ShantanuT01/DACTYL-Pretraining huggingface dataset:
The detection of gravitational-wave signals from coalescing eccentric binary black holes would yield unprecedented information about the formation and evolution of compact binaries in specific scenarios, such as dynamical formation in dense stellar clusters and three-body interactions. The gravitational-wave searches by the ground-based interferometers, LIGO and Virgo, rely on analytical waveform models for binaries on quasicircular orbits. Eccentric merger waveform models are less developed, and only few numerical simulations of eccentric mergers are publicly available, but several eccentric inspiral models have been developed from the post-Newtonian expansion. Here we present a novel method to convert the dominant quadrupolar mode of any circular analytical binary-black-hole model into an eccentric model. First, using numerical simulations, we examine the additional amplitude and frequency modulations of eccentric signals that are not present in their circular counterparts. Subsequently, we identify suitable analytical descriptions of those modulations and interpolate key parameters from twelve numerical simulations designated as our training dataset. This allows us to reconstruct the modulated amplitude and phase of any waveform up to mass ratio 3 and eccentricity 0.2. We find that the minimum overlap of the new model with numerical simulations is around 0.98 over all of our test dataset that are scaled to a 50M$_\odot$ black-hole binary starting at 35 Hz with aLIGO A+ design sensitivity. A Python package \pyrex easily carries out the computation of this method.
We bound Selmer groups attached to Grossencharacters of CM elliptic curves by the appropriate $L$-value. Our method is to use Kato's explicit reciprocity law and the Main Conjecture as proved by Rubin. These results are then used together with work of Han and fundamental results of Nekovar to bound the torsion in the image of the $p$-adic cycle class map for self products of CM elliptic curves. Our results are valid for Chow groups of arbitrary codimension for almost all $p$.
Irradiation-induced lattice defects in silicon carbide (SiC) have already exceeded their previous reputation as purely performance-inhibiting. With their remarkable quantum properties, such as long room-temperature spin coherence and the possibility of downscaling to single-photon source level, they have proven to be promising candidates for a multitude of quantum information applications. One of the most crucial parameters of any quantum system is how long its quantum coherence can be preserved. By using the pulsed optically detected magnetic resonance (ODMR) technique, we investigate the spin-lattice relaxation time ($T_1$) and spin coherence time ($T_2$) of silicon vacancies in 4H-SiC created by neutron, electron and proton irradiation in a broad range of fluences. We also examine the effect of irradiation energy and sample annealing. We establish a robustness of the $T_1$ time against all types of irradiation and reveal a universal scaling of the $T_2$ time with the emitter density. Our results can be used to optimize the coherence properties of silicon vacancy qubits in SiC for specific tasks.
High energy scattering experiments involving nuclei are typically analyzed in terms of light front variables. The desire to provide realistic,relativistic wave functions expressed in terms of these variables led me to try to use light front dynamics to compute nuclear wave functions. Here calculations of infinite nuclear matter in the mean field approximation and also in a light front version of Bruckner theory which includes NN correlations are reviewed. Applications of these wave functions to nuclear deep inelastic scattering and Drell-Yan processes are discussed. We find that relativistic mean field theory produces no EMC binding effect.
Weak localization in graphene is studied as a function of carrier density in the range from 1 x $10^{11}$\,cm$^{-2}$ to 1.43 x $10^{13}$\,cm$^{-2}$ using devices produced by epitaxial growth onto SiC and CVD growth on thin metal film. The magnetic field dependent weak localization is found to be well fitted by theory, which is then used to analyse the dependence of the scattering lengths L$_\varphi$, L$_i$, and L$_*$ on carrier density. We find no significant carrier dependence for L$_\varphi$, a weak decrease for L$_i$ with increasing carrier density just beyond a large standard error, and a n$^{-\frac{1}{4}}$ dependence for L$_*$. We demonstrate that currents as low as 0.01\,nA are required in smaller devices to avoid hot-electron artefacts in measurements of the quantum corrections to conductivity.
We introduce a data analysis procedure for color transparency experiments which is considerably less model dependent than the transparency ratio method. The new method is based on fitting the shape of the A dependence of the nuclear cross section at fixed momentum transfer to determine the effective attenuation cross section for hadrons propagating through the nucleus. The procedure does not require assumptions about the hard scattering rate inside the nuclear medium. Instead, the hard scattering rate is deduced directly from the data. The only theoretical input necessary is in modelling the attenuation due to the nuclear medium, for which we use a simple exponential law. We apply this procedure to the Brookhaven experiment of Carroll et al and find that it clearly shows color transparency: the effective attenuation cross section in events with momentum transfer $Q^2$ is approximately $40\ mb\ (2.2\ GeV^2/Q^2)$. The fit to the data also supports the idea that the hard scattering inside the nuclear medium is closer to perturbative QCD predictions than is the scattering of isolated protons in free space. We also discuss the application of our approach to electroproduction experiments.
