer School in ICTP Trieste, June 2010.
The question of the averaging of inhomogeneous spacetimes in cosmology is important for the correct interpretation of cosmological data. In this paper we suggest a conceptually simpler approach to averaging in cosmology based on the averaging of scalars within unimodular gravity. As an illustration, we consider the example of an exact spherically symmetric dust model, and show that within this approach averaging introduces correlations (corrections) to the effective dynamical evolution equation in the form of a spatial curvature term.
This is a completely rewritten version of the paper formerly entitled "Sheaves of Iwasawa modules, moment maps and the $\ell$-adic elliptic polylogarithm". The proof of the main result is also simplified.   In the paper we study systematically the $\ell$-adic realization of the elliptic polylogarithm in the context of sheaves of Iwasawa modules. This leads to a description of the elliptic polylogarithm in terms of elliptic units. As an application we prove a precise relation between $\ell$-adic Eisenstein classes and elliptic Soul\'e elements. This allows to give a new proof of the formula for the residue of the $\ell$-adic Eisenstein classes at the cusps and reproves the formula for the cup-product construction in \cite{Huber-Kings99}.   The paper is the elaboration of lectures given at the Pune-Workshop on the proof of the Bloch-Kato conjectures for the Riemann zeta function in 2012.
We provide a survey of results concerning both the direct and inverse problems to the Cauchy-Davenport theorem and Erdos-Heilbronn problem in Additive Combinatorics. We prove a slight extension to an inverse theorem of Dias da Silva-Hamidoune in Z/pZ, and we present a counterexample to an open conjecture concerning the inverse Erdos-Heilbronn problem in nonabelian groups.
Recent calculations of the effects of hadronization and final state interaction (FSI) in semi-exclusive deep-inelastic scattering (DIS) $A(e,e'(A-1))X$ processes are reviewed. The basic ingredient underlying these calculations, {\it viz} the time-dependent effective debris-nucleon cross section is illustrated, and some relevant results on complex nuclei and the deuteron are presented. In the latter case, particular attention is paid to the choice of the kinematics, for such a choice would in principle allow one to investigate both the structure function of a bound nucleon as well as the hadronization mechanisms. It is stressed that a planned experiment at Jlab on the process $D(e,e'p)X$ could be very useful in that respect.
We report on calorimetry under applied hydrostatic pressure and magnetic field at the antiferromagnetic (AFM)-ferromagnetic (FM) transition of Fe$_{49}$Rh$_{51}$. Results demonstrate the existence of a giant barocaloric effect in this alloy, a new functional property that adds to the magnetocaloric and elastocaloric effects previously reported for this alloy. All caloric effects originate from the AFM/FM transition which encompasses changes in volume, magnetization and entropy. The strong sensitivity of the transition temperatures to both hydrostatic pressure and magnetic field confers to this alloy outstanding values for the barocaloric and magnetocaloric strengths ($|\Delta S|$/$\Delta p$ $\sim$ 12 J kg$^{-1}$ K $^{-1}$ kbar$^{-1}$ and $|\Delta S|$/$\mu_0\Delta H$ $\sim$ 12 J kg$^{-1}$ K$^{-1}$ T$^{-1}$). Both barocaloric and magnetocaloric effects have been found to be reproducible upon pressure and magnetic field cycling. Such a good reproducibility and the large caloric strengths make Fe-Rh alloys particularly appealing for solid-state cooling technologies at weak external stimuli.
We report on Coulomb blockade and Coulomb diamond measurements on an etched, tunable single-layer graphene quantum dot. The device consisting of a graphene island connected via two narrow graphene constrictions is fully tunable by three lateral graphene gates. Coulomb blockade resonances are observed and from Coulomb diamond measurements a charging energy of ~3.5 meV is extracted. For increasing temperatures we detect a peak broadening and a transmission increase of the nanostructured graphene barriers.
Faraday rotation of linearly polarized radio signals provides a very sensitive probe of fluctuations in the interstellar magnetic field and ionized gas density resulting from magnetohydrodynamic (MHD) turbulence. We used a set of statistical tools to analyze images of the spatial gradient of linearly polarized radio emission ($|\nabla \textbf{P}|$) from the ISM for both observational data from a test image of the Southern Galactic Plane Survey (SGPS) and isothermal simulations of MHD turbulence. We compared the observational data with results of synthetic observations obtained with the simulations of 3D turbulence. Visually, in both data sets, a complex network of filamentary structures is seen. Our analysis shows that the filaments in the gradient can be produced by shocks as well as random fluctuations characterizing the non-differentiable field of MHD turbulence. The latter dominates for subsonic turbulence, while the former dominates for supersonic turbulence. In order to quantitatively characterize these differences we use the topology tool known as a genus curve as well as the moments of the image distribution. We find that higher values for the moments correspond to cases of $|\nabla \textbf{P}|$ with larger Mach numbers, but the strength of the dependency is connected to the telescope angular resolution. In regards to the topology, the supersonic filaments observed in $|\nabla \textbf{P}|$ have a positive genus shift, which indicates a "swisscheese" like topology, while the subsonic cases show a negative genus, indicating a "clump" like topology. In the case of the genus, the dependency on the telescope resolution is not as strong. The SGPS test region data has a distribution and morphology that matches subsonic to transsonic type turbulence, which independently confirms what is now expected for the WIM.
