ShantanuT01/DACTYL-Pretraining huggingface dataset:
The pseudo SU(3) approach has been used to describe many low-lying rotational bands, as well as BE(2) and B(M1) intensities in rare earth and actinide nuclei, both with even-even and odd-mass numbers . The double beta half lives of some of these parent nuclei to the ground and excited states of the daughter ones were evaluated for the two and zero neutrino emitting modes using the pseudo SU(3) scheme. The predictions were in good agreement with the available experimental data for 150Nd and 238U.   The double electron capture half-lives of 156Dy, 162Er and 168Yb were also studied using the same formalism. The first nuclei was found to be the best candidate for experimental detection, with a half-life of 10^24 yr to the first excited 0+ state in 156Gd. There are strong selection rules which restrict the two neutrino mode of the double beta decay in some other nuclei, including 160Gd. Experimental limits for the double beta decay of 160Gd have been reported . Recently it was argued that the strong cancellation of the 2nu mode in the double beta decay of 160Gd would suppress the background for the detection of the 0nu mode.   In the present contribution we extend the previous research evaluating the double beta half lives of 160Gd using the pseudo SU(3) model. While the 2nu mode is forbidden when the most probable occupations are considered, states with different occupation numbers can be mixed through the pairing interaction. The amount of this mixing is evaluated using perturbation theory. The possibility of observing the double beta decay in 160Gd is discussed for both the 2nu and 0nu modes.
In this paper we prove a relation between the period of an elliptic curve and the period of its real and imaginary quadratic twists. This relation is often misstated in the literature.
Nanodots with magnetic vortices have many potential applications, such as magnetic memories (VRAMs) and spin transfer nano-oscillators (STNOs). Adding a perpendicular anisotropy term to the magnetic energy of the nanodot it becomes possible to tune the vortex core properties. This can be obtained, e.g., in Co nanodots by varying the thickness of the Co layer in a Co/Pt stack. Here we discuss the spin configuration of circular and elliptical nanodots for different perpendicular anisotropies; we show for nanodisks that micromagnetic simulations and analytical results agree. Increasing the perpendicular anisotropy, the vortex core radii increase, the phase diagrams are modified and new configurations appear; the knowledge of these phase diagrams is relevant for the choice of optimum nanodot dimensions for applications. MFM measurements on Co/Pt multilayers confirm the trend of the vortex core diameters with varying Co layer thicknesses.
Results on the behaviour of the rightmost particle in the $n$th generation in the branching random walk are reviewed and the phenomenon of anomalous spreading speeds, noticed recently in related deterministic models, is considered. The relationship between such results and certain coupled reaction-diffusion equations is indicated.
The design and the simulated performances of a compact detector dedicated to the measurement of GRB photon polarization is presented. Such a detector would permit to answer the question ``are most of the GRB strongly polarized?'' in a mission of one year in space.
We show that high quality laser guide star (LGS) adaptive optics (AO) observations of nearby early-type galaxies are possible when the tip-tilt correction is done by guiding on nuclei while the focus compensation due to the changing distance to the sodium layer is made 'open loop'. We achieve corrections such that 40% of flux comes from R<0.2 arcsec. To measure a black hole mass (Mbh) one needs integral field observations of both high spatial resolution and large field of view. With these data it is possible to determine the lower limit to Mbh even if the spatial resolution of the observations are up to a few times larger than the sphere of influence of the black hole.
We investigate a condensed matter ``black hole'' analogue, taking the Gross-Pitaevskii (GP) equation as a starting point. The linearized GP equation corresponds to a wave equation on a black hole background, giving quasinormal modes under some appropriate conditions. We suggest that we can know the detailed characters and corresponding geometrical information about the acoustic black hole by observing quasinormal ringdown waves in the low temperature condensed matters.