We consider models of anomaly-mediated supersymmetry breaking (AMSB) in which the grand unification (GUT) scale is determined by the vacuum expectation value of a chiral superfield. If the anomaly-mediated contributions to the potential are balanced by gravitational-strength interactions, we find a model-independent prediction for the GUT scale of order $M_{\rm Planck} / (16\pi^2)$. The GUT threshold also affects superpartner masses, and can easily give rise to realistic predictions if the GUT gauge group is asymptotically free. We give an explicit example of a model with these features, in which the doublet-triplet splitting problem is solved. The resulting superpartner spectrum is very different from that of previously considered AMSB models, with gaugino masses typically unifying at the GUT scale.
In a semi-infinite geometry, a 1D, M-component model of biological evolution realizes microscopically an inhomogeneous branching process for $M \to \infty$. This implies in particular a size distribution exponent $\tau'=7/4$ for avalanches starting at a free end of the evolutionary chain. A bulk--like behavior with $\tau'=3/2$ is restored if `conservative' boundary conditions strictly fix to its critical, bulk value the average number of species directly involved in an evolutionary avalanche by the mutating species located at the chain end. A two-site correlation function exponent ${\tau_R}'=4$ is also calculated exactly in the `dissipative' case, when one of the points is at the border. These results, together with accurate numerical determinations of the time recurrence exponent $\tau_{first}'$, show also that, no matter whether dissipation is present or not, boundary avalanches have the same space and time fractal dimensions as in the bulk, and their distribution exponents obey the basic scaling laws holding there.
We use profile decomposition to characterize 2-soliton solutions of the KdV equation as global minimizers to a constrained variational problem involving three of the polynomial conservation laws for the KdV equation.
The conformal-gauge two-dimensional quantum gravity is formulated in the framework of the BRS quantization and solved completely in the Heisenberg picture: All n-point Wightman functions are explicitly obtained. The field-equation anomaly is shown to exist as in other gauges, but there is no other subtlety. At the critical dimension D=26 of the bosonic string, the field-equation anomaly is shown to be absent. However, this result is not equivalent to the statement that the conformal anomaly is proportional to D-26. The existence of the FP-ghost number current anomaly is seen to be an illusion.
A scenario based on the electron cyclotron maser emission is proposed for the fine structures of solar radio emission in the present discussion. It is suggested that under certain conditions modulation of the ratio between the plasma frequency and electron gyro-frequency by ultra low frequency waves, which is a key parameter for excitation of the electron cyclotron maser instability, may lead to the intermittent emission of radio waves. As an example, the explanation of the observed fine-structure components in the solar type IIIb burst is discussed in detail. Three primary issues of the type IIIb bursts are addressed: 1) what is the physical mechanism that results in the intermittent emission elements that form a chain in the dynamic spectrum of type IIIb bursts, 2) what causes the split pair (or double stria) and the triple stria, 3) why in the events of fundamental-harmonic pair emission there is only IIIb-III, but IIIb-IIIb or III-IIIb cases are very rarely observed.
We present the results of the classification of spectral activity types for 193 galaxies from a new sample of 49 compact groups of galaxies in the southern hemisphere (SCGs). This sample was selected in automated fashion from a digitized galaxy catalogue, covering an area of ~5200 sq deg, around the South Galactic Pole. It is complete up to m ~14.5 in b_j for the brightest galaxy of the group.   The spectral analysis of the SCG galaxies confirms the results previously obtained for a smaller sample of Hickson's compact groups (HCG). We confirm the luminosity-activity and morphology-activity relations, as well as the predominance of AGNs (41% of SCGs galaxies). We verified also that the number of early-type non-emission-line galaxies increases with the number of members in the group.   The SCGs contain more star-forming galaxies (SFGs) and less non-emission-line galaxies than HCGs, which suggests that they probe a wider range of physical properties. The SFGs are composed in majority of HII Nucleus Galaxies, which have less intense star formation than starburst galaxies. The star formation activity in SCGs is, consequently, remarkably low. The SFGs show also evidence for nuclear activity. If these results are further confirmed, 70% of the galaxies in SCGs would then have an active nucleus, making these systems remarkably rich in AGNs. Curiously, however, this characteristic of CGs generally excludes Seyfert 1 galaxies.(Abridged)
We analyze an inhomogeneous system of coupled reaction-diffusion equations representing the dynamics of gene expression during differentiation of nerve cells. The outcome of this developmental phase is the formation of distinct functional areas separated by sharp and smooth boundaries. It proceeds through the competition between the expression of two genes whose expression is driven by monotonic gradients of chemicals, and the products of gene expression undergo local diffusion and drive gene expression in neighboring cells. The problem therefore falls in a more general setting of species in competition within a non-homogeneous medium. We show that in the limit of arbitrarily small diffusion, there exists a unique monotonic stationary solution, which splits the neural tissue into two winner-take-all parts at a precise boundary point: on both sides of the boundary, different neuronal types are present. In order to further characterize the location of this boundary, we use a blow-up of the system and define a traveling wave problem parametrized by the position within the monotonic gradient: the precise boundary location is given by the unique point in space at which the speed of the wave vanishes.