We present high-resolution HST images of all 35 AGNs with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution to ground-based spectroscopic luminosity measurements at 5100A. After correcting the luminosities of the AGNs for the contribution from starlight, we re-examine the Hbeta R-L relationship. Our best fit for the relationship gives a powerlaw slope of 0.52 with a range of 0.45 - 0.59 allowed by the uncertainties. This is consistent with our previous findings, and thus still consistent with the naive assumption that all AGNs are simply luminosity-scaled versions of each other. We discuss various consistency checks relating to the galaxy modeling and starlight contributions, as well as possible systematic errors in the current set of reverberation measurements from which we determine the form of the R-L relationship.
In this note, we consider a nonlinear diffusion equation with a bistable reaction term arising in population dynamics. Given a rather general initial data, we investigate its behavior for small times as the reaction coefficient tends to infinity: we prove a generation of interface property.
Universal quantum computers promise a dramatic speed-up over classical computers but a full-size realization remains challenging. However, intermediate quantum computational models have been proposed that are not universal, but can solve problems that are strongly believed to be classically hard. Aaronson and Arkhipov have shown that interference of single photons in random optical networks can solve the hard problem of sampling the bosonic output distribution which is directly connected to computing matrix permanents. Remarkably, this computation does not require measurement-based interactions or adaptive feed-forward techniques. Here we demonstrate this model of computation using high--quality laser--written integrated quantum networks that were designed to implement random unitary matrix transformations. We experimentally characterize the integrated devices using an in--situ reconstruction method and observe three-photon interference that leads to the boson-sampling output distribution. Our results set a benchmark for quantum computers, that hold the potential of outperforming conventional ones using only a few dozen photons and linear-optical elements.
In this work, we continue the study of the central region of NGC 613 by da Silva et al. (2020), by analysing the stellar and gas kinematics and the stellar archaeology in optical and near-infrared data cubes. The high spatial resolution of the Gemini Multi-Object Spectrograph (GMOS) data cube allowed the detection, using spectral synthesis methods, of an inner circumnuclear ring, with a radius of $\sim$ 1 arcsec, composed of $\sim$ 10$^9$-yr stellar populations. Such a ring is located between the nucleus and the circumnuclear ring composed by H II regions detected in previous works. Besides that, there is a stellar rotation around the nucleus and the rings follow the same direction of rotation with different velocities. The intensity-weighted average stellar velocity dispersion at the centre is 92 $\pm$ 3 km s$^{-1}$. Three distinct gas outflow components were detected. The direction of the outflow observed with the H $\alpha$ emission line is compatible with the direction of the previously observed radio jet. The direction of one of the outflows detected in the [O III]$\lambda$5007 emission coincides with the axis of the ionization cone. There is no difference regarding the stellar populations and the stellar kinematics along the double stellar emission, probably separated by a dust lane as mentioned in Paper I, confirming that they are part of the same structure.
Strong gravitational lenses are a rare and instructive type of astronomical object. Identification has long relied on serendipity, but different strategies -- such as mixed spectroscopy of multiple galaxies along the line of sight, machine learning algorithms, and citizen science -- have been employed to identify these objects as new imaging surveys become available.   We report on the comparison between spectroscopic, machine learning, and citizen science identification of galaxy-galaxy lens candidates from independently constructed lens catalogs in the common survey area of the equatorial fields of the GAMA survey. In these, we have the opportunity to compare high-completeness spectroscopic identifications against high-fidelity imaging from the Kilo Degree Survey (KiDS) used for both machine learning and citizen science lens searches.   We find that the three methods -- spectroscopy, machine learning, and citizen science -- identify 47, 47, and 13 candidates respectively in the 180 square degrees surveyed. These identifications barely overlap, with only two identified by both citizen science and machine learning. We have traced this discrepancy to inherent differences in the selection functions of each of the three methods, either within their parent samples (i.e. citizen science focuses on low-redshift) or inherent to the method (i.e. machine learning is limited by its training sample and prefers well-separated features, while spectroscopy requires sufficient flux from lensed features to lie within the fiber). These differences manifest as separate samples in estimated Einstein radius, lens stellar mass, and lens redshift. The combined sample implies a lens candidate sky-density $\sim0.59$ deg$^{-2}$ and can inform the construction of a training set spanning a wider mass-redshift space.
We establish a regularity criterion for weak solutions of the dissipative quasi-geostrophic equations in mixed time-space Besov spaces.