We investigate the zero-temperature coarsening dynamics of a chain of Ising spins with a nearest-neighbor ferromagnetic and an nth-neighbor antiferromagnetic interactions. For sufficiently large antiferromagnetic interaction, the ground state consists of $n$ consecutive up spins followed by n down spins, etc. We show that the asymptotic coarsening into this ground state is governed by a multispecies reactive gas of elementary excitations. The basic elementary excitations are identified and each decays at a different power-law rate in time. The dominant excitations are domains of n+1 spins which diffuse freely and disappear through processes which are effectively governed by (n+1)-particle annihilation. This implies that the ground state is approached slowly with time, as t^{-1/n}.
In this paper, we establish the relationship between backward stochastic Volterra integral equations (BSVIEs, for short) and a kind of non-local quasilinear (and possibly degenerate) parabolic equations. We first introduce the extended backward stochastic Volterra integral equations (EBSVIEs, for short). Under some mild conditions, we establish the well-posedness of EBSVIEs and obtain some regularity results of the adapted solution to the EBSVIEs via Malliavin calculus. We show that a given function expressed in terms of the solution to the EBSVIEs solves a certain system of non-local parabolic partial differential equations (PDEs, for short), which generalizes the famous nonlinear Feynman-Kac formula in Pardoux{Peng [21].
We discuss the dense molecular gas in central regions of nearby Seyfert galaxies, and report new arcsec resolution observations of HCN(1-0) and HCO$^+$(1-0) for 3 objects. In NGC 3079 the lines show complex profiles as a result of self-absorption and saturated continuum absorption. H$^{13}$CN reveals the continuum absorption profile, with a peak close to the galaxy's systemic velocity that traces disk rotation, and a second feature with a blue wing extending to $-350$km s$^{-1}$ that most likely traces a nuclear outflow. The morphological and spectral properties of the emission lines allow us to constrain the dense gas dynamics. We combine our kinematic analysis for these 3 objects, as well as another with archival data, with a previous comparable analysis of 4 other objects, to create a sample of 8 Seyferts. In 7 of these, the emission line kinematics imply thick disk structures on radial scales of $\sim$100pc, suggesting such structures are a common occurrence. We find a relation between the circumnuclear LHCN and Mdyn that can be explained by a gas fraction of 10% and a conversion factor {\alpha}HCN $\sim$ 10 between gas mass and HCN luminosity. Finally, adopting a different perspective to probe the physical properties of the gas around AGN, we report on an analysis of molecular line ratios which indicates that the clouds in this region are not self-gravitating.
In this paper we prove the equidistribution of bounded sequences of special subvarieties in a general mixed Shimura varieties, a notion adapted from the pure case treated by Clozel, Ullmo, and Yafaev in the study of the Andre-Oort conjecture. We also discuss the relation of bounded sequences with bounded Galois orbits of special subvarieties.
A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of $128^3$ cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.
Here I will outline successes and challenges for finding spectral line sources in large data cubes that are dominated by noise. This is a 3D challenge as the sources we wish to catalog are spread over several spatial pixels and spectral channels. While 2D searches can be applied, e.g., channel by channel, optimal searches take into account the 3-dimensional nature of the sources. In this overview I will focus on HI 21-cm spectral line source detection in extragalactic surveys, in particular HIPASS, the "HI Parkes All-Sky Survey" and WALLABY, the "ASKAP HI All-Sky Survey". I use the original HIPASS data to highlight the diversity of spectral signatures of galaxies and gaseous clouds, both in emission and absorption. Among others, I report the discovery of a 680 km/s wide HI absorption trough in the megamaser galaxy NGC 5793. Issues such as source confusion and baseline ripples, typically encountered in single-dish HI surveys, are much reduced in interferometric HI surveys. Several large HI emission and absorption surveys are planned for the Australian Square Kilometre Array Pathfinder (ASKAP): here we focus on WALLABY, the 21-cm survey of the sky (Dec < +30 degr; z < 0.26) which will take about one year of observing time with ASKAP. Novel phased array feeds ("radio cameras") will provide 30 square degrees instantaneous field-of-view. WALLABY is expected to detect more than 500 000 galaxies, unveil their large-scale structures and cosmological parameters, detect their extended, low-surface brightness disks as well as gas streams and filaments between galaxies. It is a precursor for future HI surveys with SKA Phase I and II, exploring galaxy formation and evolution. The compilation of highly reliable and complete source catalogs will require sophisticated source-finding algorithms as well as accurate source parametrisation.