We review and clarify some cases of geometrical CP violation, the framework of spontaneous CP violation through complex phases with values that are independent of parameters of the potential. We present a flavour model based on Delta(27) featuring spontaneous CP violation, that can reproduce all quark masses and mixing data. The scalar sector of the model has exotic properties that can be tested at the LHC.
Super-hot looptop sources, detected in some large solar flares, are compact sources of HXR emission with spectra matching thermal electron populations exceeding 30 megakelvins. High observed emission measure, as well as inference of electron thermalization within the small source region, both provide evidence of high densities at the looptop; typically more than an order of magnitude above ambient. Where some investigators have suggested such density enhancement results from a rapid enhancement in the magnetic field strength, we propose an alternative model, based on Petschek reconnection, whereby looptop plasma is heated and compressed by slow magnetosonic shocks generated self-consistently through flux retraction following reconnection. Under steady conditions such shocks can enhance density by no more than a factor of four. These steady shock relations (Rankine-Hugoniot relations) turn out to be inapplicable to Petschek's model owing to transient effects of thermal conduction. The actual density enhancement can in fact exceed a factor of ten over the entire reconnection outflow. An ensemble of flux tubes retracting following reconnection at an ensemble of distinct sites will have a collective emission measure proportional to the rate of flux tube production. This rate, distinct from the local reconnection rate within a single tube, can be measured separately through flare ribbon motion. Typical flux transfer rates and loop parameters yield emission measures comparable to those observed in super-hot sources.
The Arecibo Legacy Fast ALFA (ALFALFA) survey is a program aimed at obtaining a census of HI-bearing objects over a cosmologically significant volume of the local universe. When complete in ~3-4 years, it will cover 7000 square degrees of high latitude sky using the 305m telescope and the seven-beam Arecibo L-band feed array (ALFA). As of May 1, 2008, almost 60% of the required observations are complete and a catalog exists in preliminary form for 25% of the final sky area. ALFALFA is detecting about twice as many HI sources as predicted based on previously published HI mass functions and should deliver a final catalog of >25000 extragalactic HI sources. ALFALFA will detect hundreds of galaxies with HI masses less than 10**7.5 solar masses and similarly large numbers greater than 10**10.3 Msun. Its centroiding accuracy allows for the immediate identification of highly probably optical counterparts to each HI detection. Fewer than 3% of all extragalactic HI sources, and < 1% of ones with HI masses > 10**9.5 Msun cannot be identified with a stellar counterpart. The hundreds of HI sources with observed line widths of 20-30 km/s include a population of optically faint dwarf galaxies. The objects with highest HI masses exhibit a range of morphologies, optical colors and surface brightnesses, but most appear to be massive disk systems. The latter represent the population likely to dominate future studies of HI at high redshift.
The electronic energy band spectra, as well as partial and total density of electronic states of the crystal argyrodite Ag$_{8}$SnSe$_{6}$ have been evaluated within the projector augmented waves (PAW) approach by means of the ABINIT code. The one-electron energies have been evaluated using two functionals for exchange-correlation energy. The first one is the generalized gradient approximation (GGA) approach. The second one is the hybrid functional PBE0 composed of the semilocal GGA part and Hartree-Fock exact exchange non-local energy for strongly correlated $4d$ electrons of Ag atom. The second approach eliminates the Coulomb self-interaction of the Ag $4d$ electrons. This leads to a significant restructuring of the energy bands in the filled valence part and to an improved location of the Ag $4d$-states on the energy scale, and the resulting value of the band gap is well compared with experiment. The effects of strong correlation on the electronic structure of the crystal argyrodite are considered here for the first time.
Linearized general relativity admits a formulation in terms of gravitoelectric and gravitomagnetic fields that closely parallels the description of the electromagnetic field by Maxwell's equations. For steady mass currents, this formalism has been used to understand gravitomagnetic effects like the Lense-Thirring dragging of inertial frames. For time-varying mass-energy currents, the analog of Faraday's law suggests new effects based on the gravitational equivalent of a transformer where such currents take the place of electrical currents. New experimental possibilities are suggested including a novel coupling mechanism of electromagnetism to gravity, new tests of general relativity in the ultrarelativistic limit using particle beams in the LHC, and searches for a materials exhibiting the gravitational analog of ferromagnetism.