Atomic gas in the diffuse interstellar medium (ISM) is organized in filamentary structures. These structures usually host cold and dense molecular clumps. The Galactic magnetic field is considered to play an important role in the formation of these clumps. Our goal is to explore the role of the magnetic field in the HI - H$_{2}$ transition process. We targeted a filamentary cloud where gas transitions from atomic to molecular. This cloud is located at the edges of an expanding structure, known as the North Celestial Pole Loop (NCPL). We probed the magnetic field properties of the cloud with optical polarization observations. We performed multi-wavelength spectroscopic observations of different species in order to probe the gas phase properties of the cloud. We identified two distinct sub-regions within the cloud. One of the regions hosts purely atomic gas, while the other is dominated by molecular gas although most of it is CO-dark. The estimated plane-of-the-sky magnetic field strength between the two regions remains constant within uncertainties and lies in the range 20 ~ 30$~\mu$G. The total magnetic field strength does not scale with density which implies that gas is compressed along the field lines. We also found that turbulence is sub-Alfv\'enic. The HI velocity gradients are in general perpendicular to the mean magnetic field orientation, except for the region close to the CO clump where they tend to become parallel. The latter is likely related to gas undergoing gravitational infall. The magnetic field morphology of the target cloud is parallel to the HI column density structure of the cloud in the atomic region, while it tends to become perpendicular to the HI structure in the molecular region. If this is verified in more cases it has important consequences for the ISM magnetic field modeling with HI data.
The merger of a double neutron star (NS-NS) binary may result in a rapidly rotating massive NS with an extremely strong magnetic field (i.e., a millisecond magnetar). In this case, the magnetic spin-down of the NS remnant provides an additional source of sustained energy injection, which would continuously power the merger ejecta. The thermal emission from the merger ejecta would give rise to a bright optical "magnetar-powered merger-nova". In this work, we carry out a complete search for magnetar-powered merger-nova from Swift short gamma-ray burst (SGRB) sample. We focus on short GRBs with extended emission or internal plateau, which may signify the presence of magnetars as the central engine. We eventually find three candidates of magnetar-powered merger-nova from the late observations of GRB 050724, GRB 070714B and GRB 061006. With standard parameter values, the magnetar remnant scenario could well interpret the multi-band data of all three bursts, including the extended emission and their late chromatic features in the optical and X-ray data. The peak luminosities of these merger-novae reach several times $10^{42}~{\rm erg~s^{-1}}$, more than one order of magnitude brighter than the traditional "kilo-novae" with peak luminosity of $\sim 10^{41}~{\rm erg~s^{-1}}$. Intense, multi-color late time observations of short GRBs are encouraged to identify more merger-novae in the future.
The beam-splitter (BS) is one of the most common and important components in modern optics, and lossless BS which features unitary transformation induces Hermitian evolution of light. However, the practical BS based on the conversion between different degree of freedoms are naturally non-Hermitian, as a result of essentially open quantum dynamics. In this work, we experimentally demonstrate a non-Hermitian BS for the interference between traveling photonic and localized magnonic modes. The non-Hermitian magnon-photon BS is achieved by the coherent and incoherent interaction mediated by the excited levels of atoms, which is reconfigurable by adjusting the detuning of excitation. Unconventional correlated interference pattern is observed at the photon and magnon output ports. Our work is potential for extending to single-quantum level to realize interference between a single photon and magnon, which provides an efficient and simple platform for future tests of non-Hermitian quantum physics.
The stability under small time perturbations of the dilatonic black hole solution near the determinant curvature singularity is proved. This fact gives the additional arguments that the investigated topological configuration can realise in nature. In the frames of this model primordial black hole remnants are examined as time stable objects, which can form an significant part of a dark matter in the Universe.
Neutral excitons in strained axially symmetric In(Ga)As/GaAs quantum dots with ringlike shape are investigated. Similar to experimental self-assembled quantum rings, the analyzed quantum dots have volcano-like shapes. The continuum mechanical model is employed to determine the strain distribution, and the single-band envelope function approach is adopted to compute the electron states. The hole states are determined by the axially symmetric multiband Luttinger-Kohn Hamiltonian, and the exciton states are obtained from an exact diagonalization. We found that the presence of the inner layer covering the ring opening enhances the excitonic Aharonov-Bohm (AB) oscillations. The reason is that the hole becomes mainly localized in the inner part of the quantum dot due to strain, whereas the electron resides mainly inside the ring-shaped rim. Interestingly, larger AB oscillations are found in the analyzed quantum dot than in a fully opened quantum ring of the same width. Comparison with the unstrained ring-like quantum dot shows that the amplitude of the excitonic Aharonov-Bohm oscillations are almost doubled in the presence of strain. The computed oscillations of the exciton energy levels are comparable in magnitude to the oscillations measured in recent experiments.