The dissipative curve-crossing problem provides a paradigm for electron-transfer (ET) processes in condensed media. It establishes the simplest conceptual test bed to study the influence of the medium's dynamics on ET kinetics both on the ensemble level, and on the level of single particles. Single electron description is particularly important for nanoscale systems. Slow medium's dynamics is capable to enslave ET and bring it on the ensemble level from a quantum regime of non-adiabatic tunneling to the classical adiabatic regime, where electrons just follow the nuclei rearrangements. This classical adiabatic textbook picture contradicts, however, in a very spectacular fashion to the statistics of single electron transitions, even in the Debye, memoryless media, named also Ohmic in the parlance of the famed spin-boson model. On the single particle level, ET remains always quantum and this was named a quantum breaking of ergodicity in the adiabatic ET regime. What happens in the case of subdiffusive, fractional, or sub-Ohmic medium's dynamics, which is featured by power-law decaying dynamical memory effects pertinent e.g. for protein macromolecules, and other viscoelastic media? Such a memory is vividly manifested by anomalous Cole-Cole dielectric response typical for such media. This is the question which is addressed in this work based both on precise numerics and analytical semi-classical theory. The ensemble theory remarkably agrees with the numerical dynamics of electronic populations, revealing a power law relaxation tail even in a deeply non-adiabatic electron transfer regime. However, a profound difference with the numerically accurate results emerges for the distribution of residence times in the electronic states, both on the ensemble level and on the level of single trajectories. Ergodicity is broken dynamically even in a more spectacular way than in the memoryless case.
The stability, electronic and optical properties of single-walled carbon nanotubes (CNTs) and graphene noncovalently functionalized with free-base tetraphenylporphyrin (TPP) molecules is addressed by density functional theory calculations, including corrections to dispersive interactions. We study the TPP physisorption on 42 CNT species, particularly those with chiral indices ($n$,$m$), where $5 \leq n \leq 12$ and $0\leq m\leq n$. Our results show a quite strong $\pi$-$\pi$ interaction between TPP and the CNT surface, with binding energies ranging from 1.1 to 1.8 eV, where higher energies can be associated with increasing CNT diameters. We also find that the TPP optical absorptions would not be affected by the CNT diameter or chirality. Results for the TPP physisorption on graphene show a remarkable stability with binding energy of 3.2 eV, inducing a small redshift on the $\pi$-stacked TPP absorption bands. The strong graphene-TPP interaction also induces a charge transfer from TPP to graphene, indicating a $n$-type doping mechanism without compromising the graphene structure.