A circle, centered at the origin and with radius chosen so that it has non-empty intersection with the integer lattice $\mathbb{Z}^{2}$, gives rise to a probability measure on the unit circle in a natural way. Such measures, and their weak limits, are said to be attainable from lattice points on circles.   We investigate the set of attainable measures and show that it contains all extreme points, in the sense of convex geometry, of the set of all probability measures that are invariant under some natural symmetries. Further, the set of attainable measures is closed under convolution, yet there exist symmetric probability measures that are not attainable. To show this, we study the geometry of projections onto a finite number of Fourier coefficients and find that the set of attainable measures has many singularities with a "fractal" structure. This complicated structure in some sense arises from prime powers - singularities do not occur for circles of radius $\sqrt{n}$ if $n$ is square free.
We present correct solution of the problem about a scattering of the neutron on a point-like defect existing in a medium and show that this mechanism cannot explain anomalous losses of UCN in storage bottles.
The distance of NGC1316, the brightest galaxy in Fornax, is an interesting test for the cosmological distance scale. First, because Fornax is the 2nd largest cluster of galaxies at <~25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC1316 is the galaxy with the largest number of detected SNeIa, giving the opportunity to test the consistency of SNeIa distances internally and against other indicators.   We measure SBF mags in NGC1316 from ground and space-based imaging data, providing a homogeneous set of measurements over a wide wavelength interval. The SBF, coupled with empirical and theoretical calibrations, are used to estimate the distance to the galaxy. We present the first B-band SBF measurements of NGC1316 and use them together with the optical and near-IR SBF data to analyze the properties of field stars.   Our distance modulus m-M=31.59 +-0.05(stat) +-0.14(sys), when placed in a consistent Cepheid distance scale, agrees with the results from other indicators. However, our result is ~17% larger than the most recent estimate based on SNeIa. Possible explanations for this disagreement are the uncertainties on internal extinction, or calibration issues. Concerning the stellar population analysis, we confirm earlier results from other indicators: the field stars in NGC1316 are dominated by a solar metallicity, intermediate age component. A substantial mismatch exists between B-band SBF models and data, a behavior that can be accounted for by an enhanced percentage of hot horizontal branch stars.   Our study of the SBF distance to NGC1316, and the comparison with distances from other indicators, raises some concern about the homogeneity between the calibrations of different indicators. If not properly placed in the same reference scale, significant differences can occur, with dramatic impact on the cosmological distance ladder.
Using two different experimental techniques, namely, chemical vapor deposition (CVD) and physical vapor deposition (PVD), we deposited a Lead sulphide (PbS) thin films with a very small lifetime. We investigated the morphology of the obtained PbS films using various techniques i.e.AFM, SEM, EDAX, AES and HRTEM . In the case of CVD, we found that the surface consists of grains with dimensions in the plane (diameter to 300 nm and height up to 200 nm), while the same order of the grain size has been observed for PVD. On the other hand, SEM investigation reveals that the PbS particles with various morphologies of both films have uniform and the particle size distribution. Small amount of Sodium was obtained from EDXS studies, which is may originate from the substrate where the deposition process has been produced at temperature 550-600 deg. and for CVD at minimum accelerating voltage 5kV silicon are presented in the spectrum, which means that the region for X-ray generation voltage data exceeds the thickness of the films (where the thickness of films about 0.4 micron). AES confirm that the surface layer of these films (PVD) containing carbon and oxygen and it has a thickness of 0.1micron. At a depth of 1.3 microns in films these elements is again increased, which corresponds to the film thickness of 1.5 micron. Layers of PVD films are seen by HRTEM and the studies confirm that oxygen-layer located on top of the structure, while the layers of CVD films have not only the oxygen along the crystallite boundaries, but also accumulate in the depth of the boundary with the substrate. Our results of morphology indicate that changing in spectral characteristics of films deposited by (CVD and PVD) is related to the structure and crystalline size.
The Lie group adiabatic evolution determined by a Lie algebra parameter dependent Hamiltonian is considered. It is demonstrated that in the case when the parameter space of the Hamiltonian is a homogeneous K\"ahler manifold its fundamental K\"ahler potentials completely determine Berry geometrical phase factor. Explicit expressions for Berry vector potentials (Berry connections) and Berry curvatures are obtained using the complex parametrization of the Hamiltonian parameter space. A general approach is exemplified by the Lie algebra Hamiltonians corresponding to SU(2) and SU(3) evolution groups.