In this paper we present a new, essentially empirical, model for the relation between the mass of a dark matter halo/subhalo and the luminosity of a galaxy hosted in it. To estimate this, we replace the assumption of linearity between light and mass fluctuations with the assumption of monotonicity between galaxy light and halo or subhalo mass. We are enabled to proceed with this less restrictive ansatz by the availability of new, very high resolution dark matter simulations and more detailed and comprehensive global galactic luminosity functions.   We find that the relation between halo/subhalo mass and hosted galaxy luminosity is fairly well fit by a double power law, while that between halo mass and group luminosity is fairly well fit by a two branch function, with both branches double power laws. Both relations asymptote to $L\propto M^4$ at low $M$, while at high mass the former follows $L\propto M^{0.28}$ and the latter $L\propto M^{0.9}$.   We also derive results for the occupation number, luminosity function of cluster galaxies, group luminosity function and multiplicity function. Then, using some additional assumptions, we further derive results for biasing between mass and light and mass and galaxy number, light distribution function and the void probability distribution. Our results for the most part seem to match well with observations and previous expectations. We feel this is a potentially powerful way of modelling this relation, since the main inputs are readily testable against dark matter simulation results and galaxy surveys. (abridged)
This is a write-up of the lectures given in Young Researchers Integrability School 2017. The main goal is to explain the connection between the ODE/IM correspondence and the classical integrability of strings in AdS. As a warm up, we first discuss the classical three-point function of the Liouville theory. The starting point is the well-known fact that the classical solutions to the Liouville equation can be constructed by solving a Schrodinger-like differential equation. We then convert it into a set of functional equations using a method similar to the ODE/IM correspondence. The classical three-point functions can be computed directly from these functional equations, and the result matches with the classical limit of the celebrated DOZZ formula. We then discuss the semi-classical three-point function of strings in AdS2 and show that one can apply a similar idea by making use of the classical integrability of the string sigma model on AdS2. The result is given in terms of the "massive" generalization of Gamma functions, which show up also in string theory on pp-wave backgrounds and the twistorial generalization of topological string.
The far ultraviolet (FUV) continuum flux is recognized as a very sensitive diag- nostic of the temperature structure of the Sun's lower chromosphere. Until now analysis of the available stellar FUV data has shown that solar-type stars must also have chromospheres, but quantitative analyses of stellar FUV continua require far higher quality spectra and comparison with new non-LTE chromosphere models. We present accurate far ultraviolet (FUV, 1150-1500^{\circ}) continuum flux measurements for solar-mass stars, made feasible by the high throughput and very low detector background of the Cosmic Origins Spectrograph (COS) on the Hubbble Space Telescope. We show that the continuum flux can be measured above the detector background even for the faintest star in our sample. We find a clear trend of increasing continuum brightness temperature at all FUV wavelengths with decreasing rotational period, which provides an important measure of magnetic heating rates in stellar chromospheres. Comparison with semiempirical solar flux models shows that the most rapidly rotating solar-mass stars have FUV continuum brightness temperatures similar to the brightest faculae seen on the Sun. The thermal structure of the brightest solar faculae therefore provides a first-order estimate of the thermal structure and heating rate for the most rapidly rotating solar-mass stars in our sample.
Exchange interaction within a quantum dot strongly affects the transport through it in the Kondo regime. In a striking difference with the results of the conventional model, where this interaction is neglected, here the temperature and magnetic field dependence of the conductance may become non-monotonic: its initial increase follows by a drop when temperature and magnetic field are lowered.
We show the coherence of the direct images of the De Rham complex relative to a flat holomorphic map with suitable boundary conditions. For this purpose, a notion of bi-dg-algbera called the Koszul-De Rham algbera is dveloped.
We report a CCD optical photometry of a dwarf nova AL Com in superoutburst. Before superhumps occurred the light curve was highly variable with dominant periods about 41 minutes and 81.5 minutes for different nights. The period of observed superhumps is 82.5 minutes and seems to be stable. The first harmonic of the basic period is also present. We detected a weak signal corresponding to period 78.1 minutes. One of the periods 78.1 or 81.5 is suspected to be a possible signature of orbital motion in the system.
Starting from the hypothesis that the Galaxy's dark halo responded adiabatically to the infall of baryons, we have constructed a self-consistent dynamical model of the Galaxy that satisfies a large number of observations, including measurements of gas terminal velocities and masers, the kinematics of a 180,000 giant stars from the RAVE survey, and star count data from the SDSS. The stellar disc and the dark halo are both specified by distribution functions (DFs) of the action integrals. The model is obtained by extending the work of Piffl Penoyre & Binney (2015} from the construction of a single model to a systematic search of model space. Whereas the model of Piffl et al violated constraints on the terminal-velocity curve, our model respects these constraints by adopting a long scale length R_d=3.66 kpc for the thin and thick discs. The model is, however, inconsistent with the measured optical depth for microlensing of bulge stars because it attributes too large a fraction of the density at R <~ 3 kpc to dark matter rather than stars. Moreover, it now seems likely that the thick disc's scale-length is significantly shorter than the model implies. Shortening this scale-length would cause the constraints from the rotation curve to be violated anew. We conclude that we can now rule out adiabatic compression of our Galaxy's dark halo.
Adding grains at a single site on a flat substrate in the Abelian sandpile models produce beautiful complex patterns. We study in detail the pattern produced by adding grains on a two-dimensional square lattice with directed edges (each site has two arrows directed inward and two outward), starting with a periodic background with half the sites occupied. The size of the pattern formed scales with the number of grains added $N$ as $\sqrt{N}$. We give exact characterization of the asymptotic pattern, in terms of the position and shape of different features of the pattern.
We propose an implementation of a universal quantum gate between pairs of spatially separated atoms in a microwave cavity at finite temperature. The gate results from reversible laser excitation of Rydberg states of atoms interacting with each other via exchange of virtual photons through a common cavity mode. Quantum interference of different transition paths between the two-atom ground and double-excited Rydberg states makes both the transition amplitude and resonance largely insensitive to the excitations in the microwave cavity "quantum bus" which can therefore be in any superposition or mixture of photon number states. Our scheme for attaining ultralong-range interactions and entanglement also applies to mesoscopic atomic ensembles in the Rydberg blockade regime and is scalable to many ensembles trapped within a centimeter sized microwave resonator.
We estimate the local density field in redshift shells to a maximum redshift of z=0.3, using photometric redshifts for the 2MASS galaxy catalogue, matched to optical data from the SuperCOSMOS galaxy catalogue. This density-field map is used to predict the Integrated Sachs-Wolfe (ISW) CMB anisotropies that originate within the volume at z<0.3. We investigate the impact of this estimated ISW foreground signal on large-scale anomalies in the WMAP CMB data. We find that removal of the foreground ISW signal from WMAP data reduces the significance of a number of reported large-scale anomalies in the CMB, including the low quadrupole power and the apparent alignment between the CMB quadrupole and octopole.
We show that a one-dimensional discrete time quantum walk can be used to implement a generalized measurement in terms of positive operator value measure (POVM) on a single qubit. More precisely, we show that for a single qubit any set of rank 1 and rank 2 POVM elements can be generated by a properly engineered quantum walk. In such a scenario the measurement of particle at position x=i corresponds to a measurement of a POVM element E_i on a qubit. We explicitly construct quantum walks implementing unambiguous state discrimination and SIC-POVM.
We address two finite size effects in perpendicular transport through magnetic multilayers. When the magnetic layer thickness in spin valves becomes of the order or smaller than the spin-flip diffusion length, structural asymmetries affect the transport properties. A magnetic layer with thickness approaching the magnetic coherence length becomes transparent for spin currents polarized perpendicular to the magnetization. We use the generalized magnetoelectronic circuit theory to investigate both effects on the angular magnetoresistance (aMR) and spin transfer torque. We analyze recent aMR experiments to determine the spin-flip diffusion length in the ferromagnet as well as the interface spin-mixing conductance and propose a method to measure the ferromagnetic coherence length.
A stable core-shell structure with Ih symmetry, Au12@Au30, has been investigated by first-principles calculations. It is composed of an icosahedron core and an icosidodecahedron shell. The stability of the core-shell Au42 structure is verified by vibrational frequency analysis and molecular dynamics NVT simulations. Both the frontier molecular orbitals and the spin density of states show obvious s-d hybridization characteristics. The adaptive natural density partitioning analysis demonstrate multi-center bonds, twenty 6-center {\sigma} bonds ,and one 12-center {\sigma} bond, which are of great importance for the core-shell structural stability. In this core-shell nanostructure, there are also a large number of one-center valence lone electron pairs with the characteristics of d-like orbitals, so that the proposed Au12@Au30 could be used in medicine and catalysis fields.